For horizontal mining and exploration workings, two forms of cross sections are established: trapezoidal (T) and rectangular-vaulted with a duct vault (PS). On fig. 9-10 shows typical sections of mine workings of various shapes.

Distinguish the cross-sectional area of ​​horizontal workings in the light, in the sinking and in the rough. Clear area (S CB) - this is the area enclosed between the support of the working and its soil, minus the cross-sectional area, which is occupied by the ballast layer (if any) poured on the soil of the working.

The area in the penetration (5 pr) - the area of ​​​​the development, which it turns out in the process of carrying out before the construction of the lining, rail track laying, the installation of the ballast layer and the laying of engineering communications (cables, air, water pipes, etc.). Area in draft (S BH) - the area of ​​production, which is obtained in the calculation (design area).

Permissible excesses of the area in the penetration over the design one (roughly) are given in Table. 2.

table 2

Rice. 9.1. A typical section of workings of a trapezoidal shape with wooden lining: a - scraper delivery of rock; b - conveyor delivery of rock; c - manual haulage of rock; d - locomotive haulage of rock; e - double-track development with locomotive haulage of rock

Rice. 10. Typical section of workings with monolithic concrete lining with locomotive haulage of rock: a - single-track; b - two-way

Rice. 9.2. Typical section of rectangular-vaulted workings without fastening or with anchor (sprayed-concrete) fastening: a - scraper rock delivery; b - conveyor delivery of rock; c - manual haulage of rock; G - locomotive rock haulage; e - double-track development with a locomotive

rock haulage

Thus, the cross-sectional area of ​​the working in the penetration

or, on the other hand,

As S B4 = S CB + S Kp, then the calculation of the cross-sectional area of ​​​​the working begins with the calculation in the light, where S Kp- section of the working, occupied by the lining; K p- cross-section enumeration coefficient (section excess coefficient - KIS).

The dimensions of the cross-sectional area of ​​horizontal workings in the light are determined based on the conditions for the placement of transport equipment and other devices, taking into account the necessary clearances regulated by the Safety Rules.

In this case, it is necessary to consider the following possible cases of workings and calculation of the section:

• 1. The road is secured and the loader is working in the fixed road. In this case, the calculation is carried out according to the largest dimensions of the rolling stock or loading machine.
• 2. The working is traversed with fastening, but the lining lags behind the face by more than 3 m. In this case, the loading machine works in the loose part of the working.

When calculating the dimensions of the cross-sectional area according to the largest dimensions of the rolling stock, it is necessary to make a verification calculation (Fig. 11):

The interpretation of the data is given below (Table 5).

3. Working out is passed without fastening. Then the dimensions of the section are calculated according to the largest dimensions of the tunneling equipment or rolling stock.

The main dimensions of underground vehicles are standardized in order to typify the sections of workings, the design of the lining and tunneling equipment.

For workings of a trapezoidal shape, standard sections have been developed with the use of solid lining, lining in different directions, with tightening only the roof and with tightening the roof and sides.

Typical sections of rectangular-vaulted workings are provided without support, with anchor, sprayed concrete and combined support.

The main dimensions of typical sections of workings of the T and PS types are given in Table. 3 and 4.

Table 3

The main dimensions of the sections of workings of a trapezoidal shape (T)

Designated	Section dimensions, mm				Designated	Section dimensions, mm
				Sectional area in the light, m ​​2					Sectional area in the light, m ​​2

Table 4

The main dimensions of the sections of workings of rectangular-vaulted

forms (PS)

Designation	Section dimensions, mm					Sectional area in the light, m ​​2

Rice. Fig. 11. Schemes of the working conditions of the loading machine in the face: a - in an unsecured bottomhole space; b - in the fixed bottomhole space

Calculation formulas for determining the dimensions of the sections of workings of types T and PS are given in table. 5, 6.

Table 5

Trapezoidal workings

		Designation	Calculation formulas
	Transport equipment		Selected from catalogs
	free passage
	From soil to head rail		h =hi + h p + 1/3 /g w
	Ballast layer (ladder)
	Workings from the rail head		are chosen
	up to the top		in accordance with the PB
	Works in the world:
	without rail track
	when scraping rock
	during conveyor delivery of rock		h 4 \u003d h + hi
	in the presence of a rail track:
	without ballast layer		h 4 = h + hi
	with ballast layer		h 4 = h+ L3-L2
	Rough workings:
	without ballast layer		hs = h4 + d + ti
	with ballast layer		hs = h 4 + h + d + ti
	Transport equipment		From equipment catalogs
	Free passage at height h		Selected in accordance with the PB
	Passage at the level of transport equipment
	In light at the level of transport equipment:
	for scraper cleaning		b = b + 2m
	single track		b = b + t + n
	double track		b \u003d 2B + c + m-p
	Workings in the clear on the top: without rail track		b = b-2(h-H) ctga
	with a rail track		B=b- 2(hi - H) ctga
	Sole:
	without rail track		bi = b + 2H ctga
	in the presence of a rail track without a ballast layer		Z>2 = 6 + 2(#+/ji)ctga
	with ballast layer		Z>2 = 6 + 2(#+/ji)ctga

		Designation	Calculation formulas
	Rough workings:
	top base		bz = b+2 (d+ t2) sina
	bottom base with ballast layer	ba	ba = bz +2 hs ctga
	without ballast layer		ba = b 2 + 2 (d + t2) sina
	Between transport equipment		Selected according to the PB
	eat and the wall of the workings		(t> 250 mm with> 200 mm)
	Between rolling stock
	Rack, top made of round timber
			Estimated
Distance, mm	From the axis of the track (conveyor) to the axis of production: single-track		k = (u + s2 )-S2
	double track		k = s2 -(u+s2 )
	Cross section: clear		R= b+ 62 + 2L4/sin a
			Pi = bz+ ba + 2/r5/sin a
	Cross section: clear		S CB = /24(61 +b 2 )l2
			Sm = /25(63 + 6 4)/2

Table 6

Rectangular-vaulted workings

		Designation	Calculation formulas
	with sprayed concrete, rod and combined supports		ho=bl4
	with concrete support		ho = b/2
	Works in the world:
	without rail track:
	when scraping rock		h 4= h + ho
	with conveyor		h 4 \u003d h + /?2 + ho
	in the presence of a rail track: without ballast layer		h 4 = h+ /?2 + ho
	with ballast layer		h 4= h + ho
	Developments in draft		hs= h+ hi + ho +1
	Working walls in rough:
	when scraping rock
	with ballast layer (ladder)		he = h+ hi
	Transport equipment		Selected from catalogs
	Works in the world:
	single track		b=B+ m+n
	double track		b = 2B + c + m + n
	Developments in draft		bo = b + 2t
	Axial arc of the vault:
	at ho = N4		R = 0.%5b
	at ho= S 3		R= 0,6926
	Lateral arch:
	at ho = YA		r= 0,1736
	at ho = Yb		r = 0.262b
Perimeter transverse workings,
	at ho = YA: without ballast layer		P = 2he+ 1,219
	with ballast layer at ho = b/3: without ballast layer		P = 2h+ 1,219 P = 2he + 1,33 b
	with ballast layer		P = 2h+ 1,33 b

		Designation	Calculation formulas
Perimeter transverse workings,	In draft: at ho = N4 at ho = s 3		/>1=2*6+1,19*0 />! = 2*6+1,33 bo
Cross-sectional area of ​​the mine, m 2
	at ho = YA at ho = S 3		S CB = b(h + 0.15b) S CB = b(h + 0.2b)
	without support or rod support		SB4= b(h 6 +0,n5b)
	with sprayed-concrete and combined lining with concrete lining of a rectangular part of the working		SB4= bo(h 6 +0.15b)S B h = S CB + S+ S 2 + S3 S= 2A 6 /[
	vaulted part of the working		S 2 = 0.157(1 + Ao/6)(6i 2 -6 2)
	subsoil part of the lining	S3	Si = 2/27/+ hg(t)-t)
Dimensions of the subsoil part of the support			Selected depending on the properties of rocks and width
	Cutting height		workings

All horizontal workings along which cargo is transported must have gaps in straight sections between the support or equipment located in the working, pipelines and the most protruding edge of the rolling stock clearance of at least 0.7 m (n > 0.7) (free passage for people), and on the other hand - at least 0.25 m (t > 0.25) with wooden, metal and frame structures of reinforced concrete and concrete lining and 0.2 m - with monolithic concrete, stone and reinforced concrete lining.

The width of the free passage must be maintained at a working height of at least 1.8 m (h = 1,8).

In workings with conveyor delivery, the width of the free passage should be at least 0.7 m; on the other hand - 0.4 m.

The distance from the upper plane of the conveyor belt to the top or roof of the working is at least 0.5 m, and for tension and drive heads - at least 0.6 m.

Gap with between oncoming electric locomotives (trolleys) along the most protruding edge - at least 0.2 m (with> 0.2 m).

In places of coupling-uncoupling of trolleys, the distance from the support or equipment and pipelines located in the workings to the most protruding edge of the rolling stock gauge must be at least 0.7 m on both sides of the working.

When rolling by contact electric locomotives, the height of the contact wire suspension must be at least 1.8 m from the rail head. At landing and loading and unloading sites, at the intersection of workings with workings, where there is a contact wire and along which people move - at least 2 m.

In the near-shaft yard - in places where people move to the landing site - the suspension height is at least 2.2 m, in the other near-shaft workings - at least 2 m from the rail head.

In near-shaft yards, in the main haulage workings, in inclined shafts and slopes, when using trolleys with a capacity of up to 2.2 m 3, R-24 type rails should be used.

Mine rail tracks during locomotive haulage, with the exception of workings with heaving soil and with a service life of less than 2 years, must be laid on crushed stone or gravel ballast from hard rocks with a layer thickness under the sleepers of at least 90 mm.

Carrying out with separate excavation of layers of rocks or coal and host rocks - a scheme in which first a coal seam or a certain layer is taken out on a certain excavation and then host rocks or other layers. Carrying out by a wide slaughter - a scheme in which coal is excavated outside the working section with placement of waste rock in the formed space. The use of domestic combines is advisable when carrying out mine workings along a coal seam with a small percentage of rock undercutting with a strength of f up to 7 and an inclination angle of up to...

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LECTURE #19

Conducting mining (part 1)

General issues of workings.

Mining- a complex of processes for breaking, loading, transporting rock mass, erecting lining, ventilation, building up transport devices and communications. Providing exploits of the preparatory slaughter.

The method of carrying out the development- a set of technical solutions for breaking, loading rock mass and fixing the face, the implementation of which allows for the development of working in certain mining and geological conditions. Methods of carrying out are divided into ordinary and special.

Conventional ways - ways of working in stable rocks, allowing them to be exposed for a certain time.

Special Ways- methods of working in loose rocks and rocks with elevated water cut.

Technological scheme of development- a certain order of production processes, coordinated in space and time, means of their mechanization and equipment placement corresponding to this order.

Technological schemes of workings are divided into:

• Sinking schemes for homogeneous rocks;
• Schemes of driving through heterogeneous rocks.

Homogeneous rock- a breed whose strength is approximately the same throughout the face.

Heterogeneous breed- a set of rock layers, the properties of which are different in the section of the stope. A typical example of a heterogeneous rock is a coal mine with a hairstyle of roof rocks. (soils)

Carrying out continuous slaughter- a scheme for working out, in which the breaking (excavation) of rocks is carried out simultaneously throughout the face.

Carrying out with a split notchrock layers or coal and wall rocks – a scheme in which, first, a coal seam or a certain layer is taken out for a certain excavation, and then the host rocks or other layers.

Carrying out a narrow face- a scheme in which the excavation of the rock mass is carried out only within the cross section of the working.

Carrying out a wide face- a scheme in which coal is excavated outside the working section with placement of waste rock in the formed space.

The shape and dimensions of the cross section of workings

Working section- an image in the drawing on a certain scale of the contour of the working, lining, equipment, tracks and communications, obtained as a result of the intersection of the working with a plane. Sections differ in the form of cutting planes. For a longitudinal section, the secant plane passes along the axis of the working. For a cross section, the cutting plane runs perpendicular to the mine axis.

Section in penetration- section of the working after excavation of the rock mass before the installation of the support along the contour of the host rocks.

Section in draft - section along the outer contour of the lining and the working soil.

clear section - section after the erection of the lining and laying of the rail track along the inner contour of the lining and the top of the ballast layer, and in its absence - along the soil.

The shape of the cross section of the mine is determined by:

• The properties of rocks;
• The magnitude and nature of the manifestation of rock pressure;
• Support design;
• Appointment;
• Working life;
• The way the production is carried out.

Depending on the cross-sectional shape of the workings, there are: rectangular (a), trapezoidal and polygonal (b-d). Horizontal workings are usually fixed with wooden, metal or prefabricated rails./ b fasten.

The vaulted cross-sectional shape (e-m) has workings fixed by an arch or w/ b fasten.

Vertical workings are most often rectangular (a) or round (n) in shape and are fixed with concrete or tubing lining.

The cross-sectional area of ​​the working is determined by:

• Dimensions of operational equipment or vehicles;
• Gaps between the contours of the support and the dimensions of the vehicle equipment;
• Gaps between the dimensions of equipment and vehicles;
• The size of the passage for people.

All clearances are given in §88 PB.

For the movement of people in the working, a passage is left at least 0.7 m wide at a height of 1.8 m from the sidewalk, the top of the ballast layer or the soil.

The minimum cross-sectional area of ​​the working is 4.5m 2 (§88 PB)

• The amount of air that is planned to be supplied to the production.

Materials for fixing mine workings.

The following are used as materials for lining mine workings:

• Metal; Concrete; Reinforced concrete; Wood; Brick; Plastic concrete; Carbon fiber;
• Fiberglass; Dr. polymer materials.

Metal - for mine lining, they are used in the form of profile rolled products from low-alloy or low-carbon steels (Art. 5)

SVP 6 standard sizes are produced with a weight of 1 r.m. 14,17,19,22,27, and 33 kg.

In addition to rolled metal, metal tubings are produced - segments having a curved plate (wall) and stiffeners.

Concrete - artificial stone material containing binders (cement, gypsum cement), fine aggregate, coarse aggregate and water.

Sand is used as a fine aggregate, strong gravel or crushed stone is used as a coarse aggregate.

The composition of concrete is determined by the content of weight parts of cement, sand (A) and coarse aggregate (B)

1:A:B

And also according to the ratio of the mixed amount of water (W) and cement (C)/ C

Grade of cement - compressive strength of the sample in tenths of MPa, made from one part of cement and three parts of sand at V/ C \u003d 1: 2.5

Portland cement grades 400, 500, and 600 are most widely used (rarely 300)

At the cost of cooking 1m 3 concrete less than 200 kg concrete is called lean;

200 - 250kg - medium

Over 250kg - fat.

Reinforced concrete - a single artificial metal-stone material, consisting of concrete and metal reinforcement.

Forest materials- used for fixing workings with a service life of 2 - 3 years.

Pine, spruce, fir, cedar, larch are used for fixing workings.

The main type of wooden support is the ore rack ø 7 - 34cm, length 0.5 - 7m.

lumber : cuts, beams, slabs, boards are obtained by sawing ores of racks (logs).

The specific tensile strength of timber is~ 10MPa, for compression - 13MPa.

Brick - for fixing workings, grades 150 and 175 are used; brick density in masonry 1800kg/ m 3 .

Concrete - concrete stones from ordinary or silicate concrete and blast-furnace slag. Brand of betonites - not less than 150.

LECTURE #20

Mining (Part 2)

The concept of processes and operations in the conduct of preparatory workings

Process - work clearly defined in its technical and organizational content, consisting of separate parts (operations) performed in a certain sequence.

Operation - a set of working methods, characterized by the constancy of the place of performance and performers.

Core Processes- processes that are carried out directly in the working face and are intended to change the shape and state of the face (separation of the rock mass from the massif and the fastening of the face).

Helper Processes- processes that ensure the efficient and safe execution of the main ones.

The main and auxiliary processes can be performed sequentially or combined.

Based on the possibility of overlapping in time, there are:

• flow technology (PT);
• cyclic technology (DH).

Flow technology is a technology in which the execution of the main processes (operations) is combined in time.

Cyclic technology is a technology in which the execution of the main processes (operations) is carried out sequentially.

Tunneling cycle and its main parameters

Tunnel cycle- a set of processes and operations, as a result of which the face moves in a certain time for a distance determined by the passport.

Cycle duration- the time during which all the main technological processes of the tunneling cycle are performed.

The duration of the tunneling cycle is usually taken as a multiple shift, which simplifies the organization of work.

Face advance per cycle- the distance that the face moves after all the processes included in the cycle are completed.

Carrying out horizontal and inclined mine workings

in rocks of strong and medium strength

Technology of mining in rocks with a fortress f more than 6.7 includes processes:

• drilling and blasting (BVR);
• airing the face and bringing it to a safe state;
• construction of temporary support;
• loading of rock mass;
• erection of a permanent support;
• ancillary work.

The following requirements apply to BVR:

• uniform crushing of the rock mass;
• small waste of rock from the face.

Drilling and blasting parameters are determined for each face individually and recorded in the drilling and blasting passport.

After the production of drilling and ventilation and airing, they begin to erect a temporary lining (a structure that ensures safe work in the preparatory face before the erection of a permanent lining).

For loading broken rock mass, special rock-loading machines on caterpillar or wheel-rail tracks are used.

Loading of broken rock mass can be carried out directly into trolleys or in stages through loaders of a special design.

Supporting a mine working (construction of a permanent support)

Depending on the type and material, the support is divided into:

• metal;
• reinforced concrete;
• wooden;
• stone;
• anchor;
• mixed, etc.

According to their characteristics, supports are rigid and pliable.

Rigid supports - the total deformation should not go beyond the limits of elasticity. Typically, these supports are used in workings with established rock pressure.

malleable - supports with special compliance nodes, due to which the amount of displacement of the elements of the support exceeds the amount of elastic deformations.

Recently, the most widely used anchor support, which allows you to increase the stability of the rocks of the roof and sides of the working by "stitching" several layers with special rods. Fixation of the anchor part of the anchor in the rocks occurs with the help of metal structures or concrete, polymer compositions.

To support the workings in the areas of heaving rocks, a lining is used with the addition of a "bed" - an additional element that closes the contour of the lining from the side of the soil.

To prevent rock fall from the side of the roof, a lattice, wooden, polymeric or reinforced concrete tightening is used.

After the completion of the main cycle, auxiliary processes begin:

• extension of ventilation pipes;
• downhole conduit;
• rail tracks, scraper conveyor;
• oslantsovka face and development.

After the completion of the auxiliary processes, the tunneling cycle is repeated.

Advantages drilling and blasting method:

• wide range of application;
• the possibility of conducting shock blasting on outburst hazardous formations.

disadvantages drilling and blasting method:

• multi-operation technology;
• relatively low rates of workings;
• additional danger in the conduct of BVR.

Combined way of workings

The main difference between the combine method of workings and drilling and drilling is the possibility of combining the process of rock mass breaking and shipment by a tunneling machine.

The most widely used are roadheaders on caterpillar tracks with an arrow-shaped executive body of a crown type and a scraper reloader.

Scheme of a roadheader of selective action. 1 - breaking crown, 2 - executive body, 3 - hydraulic jack, 4 - housing, 5 - electrical equipment, 6 - control bullets, 7 - scraper conveyor, 8 - rear support cylinder, 9 - running bogie, 10 - front support cylinder, 11 - loading device.

The use of domestic combines is advisable when carrying out mine workings along a coal seam with a small percentage of rock undercutting with a strength f up to 7 and tilt angle up to -20 0 and up to +20 0 in rebellion.

The crushed rock mass is loaded onto a scraper or belt conveyor directly by a combine harvester or using a special loader.

Advantages combine method:

• low operational efficiency;
• high penetration rates;
• ensuring the safety of mining operations.

disadvantages combine method:

• limited range of application (by fall, rise).

LECTURE №21

Cleaning work in coal mines

Cleaning works include processes for: extraction and transportation of PI;

bottomhole fixing; roof management.

Cleaning excavation - a set of breaking processes (separation from the massif), loading broken rock mass onto a face vehicle, delivery of PI from the face to the transport working.

stope - mining, intended for the extraction of PI.

Distinguish between long stopes (lavas) and short ones (gates and chambers).

Long stope- an extended production working of a linear or ledge shape, one side of which is limited by a coal massif, and the other by a support on the border with the goaf; the roof and soil are host rocks.

In long working faces, coal is excavated according to flank and frontal schemes.

flank scheme - the separation of coal from the array is carried out in a narrow area (at one point) of the production face.

Front circuit- the movement of the mining machine perpendicular to the direction of advance of the face and take out a strip of coal of a certain width (width). With the frontal scheme, separation from the massif is carried out by a mining unit simultaneously along the entire length of the stope. The direction of movement of the unit in this case coincides with the direction of advancing the stope.

According to the width of the capture, they distinguish:

• narrow-cut excavation - 0.5 - 1.0 m;
• wide-grip - more than 1.0 m;
• plow - 0.03 - 0.15 m.

With a narrow and wide-cut recess, coal is separated from the massif by cutting, with a plow - by chipping.

Short stope- working with a face of small length, limited on the sides by a coal massif or whole coal. Transport and ventilation workings adjacent to the stope are called excavation.

According to the location of stopes relative to the formation elements, stopes are distinguished: by dip; along the stretch; by rebellion; across stretch; diagonal.

Coal transport in longwall faces it is produced:

• in longwalls of flat and inclined seams - by scraper conveyors or conveyor-plow extraction units;
• in long working faces of steep and steep seams - by gravity along the soil; by gravity along special gutters; conveyor cutters of mining units;
• in short longwalls - scraper conveyors, loading and hauling machines (self-propelled trolleys), hydraulic transport.

Scheme of placement of equipment in the longwall:

1 – upper drive head of the face conveyor;

2 - upper niche; 3- becoming a face conveyor; 4- narrow-cut shearer; 5 - the executive body of the combine; 6 - lower niche; 7 – bottom drive head of the face conveyor; 8 - face conveyor in the transport working.

Ways to control the roof in longwalls

roof management- a set of measures to regulate the load on the lining of the stope, carried out for the efficient and safe extraction of PI.

There are ways to manage the roof: complete collapse; partial collapse; partial bookmark; full bookmark; smooth lowering.

Roof collapse method

The method is recommended for moderately and easily collapsing rocks of the immediate roof, when their power is sufficient to inflate the main roof. When the bottom-hole (mechanized) lining is removed, the roof rocks collapse in the goaf. The step of the primary landing is the advancement of the stope from the cutting furnace (mounting chamber), until the collapse of the rocks of the main roof. This is the most common way to control roof collapse. If self-collapse of the roof rocks during the movement does not occur (hanging), then a forced landing is used, for example, BVR.

disadvantages : difficulty with difficult-to-collapse roofs;

• impossibility of application when working on objects on the surface.

Partial collapse methodrecommended for use in the presence of easily collapsible rocks of the immediate roof of small thickness and the tendency of the rocks of the main roof to periodic collapse.

With this method, rubble strips being constructed are used with a width of 4-6 m, the distance between the strips is up to 15 m.

Partial bookmark methodmined-out space is used for hard-to-crush rocks. Rubble strips are erected to restrain the collapse of the roof rocks. On flat seams, rubble strips are located along strike, on steep ones - both along strike and dip

Full bookmark methodit is recommended, if necessary, to prevent the collapse of the host rocks after the excavation of the PI. It is used when it is necessary to prevent subsidence of the earth's surface.

Full bookmark allows you to:

• avoid subsidence of the earth's surface;
• avoid air leaks into the mined-out space;
• reduce the likelihood of rock burst.

disadvantages - high labor intensity and cost of work.

Soft lowering methodroof rocks are used on seams up to 1.2 m thick with heaving soils and weak roof rocks prone to smooth deflection.

LECTURE #22

Cleaning operations in the development of flat and inclined seams

Peculiarities of treatment works in the development of flat and inclined seams

The main features that characterize the technologies for mining flat and inclined seams are:

• Good conditions for the use of modern technical means, in particular, means of complex mechanization;
• Possibility of using the method of controlling the roof by complete collapse;
• Possibility of using effective ventilation schemes and gas controls to achieve high loads on the stope;
• Wide opportunities for partial and full automation of cleaning works.

Cleaning operations during longwall mining

The main technologies for mining flat and inclined seams with longwall faces are:

• Integrated - mechanized coal mining (75%);
• Mining with narrow-cut combines with individual support (6%);
• Extraction of coal by plows with individual support (2%);
• Extraction of coal by wide-cut combines with individual support (2%);
• Extraction of coal on explosives with individual support (10%);
• Extraction of coal with jackhammers with individual support (1%);
• Other technologies (auger, etc.). (4%).

Extraction of coal with a narrow-cut combine with individual support and as part of OMK

The complex is a set of certain mining equipment, transport equipment and powered roof support, linked according to the main technical parameters.

Small distribution received complexes consisting of:

• narrow-grip mining machine (combine or plow);
• Curving face conveyor;
• Hydroficated bottomhole support;
• Hydroficated lining of interfaces.

Mining machineis a combined mining machine that simultaneously performs work on separating coal from an array, crushing it and loading it onto a face conveyor. The executive body of a narrow-cut harvester is an auger, which is a screw Ø 0.56 - 2.0 m (diameter along the cutters) on the ledges of which cutters are installed in special tool holders (knuckles). When the auger rotates, the cutters separate the coal from the face, and the auger blades load the broken coal onto the scraper conveyor. The harvester can move on the ground or along the frame of the face conveyor. Combines working from the soil of the stope are used on very thin and thin seams. The harvester operating from the frame of the face conveyor from the side of the face has support skis and grippers that do not allow the combine to move when coal is excavated.

The shearer moves along the table of the face conveyor when the lantern wheel rolls along the rail, fixed on the face hole or fixed on the peak chain conveyor heads. When mining thin seams, along with combines with auger operating elements, combines with drum operating elements are used. Loading of coal when using drum executive bodies is carried out with the help of special loading shields.

Extraction of coal in a longwall, equipped with a narrow-cut shearer, is carried out as follows. In the initial position, the harvester is brought into niche 6, the conveyor and support are moved to the face, niche 2 is framed. The harvester starts moving upwards with a strip of coal. Following the combine, with a certain lag, the support moves in. After the harvester enters the upper niche, the combine begins to move down with cleaning the soil. Following the harvester with a lag of 10-12m, the conveyor moves in. When the harvester returns to the lowest point of the lava, the cycle repeats. This scheme of coal mining is called one-sided. With the shuttle scheme, coal is excavated when the combine moves in both directions.

Extraction cycle - a set of processes and operations that are periodically repeated during coal mining along the entire length of the working face, after which the face moves a certain distance. A scraper conveyor is used to transport coal along the working face. The scraper conveyor consists of: Traction body; Reshtachny stav; natural stations (stations); end station.

The operation of the scraper conveyor is based on the principle of moving a load by dragging when an endless chain with scrapers moves along special chutes (pans). According to the method of movement, following the advancement of the stope, conveyors are divided into bending and portable. Curving conveyors allow to move without disassembly becoming a distance of up to 1m in a length interval of 10-15m.

Stope fixing- the process of installing special structures supporting the roof (and soil), providing conditions for the safe work of people and the efficient operation of mining equipment. The following types of stope fastening are used: Landing at bottom hole support; Sectional powered support; Complete powered support; Aggregate mechanized support.

An individual support consists of posts installed between the roof and the ground, and top racks installed between the roof and the post. The frame consists of a top rack and one, two or more racks. The tops can be oriented along the dip or along the strike of the formation. The roof of the working between the tops is tightened with a puff.

Individual supports may have different designs and dependencies between the reaction h and drawdowns ∆ h . Support stiffness tgβ = h/ ∆ h; Support compliance∆h/h;

According to A.A. Borisov, all supports are divided into three types:

I type - 0 fortify the growing resistance, they have h=ƒ(tgβ);

II type – tg=0 - fasten constant resistance, they have h=const;

III type tgβ→∞ - rigid supports. RH- the initial resistance created in the rack when it is installed; RP- working resistance - the average value of the maximum allowable resistance of the rack to lowering the roof.

Under the action of the pressure of the roof rocks, the length of the rack is reduced by the amount of landing of the rack. After the maximum landing, the bearing capacity of the rack is exhausted and its destruction begins.Mechanized supportstope is called a moving mechanically hydroficated lining, consisting of kinematically interconnected bearing supporting and enclosing elements. Mechanized roof support is designed for mechanized fastening of the roof and movement of the roof support.

LECTURE #23

Cleaning works on steeply sloping and steep seams.

Peculiarities of cleaning operations on steep and steep seams

1. The possibility of using gravity transport of coal along the face when mining along strike and along adjacent workings when mining along the fall.
2. The need to fix both the roof and the soil during the cleaning work.
3. The complexity of the mechanization of cleaning operations on steep and steep seams.
4. Difficulty in ventilating stopes, caused by large air leaks due to the presence of aerodynamic connection with the surface.

Increased fire hazard of mining steep and steep seams, caused by large losses of coal.

Main technological schemesmining of steep and steep seams are:

• Ceiling-ledged face along the strike when extracting coal with jackhammers;
• Straight face along strike with coal excavation using explosives;
• Rectangular faces along the strike when mining coal with narrow-cut combines and conveyor-plows;
• Straight faces along the fall when extracting coal by units with conveyor - plows.
• Shield development system.
• Hydrotechnologies in the version of the Russian Geographical Society.

Development of steeply sloping and steep seams by ceiling-shouldered face

In each ledge, coal is excavated in strips equal to the width of the ledge. Pneumatic breaking hammers OM 5PM, OM 6PM and OM 7PM are used for breaking coal. To ensure safe working conditions, the ledge is protected from the flow of broken coal in the upper part from the overlying ledges with boards. The extraction of coal in the ledge is carried out from top to bottom with the obligatory fastening of the overhanging coal mass with ore racks and boards. When bottom hole support is installed in the form of one or two rows of ore racks for growing. With weak soil, the racks are installed on wooden beds. In ceiling ledges, the following methods of roof control are used:

• Complete collapse (0.6 - 1.3 m).
• Smooth lowering (0.5 - 0.7 m).
• Bookmark (1.3 - 2.2 m).
• Retention on fires (0.6 - 1.4 m).

Development of steeply sloping and steep seams by straight face along strike

Coal mining is carried out by specialized shearers; The face is inclined towards the advance by 10-15 0 . The lava is divided into the upper combine (approximately 2/3) and the lower magazine part.

The excavation of coal in the upper part is carried out by combines of the "Temp" and "Search" type from the bottom up. The movement of the harvester along the face is carried out by a winch rope installed on the ventilation shaft. Along with the working rope, a safety rope is used to hold the combine in the event of a break in the working rope.

The lower part of the lava is designed in the form of one to three magazine ledges 10 m long and 6 m wide, which serve to accumulate broken coal.

For mining steep and steep seams, the KGU-D complex (0.6-1.5 m) and the AK-3 unit (1.6-2.5 m) are used.

Development of seams by a straight face, moving down the fall

Downhole working out can be carried out by units of type 1 ANSHMK and 2 ANSHMK in the power range of 0.7 - 2.2 m. The length of the stope is 40 - 60 m.

The ventilation furnace is formed as the unit is moved by the fur with the support

The composition of the shield mining unit includes: Conveyor-plow; Mechanized support; Hydraulic equipment; Electrical (pneumatic) equipment; Remote control equipment.

The conveyor plow is an endless round-link saw-shaped chain, on which carriages equipped with cutters are fixed. The chain moves along a special guide beam. First of all, a pack of coal is removed from the roof. After that, when introduced into the array due to hydraulic feed jacks, the coal is destroyed by the cutters, and the coal is transported to the coal-fired furnace due to the translational movement of the carriages. The unit is moved by removing the spacer from the sections and moving them down the fall to the conveyor plow.

Shield Development System m > 2.0 m and a > 55 0 .

shield lining - mobile structureconsisting of metal beams that form a "frame" around the perimeter of the section, knurled beams, ties and clamps connecting the structure into a single whole.

Between themselves, the individual sections are connected by segments of the rope. Shields consist of 4-5 sections. Each section has a strike size of 6.0 m.

The shield support protects the face from falling rocks and perceives their load. The excavation of coal under the shield is carried out using explosives. The excavation of coal consists of: expansion of the shield ditch; blasting of supporting pillars; shield landing.

Shield mining systems are widely used in the Prokopievsko-Kiselevsk region of Kuzbass and in the mines of the Far East.

LECTURE #24

The concept of the technological scheme of the mine

General concepts and definitions

Technological scheme of the mine (TSSH)- a set of mine workings, surface buildings and structures with machines and mechanisms located in them, the joint operation of which ensures efficient and safe coal mining.

The main elements of TSS are:

stopes; Preparatory faces; Mineral transportation system; Delivery system for people, materials and equipment; Filling material supply system; Ventilation system; Drainage system; Coal seam degassing system; Mine lift. The parameters of each of the elements are selected (calculated) in such a way that coal production is maximum. The element of the technological scheme that restrains coal mining is commonly called“bottleneck” in TSS.

Cleaning conv. Transport Ventilation Lifting

bottom hole 2000t/ day 1500t / day

A day = 2000t / day A day = 2500t / day

Low place TSH.

Main transport

Under the main transport is understood a set of technical means, mine workings and underground structures that ensure the delivery of coal from the extraction site to the OSD or to the surface.

In the system of general mine transport, belt conveyors with a wide belt of 800, 1000, 1200 mm are most often used.

Modern belt conveyorshave a delivery length of 500-1500m and work in workings with inclination angles from -16 to +25 .

The productivity of belt conveyors is 420 - 1600/ hour.

To improve the reliability of the conveyor lines, intermediate bunkers with a capacity of 50-300m3 are arranged between the conveyors. 3 . Drive power is 50-250 kW.

Along with belt conveyors for transporting coal along horizontal workings, a number of mines uselocomotive haulage.

When using locomotive haulage, minerals, rock and other materials are transported in mine trolleys, which move along rail tracks with the help of locomotives.

The rail track consists of a ballast layer on the working soil, sleepers, rails and their connections.

The ballast layer consists of crushed stone and serves as a shock-absorbing base.

Sleepers serve to connect rail tracks to a common track, and there are metal, wooden and reinforced concrete.

Track width is the distance between the inner edges of the rail heads. Standard track width 600-900mm.

The main characteristic of the rail- weight 1 meter. Apply rails weighing 24.33.48 kg/ m

Mining trolleys are divided into the following types:

• Freight trolleys;
• Human carts;
• Trolleys and platforms for transportation of materials and equipment;
• Special purpose (repair, track measuring)

According to the method of unloading, the trolleys are divided into:

• Flat-body trolleys (unloaded by overturning) VG;
• Self-unloading trolleys with a folding bottom - VD type;
• Self-unloading trolleys with a folding side WB (UVB);

Modern trolleys have a capacity of 0.8 - 3.3 m 3 , the most common capacity is 2.4 or 3.3m 3 .

Locomotives by type of energy are divided into:

• Contact electric locomotives;
• Battery electric locomotives;
• Diesel carts;
• Hydro wagons;
• Air carts (pneumatic locomotives).
• Electric locomotives are the most widely used. (diesel carts on sh."Osinnikovskaya aya").

When using contact electric locomotives, electricity is supplied through the conductor of the contact network (trawl) and the current-carrying rail. The electric locomotive is equipped with a DC motor with a voltage of 250 V. The mass of contact electric locomotives is 7, 10, 14, 20, 25 tons. The speed is up to 25 km/h.

Contact electric locomotives are used in non-gas mines, as well as in the fresh stream of mines I-II categories.

Battery electric locomotives receive electricity from batteries. Coupling weight 7, 8, 14 tons, speed up to 14 km/h.

Transportation by self-propelled trolleys

The self-propelled trolley moves along the working soil on 4 or 6 wheels with pneumatic tires. El energy is supplied by cable. Diesel-powered trolleys are also used. To speed up the process of unloading and loading, a scraper conveyor is built into the bottoms of some trolleys.

Hydraulic and pneumatic transport

It is used for transporting coal and supplying backfill material.

Auxiliary transport

For the delivery of people, materials and equipment, the following are used:

• Locomotive rollback.
• Specially equipped belt conveyors and idle belts of conventional belt conveyors.
• Rollback with end rope.
• Rollback with an endless rope.
• Monorail roads.

Mine lifting

Shaft lifting installations are used to provide transport links with transport horizons.

The main lifting unit is designed to bring the mined PI to the surface.

Auxiliary lifting unit– for descent-ascent of people, materials, equipment, issuance of waste rock.

Human lifting installations– designed exclusively for lowering and raising people.

The following elements belong to the mine hoist:

• lifting machines;
• Lifting vessels (skips, cages);
• lifting ropes;
• Necessary reinforcement of the barrel (executions, guides, grips);
• Loading and unloading devices;

mine pile driver is installed directly above the barrel and serves to accommodate the guide pulleys.

lifting machineis installed at some distance from the shaft and serves to move the vessels by winding traction ropes onto the drive drum, to which these vessels are suspended.

lifting ropesare made of high-strength steel wires wound in a special way on a hemp or steel core. The Ø of the ropes is determined by calculation and is 18.5 - 65mm, the diameter of the steel wires is 1.2 - 2.8mm. Ropes of lifting installations for lowering - lifting people must have a safety margin of at least 9, for cargo lifts - at least 6.5.

In vertical shafts, lifting vessels are:

• Mine skips;
• Tipping stands;
• Non tipping stands;

If one vessel is suspended from the lifting machine, then the lifting is called single-cell (one skip), if two - two cages or two skips.

To direct the movement of the lifting vessel, special structures are hung in the shaft - conductors , which are attached to transverse struts, executions.lifting vesselshave a special supports enclosing conductors.

Lifting vessels have special braking devices called parachutes . When the rope is loosened or broken, parachutes are captured by guides or specials. brake ropes, keeping the vessel from falling.

Along with the purpose, lifts are classified according to the type of lifting vessels into: Lifts with non-tipping stands; Lifts with tipping stands; Skip lifts.

Tipping stands different from non-tipping the fact that the loaded trolleys on the surface do not roll out of the cage, but are unloaded into the receiving hopper when the cage is turned (overturned).

In large modern mines, the main, as a rule, is the skip lift.

With skip liftthe rock mass is reloaded into a special vessel called a skip. On the surface, the skip is unloaded by capsizing or through the bottom.

Skip consists from frame and body. For skips unloading through the bottom, the body is rigidly connected to the frame. For tipping skips, the body is hingedly connected to the frame and is unloaded by turning around the axis when the skip enters the unloading curves.

Technological complex on the surface of the mine

mine pile driver , metal or reinforced concrete, is constructed directly above the mouth of the trunk. The height of conventional headframes is 15 - 30m, tower headframes - up to 100m.

Conventional headframes are used to accommodate guide pulleys and conductors, fastening unloading curves and landing devices.

Tower headframes made of concrete or reinforced concrete in the upper part have a machine room for a lifting machine with a friction pulley.

Pithead- directly adjacent to the pile driver and serves to ensure the operation of the mine hoist. The sorting building is arranged for preliminary selection of rock and sorting of coal by size. Instead of sorting, a processing plant may be located on the territory of the mine.

Overpasses, conveyor galleries and bridges– facilities for laying narrow potash rail tracks and installation of belt conveyors. Depending on the purpose, these structures can be open or closed, horizontal or inclined.

Receiving and loading bunkersare metal or concrete structures designed for short-term storage of minerals.

rock heap - a surface area reserved for the storage of waste rock.

Mine ventilation system

Ventilation systemmines - a set of mine workings of fan installations and ventilation structures in the mine and on the surface, providing stable and efficient ventilation.

The ventilation method is determined by how the fan works:

Suction - suction method.

For injection - injection method.

One for suction, the other for discharge.- combined method.

Ventilation schemedetermined by the direction of movement of the ventilation stream.

central schemeprovides for the supply of a fresh stream of air and the removal of the outgoing air is carried out along the closely located main opening workings.

flank scheme provides for the supply of fresh and removal of the outgoing jet through the main opening workings located in different parts of the mine field.

Combined schemeis a combination of the two described above.

Ventilation systemmay be single or sectional.

With sectional - the mine is divided into separate separately ventilated sections.

With a single schemethe mine is ventilated without division into separate sections (sections).

Mine fan installations

Mine fan installation serves for continuous supply of fresh air into the mine and consists of: Working fan; Backup fan; ventilation ducts; Devices for measuring the direction of air movement; electric motors; Control and recording equipment; Ventilation building. Mine fan installations have a capacity of 3 - 5 to 20 - 25 thousand. m 3 min.

Depression (compression) fanis the difference between the pressure at the fan exhaust and the atmospheric pressure.

Modern fans create a pressure (depression) of 470 - 700 daPa.

Mine fan structures

By purpose, fan devices are divided into: Blind jumpers for isolation of workings; Ventilation sluices with doors, windows or methods to regulate air in mine workings; Crossings (air bridges) - ventilation structures for separating air jets in intersecting workings;

Air distribution and mine atmosphere monitoring

Control over the air distribution and the state of the mine atmosphere is carried out by the mine's engineering and technical staff and employees of the ventilation and safety department (VTB).

To control the composition of the atmosphere, mine interferometers SHI10, SHI11, gas detectors of the GH type, devices of the type"Signal". Anemometers of the ASO - 3, MS - 13 and APR - 2 types are used to control the air flow.

Permissible content CH 4 and CO 2

	CH 4%	CO2%
Ref. From a clearing or dead-end development Ref. Wings (mines) The incoming jet into the workings and into the faces of dead-end workings
	Rock physics as a science basic concepts and definitions 2. Rock physics as a science basic concepts and definitions Rock physics petrophysics is one of the main disciplines of exploration geophysics most closely related to matter physics and petrology. Of the many physical properties of rocks, petrophysics mainly studies the properties that create physical fields that can be measured by geophysical methods.
9132.		MAIN PROPERTIES OF ROCKS	21.78KB
	Classification of properties of rocks. The number of physical properties of rocks manifested in their interaction with other objects and phenomena of the material world can be arbitrarily large. Geomechanics requires knowledge primarily of mechanical and density properties, but at the same time, some other properties may be of interest, the indicators of which quite clearly reflect the state of the rocks or clearly correlate with the stresses in the rock mass and therefore can be used to assess...
1639.		GEOMECHANICAL SUPPLY FOR MINING	13.98MB
	Rocks with a strength of 3050 MPa under the influence of mining operations, when the stress increases by 23 times compared to the stresses in the massif untouched by mine workings, lose their strength. Such a phenomenon was not observed at a shallow depth, that is, we seem to be working in conditions of less durable rocks. In connection with the predicted increase in rock displacement into the working by a factor of three at a depth of 1000 m compared to a depth of 500 m, a significant increase in the volume of repair work should be expected. Which of the above do we know what's new in the course...
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9127.		METHODS FOR DETERMINING ROCK PROPERTIES	299.19KB
	Taking into account the previously stated ideas about the hierarchical block structure of rocks and massifs and in principle two possible ways to determine the various characteristics of the integral and differential, let us consider in more detail the principles for determining individual properties. Thus, in order to determine the integral density characteristics of a massif represented by various petrographic varieties of rocks and various types of structural heterogeneities, in principle, it is sufficient to determine these ...
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2554.		ROCK MOVEMENT DURING UNDERGROUND DEVELOPMENT	384.33KB
	Carrying out mining operations violates the natural state of rock massifs, rocks, as a result of which the latter get out of balance, deform and move. Typically, these processes capture the entire thickness of the massif, including the surface. Rocks on the earth's surface also undergo deformation and displacement.
9130.		NATURAL STRESS FIELD OF A ROCK MASS	150.18KB
	Rock masses as objects of study in geomechanics have one very significant feature in comparison with objects considered in mechanics in general or in the mechanics of solid deformable bodies in particular. Tectonic stress fields are currently associated with the first of these types of movements. The data of direct measurements and observations in our country and abroad testify to the confinement of high horizontal stresses to zones of tectonic uplifts of the earth's crust...
9113.		METHODS OF PROTECTION OF OBJECTS AND CONSTRUCTIONS IN THE ZONE OF INFLUENCE OF MINING OPERATIONS	66.14KB
	To protect objects and structures from the harmful effects of underground mining and to prevent water breakthroughs into mine workings, various protection measures are used, which can be conditionally divided into four groups: preventive mining engineering complex. Preventive measures have the main purpose of preventing or reducing the harmful effects of mining. They must be carried out both during the preparation of projects for the development of deposits and ...
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1. The choice of shape and calculation of the dimensions of the cross section of the mine

When carrying out workings, two types of mining operations are distinguished: main and auxiliary.

The main mining operations are those that are performed at the working face and relate directly to the driving and fixing of the working.

Auxiliary operations are those that provide normal conditions for performing the main tunneling operations.

The cross-sectional area of ​​the working depends on the purpose and dimensions of the equipment located in it. There are cross-sectional areas of horizontal workings in the light, in the rough and after sinking. The clear area is determined by the dimensions of the working to the lining minus the areas occupied by the ballast layer and the gangway in the section of the working. The rough area is the design area in the penetration. When determining this area, the areas occupied by the support, ballast layer, gangway and tightening (with frame supports installed in a run-up) are added to the clear area. The actual area, which is obtained as a result of working out, usually exceeds the design area by 3-5% or more.

The cross-sectional dimensions (width and height) of haulage workings depend on the overall dimensions of haulage trolleys and electric locomotives, on the rail tracks of the method of movement of workers along the workings and the amount of air supplied for ventilation.

If there are rail tracks in the workings for the movement of people, a path (passage) with a width of at least 700 mm is provided, which must be maintained at a height of 1800 mm from the level of the ladder (ballast layer).

Based on specific conditions: f =16; stability - average; working life - 16 years, we choose the vaulted shape of the working, sprayed with concrete fastening

1. Calculate the cross section of the working height.

a. The height of the structure of the rail track h 0, mm

h 0 \u003d h b + h w + h p + h p, mm;

Where: h 0 - the height of the upper structure of the working path, is selected with the norms providing for the EPB, mm;

h b - height of the ballast layer, mm;

h p - the height of the lining under the rail, mm;

h p - rail track height, mm;

h 0 \u003d 100 + 420 + 20 + 135 \u003d 375 (mm).

2. Rolling stock height h, mm

3. The height of the straight-wall section of the mine.

h 1 = 1800 (mm).

4. Height of working in the clear.

h 2 \u003d h 1 + h b + 1 / 3h w, mm;

h 2 \u003d 1800 + 135 + 20 + 1/3 * 120 \u003d 1995 (mm).

Where: h 1 - the height of the straight-wall section of the mine, mm;

h b - the height of the ballast layer, is selected with the standards providing for the EPB, mm;

h w - sleeper beam height, mm;

5. Working height in black.

h 3 \u003d h 0 + h 1, mm;

h 3 \u003d 375 + 1800 \u003d 2175 (mm).

6. Clear vault height.

h h \u003d 1/3 * V, mm;

h h \u003d 1/3 * 2250 \u003d 750 (mm).

7. The height of the vaulted ceiling in black.

h 5 \u003d h h + T cr. , mm;

h 5 \u003d 750 + 50 \u003d 800 (mm).

8. The clear width of the working is calculated.

B= n+A+m, mm;

H=200+1350+700=2250 (mm).

Where: B - clear working width, mm;

n is the gap between the support and the rolling stock, mm;

A - rolling stock width, mm;

m - free passage for people, mm;

9. Working width in draft.

B 1 \u003d B + 2 * T cr. , mm;

B 1 \u003d 2250 + 100 \u003d 2350 (mm).

10. Clear cross-sectional area.

S St. \u003d B * (h 2 + 0.26 * B)

S St. \u003d 2250 * (2745 + 0.26 * 2250) \u003d 7.4 m 2

11. Cross-sectional area in blacker.

S black \u003d B 1 * (h 3 + 0.26 * B 1)

S black \u003d 2350 * (2960 + 0.26 * 2350) \u003d 8.3 m 2

12. The speed of the air flow.

V = Q air / S c in, m / s;

V \u003d 18 / 7.4 \u003d 2.4 m / s;

Where: V is the speed of movement of the ventilation jet along the working, regulated by safety rules, m/s;

Q air - the amount of air passing through the working, m 3 / s;

S c in - the cross-sectional area of ​​​​the workings in the light, m ​​2;

Since V \u003d 2.4 m / s, then 0.25? V? 8.0 satisfies the requirements of the EPB, therefore, this section is calculated correctly.

13. Section in the penetration.

S pr \u003d 1.03 * S black, m

S pr \u003d 1.03 * 8.3 \u003d 8.7 (m)

Depending on the physical and technical properties of the rocks, the service life of the working, the possible impact of cleaning operations, the cross-sectional shape, materials and type of support are selected ...

Selection and justification of technology, mechanization and organization of human walking

For this production, we get special. profile SPV-17. Choose special. profile by economic factor. For special The SVP-17 profile has the following characteristics: = 18774, which corresponds to the interval = 18700 - 20700. W(1) = 50.3 P(1) = 21.73 Table 2...

Choice of protection method and type of mine working support

Figure 2.1 shows the location of the working relative to the rocks enclosing the coal seam. From the point of view of working protection, it is certainly beneficial to use a roadheader for this working...

Hydraulic calculation of the unit of hydraulic structures

Determining the dimensions of the cross section is reduced to determining the width along the bottom and the depth of filling according to the specified parameters (flow rate Q, slope i, roughness coefficients n and slopes m)...

double track crosscut

When developing a project for excavation, the issue of choosing the shape and dimensions of the cross section is the most important. For horizontal exploration workings, rectangular-vaulted and trapezoidal cross-sectional shapes are standard ...

Organization and conduct of mining and exploration works

Since the task does not specify the selection of a technological sample, we will bring Sm to the nearest standard one in accordance with GOST: 1) based on the fact that the depth of the pit is 30 m ...

Underground mining

We determine the cross section of the main vertical shaft according to the formulas and refine it according to table 4.2: SВ = 23.4+3.6 AG, (5) where AG is the annual production capacity of the mine, million tons. SB = 23.4 + 3.6 1 .4 = 28.44 m2...

Mining breaks the stable stress state of rocks. Zones of high and low stresses are formed around the working contour. To prevent the collapse of rocks, the working is fixed ...

Mining development

4.1 Calculation of the cross-sectional area of ​​a trapezoid-shaped mine Determination of the dimensions of the mine in the light. Width of a single-track working at the level of the edge of the rolling stock: B= m + A + n1, m Where: m = 0...

Since the working life of the bremsberg has a service life of 14 years, it is recommended to carry out the working of an arched cross-section, fasten it with a frame arch support and reinforced concrete tightening ...

Technological project for horizontal underground mine workings

The cross-sectional shape of the working is selected taking into account the design and material of the support, which, in turn, are determined by the stability of the rocks in the sides and roof of the working...

Technology of adit development in hard rocks

1. The amount of air that should pass through the mine during its operation is determined: (1)

For open exploratory workings, justify the method of penetration, the equipment used and, in accordance with the angle of repose of rocks, select and justify the shape and dimensions of the cross section, taking into account the design depth of the working.

For underground mining and exploration workings, justify the method of penetration and the corresponding mining equipment, select and justify the shape and dimensions of the cross section of the working in the clear.

Depending on the physical and mechanical properties of rocks, as well as on the basis of the dimensions of transport and technological equipment (electric locomotives, trolleys, loading machines), taking into account the clearances provided for by the safety rules (PB) during geological exploration, the dimensions of the cross-section of mine workings in the clear are determined . The dimensions of the workings in the penetration are determined taking into account the thickness of the lining and puffs, as well as the height of the track device (ballast, sleeper, rails).

Mining workings can be carried out with and without fastening. Wood, concrete, reinforced concrete, metal and other materials are used as fastening material. The shape of the section can be: rectangular, trapezoidal, vaulted, round, elliptical.

Horizontal and inclined exploration workings have, as a rule, a short service life, therefore, the main type of lining is wood, the cross-sectional shape is trapezoidal. When driving without fastening, the cross-sectional shape is rectangular-vaulted.

For a trapezoidal cross section of a working with rail transport ( rice. one) it is recommended to calculate the cross-sectional area of ​​the working in the following sequence.

According to the dimensions (width and height) of the electric locomotive or trolley used (with manual haulage), the clear width of a single-track working is determined at the level of the edge of the rolling stock:

B = m + A + n`

and the width of the double-track working:

B = m + 2A + p + n`

m- the size of the gap at the level of the edge of the rolling stock, mm(assumed to be 200 - 250 mm);

p- the gap between the compositions, mm (200mm);

n`- the size of the passage for people at the level of the edge of the rolling stock, mm:

n` = n + *ctg ;

n- the size of the passage at a height of 1800 mm from the level of the ballast layer, equal to at least 700 mm;

h- the height of the electric locomotive (trolley) from the rail head, mm;

h a- the height of the superstructure of the track from the ballast layer to the rail head, equal to 160 mm;

83 0 - the angle of inclination of the racks, taken according to GOST 22940-85 for exploration work.

The height of the working from the rail head to the top rack in the case of the use of contact electric locomotives (before the draft of the support):

h 1 \u003d h kp. + 200 + 100,

h kp.– contact wire suspension height (not less than 1800 mm);

200mm– clearance between the contact wire and the support;

100mm- the value of the possible settlement of the support under the action of rock pressure.

For other modes of transport, the height h1 determined by graphical construction, taking into account the gap C between transport equipment and ventilation pipeline: when transported by battery electric locomotives 250 mm, with manual rollback - 200 mm.

When transporting by battery electric locomotive:

h 1 \u003d h + d t + 250 + 100,

where h- locomotive height, mm;

d t- ventilation duct diameter, mm.

Height h1 in the general case, it should not be less than the height of the loading machine with the bucket raised (for PPN-1s this height is 2250 mm) minus the height of the ballast layer, i.e. h 1 2250 mm.

Clear working width along the ballast layer:

l 2 \u003d B + 2 (h + h a) * ctg ;

Clear working width along the roof:

l 1 \u003d B - 2 (h 1 - h) * ctg ;

The height of the working from the ballast layer to the lining after settlement:

h 2 \u003d h 1 + h a;

Cross-sectional area of ​​the working in the clear after settlement:

S St \u003d 0.5 (l 1 + l 2) * h 2;

The width of the working out in the rough on the roof (when fastening side by side with tightening the sides):

l 3 \u003d l 1 + 2d,

where d- support post diameter (not less than 160 mm).

Width of working out on the soil rough when fastening side by side with tightening of the sides:

l 4 \u003d B + ,

where h in= 320mm- height from the working soil to the rail head:

h in = h a + h b,

where h b - ballast height.

Working height from soil to support (before draft):

h 3 ` = h 3 + 100,

where . h 3- the height of the working from the soil to the top (after draft).

The height of the working in the rough to the draft in the presence of tightening:

h 4 ` =h 3 ` + d + 50,

where d- diameter of the fastening wood, mm;

50mm- tightening thickness.

Working height after settlement:

h 4 \u003d h 4 ` - 100

The cross-sectional area of ​​the working in the rough before draft:

S 4 \u003d 0.5 (l 3 + l 4) * h 4 `

Vertical draft equal to 100 mm, is allowed only with wooden support.

In the workings, the laying of wooden sleepers and the laying of the track from the rails are used. R24 for trolleys up to 2 m 3. When carrying out exploration workings, trolleys are used VO-0.8; VG-0.7 and VG-1,2 capacity respectively 0.8; 0.7; 1.2 m. When manually rolling with trolleys VO-0.8 and VG-0.7, as well as AK-2u electric locomotives, rails are used R18. The sleepers are laid in a ballast layer with a thickness of 160 mm, immersing them in 2/3 of its thickness.

With a rectangular-vaulted shape, the clear height of the working is the sum of the wall height from the level of the ballast layer and from the height of the arch ( rice. 2).

Rough working height H is defined as the clear height plus the thickness of the lining in the vault with a monolithic concrete lining or plus 50 mm with sprayed concrete, anchor (rod) and combined supports. Wall height from the level of the rail head to the heel of the vault h1 when transported by battery electric locomotives, it is determined depending on the height of the electric locomotive. The height of the workings during transportation by contact electric locomotives must satisfy the conditions under which minimum clearances are provided between the electric locomotive (trolley) and the support, as well as between the current collector and the support.

The height of the vertical wall from the level of the tapa to the heel of the vault h 2 = 1800mm. vault height h 0 take depending on the coefficient of rock strength according to the scale of M.M. Protodyakonova.

For monolithic concrete lining with strength coefficient f =3:9, h 0 = B/3.

For sprayed-concrete and anchor lining and in workings without support f 12 ,h 0 \u003d B / 3, and when f 12, h 0 \u003d B / 4.

The curve of the three-center (box) arch is formed by three arcs: axial - R and two side r. The radii of the vault, depending on its height:

vault height	h 0	B/3	B/4
Radius of axial arc	R	0,692	0,905
side arc radius	r	0,262	0,173

Design working width B1 for concrete lining it consists of the clear width of the working and twice the thickness of the lining, and for sprayed concrete, anchor and combined lining - from the clear width of the working plus 100 mm.

Single track clearing width:

B=m+A+n

Clear width of a double-track working:

B=m+2A+p+n,

where n= 700mm; p= 200mm.

The height of the vertical wall of the working from the rail head:

h 1 \u003d h 2 - h a \u003d 1800 - 160 \u003d 1640 mm.

Rough working width with sprayed concrete and anchor lining:

B1=B+2 = B + 100,

where = 50mm- the thickness of the support, taken in the calculation.

Cross-sectional area of ​​the working in the clear at the height of the arch h 0 = B/3:

S St. \u003d B (h 2 + 0.26B),

at h 0 = B/4: S sv \u003d B (h 2 + 0.175B),

where h 2 = 1800mm - the height of the vertical wall from the level of the ladder (ballast layer).

Wall height from the working soil:

h 3 \u003d h 2 + h b \u003d h 1 + h B.

Clear output parameter at h 0 \u003d B / 3:

P B = 2h 2 + 2.33B,

at h 0 \u003d B / 4: .P B = 2h 2 +2219B

The cross-sectional area of ​​the working in the rough with sprayed concrete, anchor, combined lining with h 0 \u003d B / 3:

S h. \u003d B 1 (h 3 + 0.26B 1),

at h 0 \u003d B / 4: S h. \u003d B 1 (h 3 + 0.175B 1).

After determining the cross-sectional area, we take according to GOST 22940-85 the nearest standard section and write out its dimensions for further calculations. According to this standard, only the cross-sectional area of ​​​​the working in the clear is determined, and the cross-sectional area is set in rough, depending on the accepted sectional shape, type and thickness of the support according to the above formulas.

Table 1 typical sections and basic equipment used in the calculation of the clear section, as well as the dimensions of the base vehicles are given.

The pits are conditionally divided into shallow (up to 5 m), medium (5 - 10) and deep (up to 40 m). The depth of the pits depends on the stage of exploration and geological conditions. Depending on the physical and mechanical properties of the rocks, the method of sinking and the design of the lining, the pits are round and rectangular in shape. As the depth of the pit increases, the clear cross-sectional area increases. Holes up to 10 deep m usually have one compartment, and at a depth of up to 20 m may have two compartments. Typical sections ( GOST 41-02-206-81), drilling of pits with a clear cross-sectional area from 0.8 to 4 m 3 and geometric dimensions (Table 2).

FEDERAL FISHING AGENCY

FEDERAL STATE EDUCATIONAL INSTITUTION

HIGHER EDUCATION

“MURMANSK STATE TECHNICAL UNIVERSITY”

Apatity branch

Department of Mining

MINING

Guidelines for the implementation of the course project

for students of the specialty

130400 "Mining"

GENERAL ORGANIZATIONAL AND METHODOLOGICAL INSTRUCTIONS

The course project is the final stage in the study of the discipline "Conducting mine workings" and should contribute to the consolidation of theoretical knowledge in the specialty.

The purpose of the course project is to study the technical, technological and organizational issues of driving the projected development.

When performing the course work, the technical, technological and organizational issues of driving the projected development should be worked out, and the decisions made should ensure the safety of the work.

When working on a term paper, it is necessary to use educational literature, unified mining safety rules (EPB), as well as materials from domestic and foreign scientific journals.

The explanatory note of the course work should contain all the necessary calculations and justifications for the decisions made, sketches and diagrams (ventilation scheme, design and penetration sections, hole layout, charge design, work organization schedule).

The sequence of presentation of the material in the explanatory note must comply with the guidelines.

1. WORKING CONDITIONS

Working conditions are understood as hydrogeological data and mining and technical conditions in which the working will be carried out. In this section, if they are not specified, the physical and mechanical properties of the rocks should be described in terms of their stability, strength, conditions of occurrence and inflow of water into the workings during excavation.

2. METHODS OF DRIVING AND MECHANIZATION OF WORKS

The applied method of penetration should be the most rational in terms of work safety and mechanization of production processes.

When choosing a tunneling method and means of mechanized work, it is preferable to use equipment complexes that provide mechanization of the tunneling work cycle processes to a greater extent.

3. DETERMINATION OF THE DIMENSIONS OF THE CROSS-SECTION OF THE WORKING AND THE CALCULATION OF THE SUPPORT.

Support calculation.

The load on the support, related to 1 m 2 of working, with a uniformly distributed disturbed zone, is determined by the formula:

Kgf/m 2 (3.29)

where: ρ – volumetric weight of rock, kg/m 3 ;

l n– dimensions of the disturbed zone, m.

The value of the disturbed zone is determined by the formulas:

a) for workings outside the zone of influence of clearing operations:

b) for inlet and delivery workings:

where: I T– intensity of a gently dipping small-block system of cracks, pieces/m. linear (Table 1);

K C– coefficient of working condition (assumed equal to 1).

Table 1

table 2

Table 3

Specific adhesion of the rod to concrete and concrete column to rock, kgf / cm 2

Strength indicators	Material name	Fixing solution on cement M-400 at the age of 28 days. with the composition of the mixture C:P	Mortar on aluminous cement M-400 aged
3 days with the composition of the mixture C:P	12 h at C:P
1:1	1:2	1:3	1:1	1:2	1:3	1:1
	Steel of a periodic profile
steel smooth round
	Concrete column with apatite ore
Concrete column with oxidized ore
Concrete column with waste rocks of the lying side

The distance between the rods with a square grid of their location is taken from the conditions for preventing delamination and collapse of rocks under the action of their own weight within the fixed thickness according to the formula:

, m (3.40)

where: K zap– safety factor;

m– coefficient of operating conditions of the rod support (1 - for rods with pre-tensioning; 2 - for rods without pre-tensioning).

Table 4.1

Table 4.2

BB characteristic

Name of explosive	Density of explosives in cartridges, g / cm 3	Working capacity, cm 3	Detonation speed, km/s	Type of packaging
BB,used in the faces that are not hazardous in terms of gas or dust
Ammonite 6ZhV	1,0–1,2	360–380	3,6–4,8	Cartridges with a diameter of 32, 60, 90 mm
Ammonal-200	0,95–1,1	400–430	4.2–4,6	Cartridges with a diameter of 32mm
Ammonal M-10	0,95–1,2		4,2–4,6	Same
Ammonal rock №3	1,0–1,1	450–470	4,2–4,6	Cartridges with a diameter of 45, 60, 90 mm
Ammonal rock №1	1,43–1,58	450–480	6,0–6,5	Cartridges with a diameter of 36, 45, 60, 90 mm
Detonit M	0,92–1,2	450–500	40–60	Cartridges with a diameter of 28, 32, 36 mm
BB,used in the faces hazardous for gas or dust
Ammonite AP-5ZhV	1,0–1,15	320–330	3,6–4,6	Cartridges with a diameter of 36 mm
Ammonite T-19	1,05–1,2	267–280	3,6–4,3	Same
Ammonite PZhV-20	1,05–1,2	265–280	3,5–4,0	Same

In the practice of tunneling, electric blasting with the help of instantaneous, short-delayed and delayed electric detonators, as well as non-electric blasting systems (Nonel, SINV, etc.) has become most widespread.

Table 4.3

Kzsh values ​​for horizontal workings

Hole diameter. The diameter of the holes is determined based on the diameter of the explosive cartridges and the required gap between the wall of the hole and the explosive cartridges, which makes it possible to send the explosive cartridges into the hole without effort. Cutters and crowns wear out during drilling and sharpening, as a result of which their diameter decreases. Therefore, the initial diameter of incisors and crowns is used somewhat larger than required, and it is 41 - 43 mm for explosive cartridges with a diameter of 36 - 37 mm and 51 - 53 for explosive cartridges with a diameter of 44 - 45 mm. The borehole diameter should be 5–6 mm when the firing cartridge is located first from the hole mouth, and 7–8 mm when the firing cartridge is located not first from the hole mouth.

An increase in the diameter of the holes leads to an increase in the explosive charge placed in them, and consequently, the number of holes decreases. At the same time, an increase in the diameter of the holes leads to a deterioration in the delineation of the mine working, excessive destruction of the rock beyond the design contour, and also negatively affects the pace of drilling - the drilling speed decreases.

With an increase in the diameter of the charge of holes on the contour of the working, the zone of destruction of the massif increases and, consequently, the stability of the rocks decreases. Therefore, with a decrease in the cross-section of the mine, it is more expedient to use small-diameter holes. With a decrease in the cross section of the working and an increase in the strength of the rocks, the diameter of the holes and charges, other things being equal, should decrease. Since currently produced explosives (detonites) are capable of detonating at high speed in cartridges of small diameter (20 - 22 mm), it is obvious that it is expedient to use holes with a reduced diameter. And when using explosives with a low detonation velocity such as ammonites, it is advisable to place cartridges with a diameter of 32–40 mm in the boreholes.

Hole depth. Hole depth is a tunneling operation parameter that determines the scope of the main operations in the tunneling cycle and the speed of the development.

When choosing the depth of holes, the area and shape of the bottomhole, the properties of the blasted rocks, the performance of the explosives used, the type of drilling equipment, the required advancement of the bottomhole for the explosion, etc. are taken into account. integer number of driving cycles.

With a small (1 - 1.5 m) depth of holes, the time of auxiliary work related to 1 m of bottom advance increases (ventilation, preparatory and final operations when drilling holes and loading rock, loading and blasting explosives, etc.).

With a large (3.5 - 4.5 m) depth of holes, the rate of drilling of holes decreases and, ultimately, the relative duration of 1 m of mining increases.

In addition, when choosing the depth of the hole, it should be taken into account that when blasting at great depths from the earth's surface, where the blasted rocks are compressed from all sides by rock pressure, the destructive effect of the explosion is significantly reduced.

The depth of the holes is determined on the basis of a given technical penetration rate, the number and productivity of mining equipment, or according to production rates.

Knowing the given rate of penetration, it is possible to calculate the depth of the hole:

where: ν – specified penetration rate, m/month;

t c - cycle duration, h;

n s is the number of working days in a month;

n h - the number of working hours per day;

η is the hole utilization factor (KSH).

Drillhole utilization rate. The ratio of the use of holes is the ratio of the used depth of the hole to the original depth. During the explosion of explosive charges in boreholes, the rock is not torn off to the entire depth of the boreholes, part of the borehole is not used in depth and remains in the array of the hearth, which is commonly called a glass.

In order to determine the KIS for the entire set of holes, it is necessary to measure the depth of all holes and determine the average depth of the hole. After the explosion of the charges, it is necessary to measure the depth of all the glasses and determine the average depth of the glass, from which you can find the average value of the KIS. Therefore, in order to determine the average value of the KIS, it is necessary to divide the value of the average bottom advance by the average depth of the hole.

where: l z - the length of the charge of the hole;

l w is the depth of the hole.

If the bottom advance per cycle is given, then the average depth of the hole can be determined by dividing the bottom advance per cycle by the average value of the FIR.

The value of KIS depends on the strength, fracturing and layering of the blasted rocks, the face area, the number of open surfaces in the blasted massif, the efficiency of the explosive, the depth of the holes, the quality of the hole driving, the sequence of blasting charges and other factors. With the correct determination of all parameters, strict implementation of the technology of blasting, the value of the KIS must be at least the following values.

Table 4.4.

Table 4.5

Numerical values ​​of the exponent γ

 cc, kg/m 3
, units	1.843	1.892	1.940	1.987	2.033	2.125	2.214	2.301

 вв - volumetric weight of explosives in charge, kg / m 3

The distance between the contour charges is determined by the formula (m):

(4.6)

where: K 0- numerical coefficient taking into account the interaction of adjacent contour charges and energy losses due to the expansion of detonation products in the volume of the hole, units;

L zk- length of contour holes driving (determined according to the table), m;

L to- length of contour holes, m.

Table 4.6

The value of the numerical coefficient K 0

Table 4.7

Reduced length of stemming of contour charges L zk / S vyr

Coefficient	Linear loading density of contour holes P to, kg/m
rock fortresses	0.4	0.5	0.6
4-6	0.110-0.097	0.121-0.110	0.129-0.119
7-9	0.092-0.082	0.106-0.097	0.115-0.108
10-14	0.077-0.061	0.093-0.079	0.105-0.092
15-18	0.057-0.046	0.076-0.067	0.089-0.081
19-20	0.042-0.039	0.064-0.061	0.079-0.076

The coefficient of convergence of contour holes is determined by the formula:

(4.7)

At  cc\u003d 900 - 1100 kg / m 3 this formula can be used in the following form:

(4.8)

Accordingly, the line of least resistance of contour holes is determined by the formula (m):

The number of contour holes is determined by the formula (pieces):

(4.10)

where: P- full perimeter of the working face, m;

AT- working width at soil level, m

The area of ​​the part of the face that falls on the contour row is (m 2):

(4.11)

To improve the quality of rock working at the level of the end parts of the contour holes, an additional charge with a weight equal to (kg) should be placed in the bottom of the latter:

The number of explosives per contour breaking is determined by the formula (kg):

With preliminary contouring specific consumption of explosives is determined taking into account the depth of work H(m) according to the formula (kg / m 3):

(4.14)

At the same time, it should be borne in mind that with a decrease in the depth of work, the value q to should not be less than the value determined by formula (4.3).

The distance between the contour holes is calculated by the formula (4.6), while the value L zk determined according to the table (4.8).

Table 4.8

Reduced length of contour charges during preliminary contouring of the working

Coefficient	Depth of work H, m
fortresses	less than 100	100-200	200-400	400-600
rocks, f	Linear loading density of contour holes P k, kg/m
	0.4	0.5	0.6	0.4	0.5	0.6	0.4	0.5	0.6	0.4	0.5	0.6
4-6	0.109	0.120	0.128	0.120	0.130	0.137	0.132	0.139	0.145	0.142	0.148	0.152
7-9	0.093	0.106	0.116	0.106	0.117	0.125	0.118	0.128	0.135	0.130	0.138	0.144
10-14	0.074	0.091	0.103	0.089	0.103	0.113	0.104	0.115	0.124	0.118	0.127	0.135
15-18	0.057	0.077	0.090	0.073	0.090	0.101	0.089	0.103	0.113	0.105	0.117	0.125
19-20	0.046	0.067	0.082	0.062	0.081	0.093	0.080	0.096	0.106	0.097	0.110	0.119

The weight of the additional charge in the bottom of contour holes is determined by the formula (kg):

Number of contour holes N to and consumption of explosives for contouring the working Q to calculated by formulas. (4.10) and (4.13)

After determining the parameters of contour blasting, they proceed to the calculation of the parameters of loading and placement of cutting and breaking holes. The calculation is based on the value of the specific consumption of explosives for rock crushing within the drilled volume.

During subsequent contouring, the bottomhole core is broken in the stressed state of the surrounding rock mass, which leads to the need to increase energy consumption for rock crushing in the drilled massif. In this case, you should first determine the characteristic value of the length of the drilling holes, taking into account the degree of such influence (m):

(4.16)

Depending on the actual length of the drilling holes L reb, which, as a rule, is determined by the organization of work and the capabilities of drilling equipment, the value of the specific consumption of explosives for crushing is calculated by the formulas (kg / m 3):

At L reb  L  :

(4.17)

At L reb  L  :

(4.18)

where: e cc- conversion factor, taking into account the type and density of the explosive used.

Table 4.9

The value of the coefficients е вв

During the preliminary contouring of the working, the breaking of the main rock volume is carried out under conditions of partial unloading, which makes it possible with the length of the breaking holes L reb  L  reduce the value of the specific consumption of explosives to the value determined by formula (4.17)

After determining the specific consumption of explosives, the parameters for placing holes in a straight cut are calculated. The value of the specific consumption of explosives in the cut is determined taking into account the overall efficiency of rock breaking in the working face:

(4.19)

where: N vr- number of cutting holes, units;

R BP- linear density of their loading, kg/m;

L vr- length of cutting holes, m;

L zb- stemming length, m.

Absolute value L zb determined according to the tables below, followed by division by e cc, which makes it possible to take into account the type of explosive used.

Table 4.10

during the subsequent delineation of the mine working

Coefficient	Depth of work H, m
fortresses		100 - 200	200 - 400	400 - 600
breeds
4-6	0.145	0.151	0.156	0.162
7-9	0.137	0.143	0.149	0.156
10-14	0.128	0.135	0.142	0.149
15-18	0.119	0.127	0.135	0.143
19-20	0.113	0.122	0.130	0.139

Table 4.11

Reduced length of driving of jackholes in the preliminary contouring of a mine working

Rock strength coefficient	L zb / S vyr
4-6	0.145-0.139
7-9	0.136-0.131
10-14	0.129-0.121
15-18	0.119-0.113
19-20	0.111-0.110

The area of ​​​​drilling the cut is determined by the formula (m 2):

(4.20)

The number of explosives in the cut is determined by the formula (kg)

(4.21)

Since rock crushing in straight cuts is carried out in conditions of one free surface, it is advisable to use one or more compensation wells, the minimum diameter of which is determined by the formula (m), to facilitate the work of cut charges:

(4.22)

Where: Wmin- distance from the well to the nearest cutting hole working for this well, m;

d w- diameter of the cutting hole, m.

Knowing the area of ​​the cut and taking the shape of the cross section in the form of one or another flat geometric figure, it is possible to determine the dimensions of the cut section and the placement parameters of the cut holes (Fig. 4.3):

Square:

slotted:

(4.27)

(4.28)

Figure 4.3 Examples of hole placement in straight cuts.

After calculating the parameters of the cut, they proceed to the calculation of the parameters of the breaking.

The total number of blast holes (including soil ones) is determined by the formulas (pieces):

For subsequent contouring:

(4.30)

For pre-contouring:

(4.31)

where: R reb- linear density of loading jackholes, kg/m;

e reb, e k- conversion factors, respectively, for breaking and contour charges.

The distance between soil holes is calculated by the formula (m):

(4.32)

The line of least resistance of soil holes is determined by the formula (m):

(4.33)

The number of soil holes and the area of ​​the part of the face, which falls on these holes, is determined by the formulas:

The number of holes intended directly for the destruction of the rock core is determined by the formula (pieces):

(4.35)

The approximate size of the grid for drilling jackholes is determined by the formula (m):

(4.36)

During the preliminary contouring of the working S to = 0.

The amount of explosives for rock breaking within the core and soil zones is determined by the formula (kg):

Based on the calculations and the layout of the holes, a summary table of blasting parameters by shape is compiled.

Table of drilling and blasting parameters

Rice. 4.4 Drill hole layout.

a - the layout of the holes; b - charge design; 1 - explosive cartridge;
2 - electric detonator.

After calculating all the parameters of the drilling and blasting complex, he draws up a passport for drilling and blasting.

The drilling and blasting passport must contain a diagram of the location of holes (in three projections), indicate the number and diameter of holes, their depth and angles of inclination, the number of blasting series, the sequence of blasting, the amount of charges in the holes, the total and specific consumption of explosives, the consumption of detonators, the length of the internal stemming of each hole and the total amount of stemming material for all holes, as well as the time of ventilation of the face.

To clarify the text part of this section, the note should include the relevant diagrams (the layout of holes, the design of the charge in the hole, the diagram of the cut, the connection diagram of detonators in the explosive network).

Calculation of the electrical explosive network.

With electric explosion of charges, it is possible to use all known schemes for connecting resistances in a circuit. The choice of the EM connection scheme depends on the number of EMs to be exploded and the homogeneity of their characteristics. When using electric explosive devices, the resistance of the explosive network is determined and the result obtained is compared with the limit value of the circuit resistance indicated in the device passport. When using power and lighting lines, the resistance of the explosive circuit is determined, then the amount of current passing through a separate ED is calculated and this value is compared with the guaranteed current value for a trouble-free explosion. For the guaranteed current, it is accepted - for 100 ED equal to 1.0 A, and when blasting ED in large groups (up to 300 pieces) 1.3 A and not less than 2.5 A when blasting with alternating current.

When connected in series, the ends of the wires of neighboring EMs are connected in series, and the extreme wires of the first and last EMs are connected to the main wires going to the current source.

The total resistance of the explosive circuit with a series connection of the ED is determined by the formula:

, Ohm (4.38)

where: R1- resistance of the main wire in the area from the explosive device to the conclusions of the explosive circuit in the working face, Ohm;

R2- resistance of additional mounting leads connecting the end wires of the ED to each other and to the main wire, Ohm;

n 1- number of EMs connected in series, pcs;

R3- resistance of one ED with end wires, Ohm.

Wire resistance is determined by the formula:

where: ρ - resistivity of the conductor material, (Ohm * mm 2) / m;

l– conductor length, m;

S- conductor cross section, mm 2.

When conducting blasting as connecting wires and for laying temporary blast lines, wires for industrial blasting of the VP brand with copper conductors in polyethylene insulation are used. The wire is produced as a single-core VP1 and two-core VP2x0.7.

Cables of the NGSHM brand are designed for laying permanent explosive lines. Conductors are made of copper wire. Conductor insulation is made of self-extinguishing polyethylene.

In exceptional cases, in agreement with the bodies of Gosgortekhnadzor, wire VP2x0.7 can be used as permanent explosive lines

Table. 4.12

Table. 4.13

Table 4.14

Hole drilling

Holes are drilled with hand drills, perforators, drilling rigs.

Hand drills- are used for drilling holes up to 3 m deep in rock with f  6. Drilling is performed directly from hands or from light supporting devices (SER-19M, ER14D-2M, ER18D-2M, ERP18D-2M). Electric core drills are used when drilling through rock with f  10 (SEK-1, EBK, EBG, EBGP-1).

where: n- number of drilling machines;

k n - machine reliability factor (0.9);

k 0- coefficient of simultaneous operation of machines (0.8 - 0.9).

The number of drilling machines is determined on the basis of 4 - 5 m 2 of the bottomhole area per one drilling machine.

Perforators- are used for drilling holes in rocks with f  5 (PP36V, PP54V, PP54VB, PP63V, PK-3, PK-9, PK-50).

Drilling productivity is determined by the formula (m/h):

(4.45)

where: k d- coefficient depending on the diameter of the hole (0.7 - 0.72 at dsh = 45 mm; 1 at dsh = 32 - 36 mm);

k p- coefficient taking into account the type of perforator (1.1 for PP63V, PP54; 1 for PP36V);

a– coefficient taking into account the change in drilling speed in various rocks (0.02 at f = 5-10; 0.3 at f = 10-16).

Drilling rigs. Holes are drilled with drilling rigs or attachments mounted on loaders.

The choice of a drilling rig for drilling holes in a horizontal mine is made taking into account the following factors:

The type of drilling machine must correspond to the strength of the rocks in the hole being drilled;

The dimensions of the drilling zone must be greater than or equal to the height and width of the face to be drilled;

The maximum length of drilled holes according to the technical characteristics of the drilling machine (installation) must be consistent with the maximum length of holes (according to the drilling and drilling certificate);

The width of the drilling rig should not exceed the vehicles used.

Drilling productivity is determined by the formula (m/h):

(4.46)

where: n- number of drilling machines at the installation, pcs;

k 0- coefficient of simultaneity in the operation of machines (0.9 - 1);

k n- installation reliability coefficient (0.8 - 0.9);

t- duration of auxiliary work (1 - 1.4 min/m);

v m- mechanical drilling speed (m/min).

Table 4.5

Drilling speed

Hole drilling time (h):

where: t p– preparatory and final work (0.5–0.7 h).

Ventilation design.

The design of ventilation of underground workings is carried out in the following sequence:

1. The ventilation method is selected;

2. A pipeline is selected and its aerodynamic characteristics are determined;

3. Calculation of the amount of air required for ventilation of workings;

4. A local ventilation fan is selected.

The installation location of the local ventilation fan (VMP) and the direction of the ventilation duct are shown in the “Ventilation Passport”. The passport also indicates the number of VMPs, their type, the diameter of the ventilation duct, the direction of fresh and outgoing ventilation jets, and security zones.

ventilation methods.

Ventilation of workings is carried out by injection, suction or combined methods.

With the injection method, fresh air is supplied through pipes to the bottom, and polluted air is removed along the working. The main advantage of this method is the effective ventilation of the bottomhole space with a significant lag of the ventilation pipes from the chest of the face. It is also possible to use flexible pipes. However, due to the fact that gases are removed over the entire cross section and along the length of the working, it is gassed, which leads to the need to install fans of greater capacity and pressure and lay air ducts with pipes of a larger diameter. This method is the most widespread.

With the suction method, toxic gases do not spread through the working, but are sucked out through the pipeline, and fresh air enters the bottomhole space along the working. The main advantage of this method is that with a sufficiently small distance of the end of the pipeline from the chest of the face, not exceeding the suction zone, the face of the working is ventilated much faster than with other methods, and there is no gas contamination of the main part of the working. This method can be used to ventilate workings when the main sources of production hazards are concentrated in the bottomhole zone. The sticking method cannot be used when driving workings through gas-bearing rocks, when working in them with rolling stock with internal combustion engines or with other sources of harmful emissions dispersed along the length of the working.

The combined method involves the use of two fans, one of which works for exhaust, and the other, installed near the bottom, for injection. This method of ventilation combines the advantages of pressure and suction methods. In terms of ventilation time, this method is the most effective. The disadvantages of this method is the blockage of the development of ventilation equipment.

Rice. 5.1 Ventilation schemes for blind workings.

a - injection; b - suction.

1 - fan; 2 - pipeline.

Table 5.1

Coefficient value R100

pipe diameter,	metal	Type M	Text-vinite
m
0.3	990.0	1284.0	481.0
0.4	228.0	305.0	108.0
0.5	72.8	100.0	33.0
0.6	25.0	40.1	12.5
0.7	11.6	28.2	5.0
0.8	5.8	9.3	2.5
0.9	3.0	5.1	1.3
1.0	1.6	3.0	0.8

Aerodynamic resistance of the pipeline. The pressure created by the fan during its operation on the ventilation pipeline is spent on overcoming the frictional resistance and local resistances, as well as on the dynamic pressure at the exit of air from the pipeline or at the entrance to it, during suction ventilation.

The aerodynamic friction resistance of the pipeline is determined by the formula:

, N * s 2 / m 8 (5.2)

Local resistance of ventilation pipelines is usually created by elbows, tees, branches and other fittings of pipes. The local resistance values ​​are given below.

Table 5.2

Resistance (N*s 2 / m 8