How to strengthen technological control measures in construction. Manual “Guidelines for the design and installation of load-bearing and enclosing structures made of screwed reinforced concrete piles. Standard of the enterprise OJSC MP \\ Gidrospetsfundamentstroy \\
Control over the production of construction and installation works.
1. Technical supervision of the customer is carried out throughout the entire construction period of the facility in order to monitor compliance with design solutions, construction timeframes and regulatory requirements, including the quality of construction and installation work, compliance of construction costs with approved projects and estimates. When performing their duties, technical supervision inspectors should not interfere with the operational and economic activities of the contractor.
2. The representative of the customer's technical supervision, exercising technical supervision over the construction, is subordinate only to the head, on whose behalf he performs this work (the head of the capital construction department, the head of the technical supervision inspection).
3. Instructions and requirements of the customer's technical supervision representative on the quality of the materials, products and structures used, equipment and apparatus to be installed, as well as the quality of construction and installation work are mandatory for the contractor.
4. For employees of technical supervision, instructions of the State Architectural and Construction Supervision bodies on the quality of construction, performance of work in accordance with the project, compliance with the requirements of SNiP, rules and technical conditions for the production and acceptance of construction and installation work are mandatory.
6. The representative of the customer's technical supervision has the right:
- during working hours, check the progress and quality of work performed, as well as the quality building materials, semi-finished products, parts and structures, completeness and quality of logging of work and phased acceptance of hidden elements;
- to suspend the production of construction and installation works, if they are carried out in violation of the requirements of the project and SNiP, as well as in the case of the use of low-quality materials and products, making an appropriate entry about this in the general work log;
- do not accept for payment work and structures, performed poorly, with deviations from the project, SNiP, TU and other regulatory documents, until they are altered or defects are eliminated;
- to raise a question before the management of the contractor construction organization, and, if necessary, before your management about bringing to justice the persons guilty of violating the legislation on capital construction, SNiP, production rules, quality control and acceptance of works and other regulatory and technical documents;
- to make proposals to their management, as well as to the management of construction and design organizations on the introduction of progressive methods of work production, new structures and materials that improve quality, reduce costs and reduce construction time;
- to take part (at the invitation of the contractor) in the work of the internal control commissions of the contractor organization and in the work of the complex commissions, in the quality control of construction and installation work carried out by persons inspecting the construction, in the work of the working and state acceptance commissions.
7. The customer's technical supervision representative is personally responsible for:
- acceptance from the contractor according to the certificate of inspection of hidden works, according to the certificate of intermediate acceptance of critical structures, according to the log of the stage-by-stage acceptance of hidden works and intermediate acceptance of structural elements or according to acts of acceptance of poor-quality work with deviations from the requirements of the project, SNiP, TU and other regulatory documents;
- registration of certificates of inspection of hidden works and intermediate acceptance of critical structures, as well as records in the stage-by-stage acceptance of hidden works and intermediate acceptance of structural elements, the parameters and characteristics of which (in kind) do not correspond to those in the specified documents;
- presentation of overstated volumes and cost of work performed to the contractor;
- failure to take measures to eliminate comments and deficiencies identified during the construction process.
8. The work of technical supervision at the facility ends only after the complete solution of all issues related to putting it into operation and closing financing.
| Cracking of a newly laid roll waterproofing coating of a flat roof. | ||
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| Adjoining waterproofing coating flat roof to vertical structures not done well. | ||
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| Damage to the asphalt pavement as a result of poor-quality rolling. | ||
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| Reinforced concrete surface cracking structures due to improper care behind the concrete. | ||
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| Crack formation along the production seam. |
This manual has been developed to assist organizations that design, install and operate horizontal drainage piping systems. The manual contains recommendations, convenient for design organizations, on the selection of corrugated polyethylene pipes full factory readiness of the production of NPO Stroypolymer, namely: depending on the second flow rate of the inflow and the slope of the pipeline, its diameter and the number of slotted cuts are selected. For cases where the drainage slope is unknown and has to be determined, the manual contains a convenient nomogram for calculating the diameter of the pipeline, as well as formulas and tables for determining its slope. All recommendations for hydraulic calculations are based on calculation formulas and regulations of the set of rules SP 40-102-2000 "Design and installation of pipelines for water supply and sewerage systems made of polymer materials. General requirements".
The manual contains a range of pipes for the construction of drainages produced by NPO Stroypolymer.
GOSSTROY RUSSIA
STATE RESEARCH CENTER "CONSTRUCTION»
SCIENTIFIC RESEARCH, DESIGN AND RESEARCH AND DESIGN AND TECHNOLOGICAL INSTITUTE OF FOUNDATIONS OF SUBGROUND STRUCTURES (SUE NIIOSP them. N.M. Garsevanova)
GUIDE
on design and construction
bearing and enclosing structures
of screw-screw
reinforced concrete piles
Enterprise standard
OJSC MP "Gidrospetsfundamentstroy"
Moscow 2004
Agreed:
Chief Engineer
State unitary enterprise design and survey
institute "Fundamentproekt" candidate of technical sciences
This "Guide" has been developed and adopted as a standard of the enterprise Open Joint Stock Company Moscow Enterprise Gidrospetsfundamentstroy.
This standard may only be used by the specified organization. In the event of unauthorized use of this standard by a third organization, the perpetrators are subject to criminal liability in accordance with the law of the Russian Federation "On Copyright" No. 5351-1 of July 9, 1993 Design institutes can apply this standard in the design of objects erected by OJSC MP Gidrospetsfundamentstroy, and others organizations - written permission of OJSC MP Gidrospetsfundamentstroy and consent of the patent holder.
The manual was developed at the Research Institute of Foundations and Underground Structures. N.M. Gersevanov State Construction Committee of the Russian Federation. Participants in the development of the guide:
from NIIOSP them. N.M. Gersevanova - Ph.D. Mariupolskiy L.G., Ph.D. Dzhantimirov Kh.A., Astrakhanov B.N .;
from JSC MP "Gidrospetsfundamentstroy" - Ikusov A.G., Basiev A.N .;
from OOO PO "Foundations and fences" - VF Shcherbatov, V.A .; Mikheenkov;
from LLC "UNR - 321 A" - Lazareva TS, Sulimanov KM;
from LLC "Fundamentstroy 2001" - Lokhtaev GA, Ivashkov NV
In accordance with the concept of development of Moscow, construction sites for housing and civil purposes are located within the city, often in areas with difficult engineering and geological conditions, areas of relatively new development due to its compaction and completion, in the central part of the city - next to existing buildings and in areas where reconstructed buildings, etc.
Taking into account the complexity of the geotechnical conditions and the increased environmental requirements for the production of pile works on construction sites in Moscow, the current Moscow building codes set stricter than previously established restrictions on the use of the most common methods of pile driving, in particular, driving. So, according to clause 9.9 of the Recommendations, driving by driving piles and sheet piles closer than 10 m from buildings of architectural and historical value, as well as from structures with shock-sensitive equipment, is not allowed. The admissibility of using driven piles near existing buildings is established only based on the results of instrumental measurements of vibrations during test pile driving, determining the level of vibration impact of driving on structures and its compliance with regulatory restrictions.
Considering these requirements, the Moscow enterprise "Gidrospetsfundamentstroy" at one time proposed a technology for the construction of foundation structures using metal screw-on piles (RF patent No. 2073084), which practically does not have a negative impact on the state of objects located in close proximity to the structure being built.
Currently, this design is widely used at construction sites in Moscow. Instructions for the calculation, design and construction of foundations on metal screw-on piles are included in the current Moscow building codes ,,,.
At the same time, the practice of constructing foundations for screwed piles has shown the possibility of more effective use of the proposed technology due to the use of reinforced concrete piles as a submerged pile element. round section with screw winding.
The description of this proposal is presented by the patent of the Russian Federation No. 2208089 dated July 10, 2003.
This Guide provides the basic regulations for the calculation, design, manufacture and driving of screwed reinforced concrete piles with a cross section of up to 410 mm. With the accumulation of experimental data, some positions of the Guide can be subsequently supplemented and refined.
1. SNiP10-01-94. System of regulatory documents in construction. Basic provisions.
2. SNiP 2.01.07-85. Loads and impacts.
3. SNiP 2.02.01-83 *. Foundations of buildings and structures.
4. SNiP2.02.03-85. Pile foundations.
5. SNiP 2.03.01-84 *. Concrete and reinforced concrete structures.
6. SNiP 3.02.01-87. Earthen structures, foundations and foundations.
7. SNiP11-02-96. Engineering surveys for construction. Basic provisions.
8.SP11-105-97. Engineering and geological surveys for construction (parts 1, 2 and 3).
9.GOST 5686-94. Soils - Field test methods with piles.
10. GOST 12248-96. Soils. Methods for laboratory determination of strength and deformability characteristics.
11. GOST 19804.5-83. Hollow piles with circular cross-section and reinforced concrete shell piles with non-tensioning reinforcement. Design and dimensions.
12. GOST19912-01. Soils. Field test methods by static and dynamic probing.
13. Instruction for design and construction pile foundations buildings and structures in Moscow. Moskomarkhitektura, 2001.
14. BCH490-87. Design and construction of pile foundations and sheet piling in conditions of reconstruction industrial enterprises and urban development. Minmontazhspetsstroy, 1987.
15. MGSN 2.07-01. Foundations, foundations and underground structures.
18. Guidelines for the design and construction of fencing and load-bearing structures from screw-screwed piles.NIIOSP them. Gersevanov, M. 1996.
21. Patents: No. 2073084 dated July 31, 1995; No. 2200795 of 28.08.2001; No. 2208089 dated July 10, 2003
1. General Provisions
1.1. This Guide applies to the design and construction of enclosing structures and supporting structures (foundations) off-rock soils made of screwed reinforced concrete piles (BZZhS) with a diameter of 315 - 410 mm and a length of up to 14 m, manufactured in accordance with the RF patent No. 2208089 dated 10.07.2003. These piles are immersed into the ground by screwing them into the head using drilling rigs such as CO-2 or other similar mechanisms.
The Guidelines do not apply to the design and construction of screwed reinforced concrete piles in seismic regions, in areas with permafrost and subsidence soils.
1.2. The design of facilities using screwed reinforced concrete piles should be carried out only by specialized design organizations that have a license and certificate for this type of activity. In the case of a one-time application, it is allowed to design the foundations of the BZZhS by non-specialized organizations together with the authors of this Manual.
It is prohibited to carry out work on the installation of screwed reinforced concrete piles by organizations that do not have a license for this type of work.
1.3. In the working drawings of foundations made of screwed reinforced concrete piles, the main parameters of the BZZhS should be indicated - the section of the idle length, as well as the bearing capacity and the corresponding permissible load on the pile, which, as a rule, are specified by static testing of the piles in the ground before the start or during construction.
If necessary, the design organization must promptly adjust the design of the pile foundations based on the test results, without delaying the execution of construction work.
1.4. The design and survey work when using screwed-in reinforced concrete piles as load-bearing structures for buildings and structures of I and II class of responsibility must include experimental work on trial immersion and testing BZZhS static loads. For these purposes, an appropriate experimental site should be organized on the construction site.
1.5. Before starting work on the reconstruction of the building and for new construction near existing facilities, it is necessary to carry out the acceptance and certification of the latter. The act of the commission should reflect the state of the object, the expediency of carrying out reinforcing work and the possibility of finding people in the reinforced building during the period of work.
2. Scope of application of screwed-in reinforced concrete piles
2.1. Screw-borne reinforced concrete piles are used in the following cases:
when building new facilities next to existing ones;
For fencing deep excavations in dense urban areas;
To strengthen the foundations and lead pile supports in the immediate vicinity of the reconstructed buildings and structures;
For solving problems of anti-landslide protection;
For the device of cut-off screens in the ground, allowing to exclude the influence of the objects under construction on nearby buildings and facilities, etc.
In cases where, according to the current requirements, during the production of work on the construction of foundations, ground movements, quicksand leaks, significant vibrations, shocks and noises are not allowed.
2.2 Drilled screw reinforced concrete piles are advisable to use:
Instead of driven and vibro-submerged elements of enclosing structures, as well as driven and vibro-submerged piles, mainly in cases of impermissible dynamic impacts on nearby buildings and structures and their foundations during the immersion of these elements and piles;
Instead of bored piles, when it is inadmissible to drill wells of the required depth for these piles near existing buildings and structures (in particular, by auger method or with advanced development and excavation of soil from wells below the casing pipe), especially in water-saturated soils.
2.3. Screw-boring reinforced concrete piles are used with design loads of up to 50-70 tf per pile, depending on its parameters (diameter and depth) and soil conditions.
3. Construction of screwed-in reinforced concrete piles
3.1. A bore-screwed reinforced concrete pile () is a concrete cylinder with a diameter of 315-410 mm, reinforced with a spatial metal frame () of 6 vertical longitudinal reinforcement bars with a diameter of 12-28 mm of class A-III, interconnected by rings of pipes with a diameter of 273 mm and a width of 50 mm, step 1000 mm and external horizontal spiral winding from reinforcement with a diameter of 8-10 mm class A-III.
To ensure the required protective layer and external winding device, at the locations of the support rings, restraints are welded to the frame in the form of cuttings of reinforcement with a diameter of 12 mm and embedded elements made of plate with a thickness t\u003d 4 mm 40 mm wide for the entire length of the pile.
In the upper part of the pile there is a metal head () made of a pipe with a diameter of 273-377 mm and a length of 400 mm with holes with a diameter of 65 mm for securing the pile on drilling equipment during submersion.
On the outer surface of the reinforced concrete pile along the entire length, a spiral winding is fixed opposite to the direction of the spiral reinforcement of the frame, intended for removal to the surface of the drilled soil when the pile is immersed ().
Spiral winding is a continuous round metal rod, usually made of rebar with a diameter of 12-28 mm class A-Iwelded to the embedded strip in increments of 0.5 d up to 2.0 dwhere d- outside diameter pipes.
At the lower end (heel) of the pile, a metal tip (knife) is mounted, which is necessary for drilling the bottom of the well when the pile is immersed ().
3.2. As a rule, the direction of the outer winding is right. This means that the winding is done clockwise in the direction from the butt end of the pile point. Accordingly, the opposite direction is left.
In some cases, for example, for the construction of piles that are in contact with each other, it is allowed to use piles by left external winding ().
Piles with left external winding should be made separately from others. They are reinforced with frames with spiral reinforcement wound in the right direction, and after manufacturing they receive a marking containing the index "L".
3.3. The length of one-piece screwed reinforced concrete piles is up to 10m. If it is necessary to use piles of greater length (up to 14 m), they are made joined. In this case, additional sections with a length of 2-4 m are used, equipped at the ends with tubular embedded elements. The joint of the lower and additional section is carried out by welding.
3.4. Reinforced concrete screw-down piles are marked in accordance with the requirements of GOST 19804-89.
Example of pile marking:
Round solid section screwed-in reinforced concrete pile with stress-free reinforcement:
The symbol for the type of pile reinforcement is given in Table 1:
| Reinforcement symbol | Diameter and class of longitudinal reinforcement |
| 10 A-III |
|
| 12 A-III |
|
| 14 A-III |
|
| 16 A-III |
|
| 18 A-III |
|
| 20 A-III |
|
| 22 A-III |
|
| 25 A-III |
4. Manufacturing of screwed reinforced concrete piles
4.1. The raw materials for the production of screwed reinforced concrete piles must have certificates and comply with the current state standards:
Cement - GOST 10178 -76
Crushed stone, gravel, sand - GOST 10268-80
Armature - GOST10922 -75; GOST5781-82.
4.2. Reinforced concrete screw-down piles with a diameter of 315-410 mm are made at a work bench for the installation of monolithic reinforced concrete structures, using specialized equipment for the production of reinforced concrete products,
4.3. The procedure for manufacturing reinforced concrete screw-screw piles:
a) Inventory metal formwork is manufactured, which is a pipe cut along the length with a diameter of 325 × 8 mm or a diameter of 426 × 8 mm and a length of up to 10 m, locks (on one side) and hinges (on the opposite side) are mounted along the seams of the cuts for fastening and fastening the formwork when concreting ().
If it is necessary to make a pile of less length than 10 meters, a transverse metal insert is attached to the frame inside the formwork so that a pile of the required length is obtained during concreting.
Piles more than 10 meters long are made docked, for which additional 2 meters long sections are used.
b) The metal frame described above is made, the tip () is welded to the frame.
c) The metal frame is laid in the formwork, which is open at one end for concrete supply, and at the other end is plugged with the end of the frame.
d) Inventory formwork, with the assembled frame, is suspended in a vertical position, so that the tip of the frame is at the lowest point.
e) The supply of cast concrete of grade up to B25 is made (draft cone up to 20 cm).
f) After the concrete is fed, the mixture is vibrated along the entire length of the pile in accordance with the requirements of SNiP.
g) After the concrete has set 80% of the strength, the concrete pile is stripped.
h) The finished pile is placed on a welding stand and wound from reinforcement with a diameter of 12-28 mm of class A-I along the lateral surface of the pile.
i) The manufactured piles, before being sent to the immersion site, are stored in stacks of no more than 4 rows in height.
4.4. During the production of piles, continuous control over the quality of the work performed (quality of welds, composition of concrete mixture, observance of geometric dimensions) should be carried out, with the preparation of a quality control log.
4.5. The deviation of the actual dimensions of the manufactured BZZhS from the design should not exceed the following values:
In length - no more than ± 100 mm;
By diameter d - ± 0.05 d;
On the curvature of the longitudinal axis - no more than 0.001 of the pile length;
Spiral winding step - no more than 0.1 design step.
4.6. For each batch of piles manufactured by the manufacturer, a technical passport is submitted containing data on the date of manufacture, pile dimensions, concrete grade, reinforcement, winding direction and other information in accordance with GOST 19804-83.
5. Technology of driving screw-in reinforced concrete piles
5.1. The immersion of the BZZhS is carried out by a KG-12M pile driver with attachments CO-2, or a CO-1200 type installation, as well as similar installations with a power of at least 45 kW.
5.2. Work on the immersion of screwed piles is carried out in the following sequence:
Moving and installing a pile driver to the pile immersion site;
Pulling the piles from the storage site;
Fastening the upper end of the pile with the capture of the working body of the machine (filling the pile into the attachments CO-2) (the structure of the interface of the pile with the attachments ();
Installation of the machine in working position (centering in plan, elimination of possible roll);
Screwing the pile up to the design mark by transferring the torque from the attachments (CO-2) to the pile through the adapter.
Detachment of the working body of the machine from the pile and transferring it, if necessary, to the transport position.
5.3. If it is advisable to increase the density of the soils "ground" during the immersion of the pile in the zone of the spiral winding and the location of the tip, the soil is poured into the gap between the base and the pile formed on the surface during its reverse rotation before the pile starts to rise (). In low-moisture clayey soils, such a bedding should be accompanied by adding water to wet the pile shaft and soil at the contact with the snow.
5.4. If it is expedient to support the lower end of the pile on the soil undisturbed during its immersion, the submerged pile is poured with a diesel hammer, vibratory pile driver or other percussion mechanism with the immersion of the piles to a double knife height.
5.5. If, according to the data of engineering and geological surveys, dense soils or soils containing coarse-grained or other inclusions that impede the immersion of the pile directly into the soil mass lie at the design depth of the pile or on its part, it is allowed to use leader wells with a diameter of at least 0.1d less than the borehole diameter piles (d), with the location of their bottom at least 1 m above the design mark of the location of the lower ends of the piles.
5.6. In unstable soils, instead of leading wells, the soil should be loosened with an auger drill (without lifting it during drilling) within the soil massif (cylinder), the diameter of which is not less than 0.1d less than the diameter of the pile shaft, and the marks of the bottom massif are not less than 0.5 m above the design elevation of the location of the lower ends of the piles.
6. Requirements for source documentation
The initial data for the design of enclosing and supporting structures from BZZhS should contain the following design and survey materials:
General plan of the site with the marked contours of the projected structure (with axes), engineering and geological workings, planning marks, information about the nearest constructed and proposed construction of underground structures.
Technical report on the results of engineering and geological surveys at the site of the projected facility.
The general constructive solution of the above-ground part of the structure with the necessary drawings (plans, sections), the absolute mark of the 1st floor or the top of the foundation.
Drawings of the underground part of the facility with an indication of the supporting structures, their dimensions and bottom elevations, the dimensions and depth of the underground premises, channels and equipment foundations, the location of the openings in the walls.
Data on the design loads on fences and foundations in the required combinations, indicating the temporary loads and the cyclicity of their action, as well as the design loads on the floors and places of their application. Information about possible changes during operation of loads on foundations and the nature of their impact.
Data on the limiting values \u200b\u200bof the total and uneven settlement of the designed structure.
7. Requirements for engineering and geological surveys
7.1. Geotechnical surveys for the design of enclosing and supporting structures made of screw-screwed piles should be carried out in compositions and volumes regulated by SP11-105-97, and ensure that the physical and mechanical characteristics of soils necessary for calculations are obtained for each geotechnical element within the depths of soil investigation specified in cl. 7.2 and 7.3.
7.2. The depth of the study of soils in the design of enclosing structures made of screw-screw piles should be at least 1 m below the projected immersion depth of the lower ends of the piles.
7.3. The depth of the study of soils in the design of supporting structures made of screw-screw piles must comply with the requirements of clause 8.7 of SP11-105-97.
7.4. When buried within the thickness of clay soils studied during exploration, they must be investigated at least by laboratory methods, and the composition of laboratory determinations of soil properties must comply with the requirements of Appendix M to SP11-105-97.
7.5. When lying within the studied thickness of sandy soils, in addition to determining their properties by laboratory methods in accordance with the requirements of Appendix M to SP11-105-97, it is necessary to perform static and dynamic sounding of the soils, guided by GOST 1991-2001.
7.6. A technical report based on the results of engineering and geological surveys for the design of enclosing and supporting structures made of screwed reinforced concrete piles should contain:
Schematic plan of the building with indication of transverse and longitudinal boundary axes, location of wells, sounding points, places of testing of soils, experimental works, profile lines;
Geological and lithological description of the construction site and engineering and geological sections, tied to the axes of buildings;
Information about the standard and design characteristics of the primer for each engineering-geological element of the active call;
Information about the maximum depth of freezing of the site soils;
Characteristics of the hydrogeological conditions of the site, including data on the quantity and position of groundwater horizons, sources of their food, connection with nearby water bodies, direction of flows, discharge points, degree of aggressiveness - natural or as a result of infiltration into the soil of industrial or wastewater, forecast of changes in groundwater levels during the operation of buildings;
Materials of laboratory, field studies of soils and experimental work;
All soil characteristics should be presented in the report, taking into account the forecast of possible changes (during the construction and operation of the building) in the engineering-geological and hydrogeological conditions of the site.
In the case of revealing in the course of exploration interlayers of loose sands, weak clayey soils and hazardous geological processes (karst-suffusion and landslide), it is necessary to provide data on changes in their power within the core under the projected building or structure.
8. Design of enclosing and supporting structures made of screwed reinforced concrete piles
8.1. The section, reinforcement and length of screwed piles when used as enclosing structures, as well as their number, are determined by calculations as for a retaining wall according to -, - section of this Guide.
8.2. The diameter, length and reinforcement of BZZhS when used as load-bearing structures are determined by calculations as for a pile foundation in accordance with Section 9 of the Guide.
8.3. Distance from the axes of screwed piles to the outer edges building structures nearby buildings and structures must be assigned at least 0.5d + 20 cm, where d is the diameter of the pile.
8.4. Reinforcement of BZZhS frames should be selected based on the calculation for the perception of the maximum torque developed by the mechanism used for driving the piles ().
8.5. The diameter of the outer spiral winding () is recommended to be taken in the range from 0.04 to 0.06 of the pile shaft diameter, with smaller values \u200b\u200bcorresponding to larger diameters.
8.7. When designing screw-screw piles used as load-bearing structures, as well as enclosing structures operated for a long time, it is necessary to take into account the corrosive properties of soils and underground waters, which must be determined by special studies provided for by SNiP 1.02.07-87. Depending on the corrosivity of the medium, appropriate anticorrosive protective measures are prescribed.
8.8. The design of structures from the BZZhS must contain instructions on the need for finishing the submerged piles, or on the use of other methods of increasing the resistance of soils in the near-pile space, as provided for -.
8.9. Designed in accordance with the dimensions, design and number of screwed piles are specified according to the results of experimental work carried out in accordance with this Guide.
9 . Calculate the design of enclosing and supporting structures from screw-screwed reinforced concrete piles.
9.1. Calculations of screw-screwed piles when using them as enclosing structures should be performed as for a supporting structure using the Wall-3 software package developed by NIIOSP them. N.M. Gersevanov.
9.2. Preliminary selection of the deepening of screwed piles below the bottom of the pit (h) sandy soils and the distance between the axes of adjacent piles (m) is recommended to be carried out using formulas (1), (2), (3), (4):
(1)
(2)
where: H- pit depth;
d is the diameter of the pile shaft.
(3)
where: g - specific weight of soil;
j- angle of internal friction of the soil.
9.3. Calculations of screw-screwed piles when used as load-bearing structures (pile foundations) must be performed in accordance with the requirements of Section 3 of SNiP 2.02.03-85.
9.4. Calculations for the bearing capacity of the foundation soil of the piles include the determination of the bearing capacity of the screwed-in pile based on the physical and mechanical characteristics of soils and the results of experimental work, if the latter have been completed.
9.5. The calculation of the bearing capacity of a bored pile according to its physical and mechanical characteristics is performed using the formula (5):
where: γc- the coefficient of the working conditions of the pile in the soil, taken γc=1;
R - the calculated soil resistance under the lower end of the pile, kPa (tf / m2), taken according to instructions;
A - cross-sectional area of \u200b\u200bthe pile shaft, gross, m 2;
u- the perimeter of the cross-section of the pile shaft, m;
ƒi is the design resistance of the i-th layer of the foundation soil on the lateral surface of the pile, kPa (tf / m²), taken according to SNiP 2.02.03-85;
h i - thickness of the i-th layer of soil in contact with the lateral surface of the pile, m;
γ cR is the coefficient of the working conditions of the soil under the lower end of the pile, taken equal to 0.9 for sands regardless of their density and clayey soils with soft-andugoplastic consistency, and equal to 0.8 for clay soils of semi-solid and solid consistency;
γ cƒ is the coefficient of the working conditions of the soil on the lateral surface of the pile, taken equal to 1 when the pile is immersed from the soil surface into the undisturbed soil massif, equal to 0.8 when the pile is immersed in the soil mass loosened by preliminary drilling and equal to 0.6 when the pile is immersed in the leader well.
9.6. The design soil resistance of the lower end of the pile should be determined by the formula (6):
(6)
where: α 1, α2 - dimensionless coefficients taken by depending on the calculated angle of internal soil friction j1, the grounds determined in accordance with the instructions of SNiP 2.02.03-85;
c 1 - the calculated value of the specific cohesion of the base soil, kPa (tf / m 2);
γ 1 - average calculated value specific gravity soils kN / m (tf / m 3), lying above the lower end of the pile (with water-saturated soils, taking into account the weighing effect of water);
h - pile immersion depth, m.
| Calculated valuebase, φ 1 deg | Odds | Calculated valueangle of internal friction of the soilbase, φ 1 deg | Odds |
||
| a 1 | a 2 | a 1 | a 2 |
||
4. Manufacturing of screwed reinforced concrete piles
9.7. The calculation of the bearing capacity of a screwed-in pile based on the results of experimental work, including testing of piles with static and dynamic loads, is carried out in accordance with the instructions in Section 5 of SNiP 2.02.03-85.
9.8. The calculation of the base of foundations from screw-screwed piles to sub-deformations is carried out in accordance with the requirements of Section 6 of SNiP 2.02.03-85.
9.9. The calculation of the strength of the BZZhS barrel should be made in accordance with the design standards reinforced concrete structures SNiP 2.03.01-84 * and pile foundations SNiP2.02.03-85, including for the following loads and effects:
Transport and assembly (lifting on a pile driver) loads;
Torsion when immersed in the ground;
For vertical, horizontal loads, bending moments, or for their joint action.
9.10. To prevent the destruction of the pile when immersed in the ground, it is necessary that the torsional resistance of the pile section be more than 1.3 from the moment of torsion of the unit. Otherwise, it is necessary to provide for the installation of the limiting torque coupling, or to reduce the maximum torsion moment of the installation, or to recalculate the pile reinforcement.
ten . Experimental work and testing of screwed screws with swaystatic and dynamic load
10.1. To clarify the number and sizes of drilled-screwed reinforced concrete piles, check the selected immersion technology, confirm their bearing capacity, before starting the main work on the installation of the designed structures, experimental work should be performed on a specially designated experimental site.
10.2. Experimental work includes trial driving of piles and investigation of the interaction with surrounding soils of fragments of enclosing and supporting structures made of screw-screwed piles or individual piles and should be carried out according to special programs, including testing of piles with static and dynamic loads and taking into account the requirements of the interstate standard GOST5686-94 “Soils. Field test methods with piles ".
10.3. The experimental site should be located at a distance of no more than 5 m from mine workings, from which soil monoliths were selected for laboratory tests and where static sounding was performed.
A trial dive and testing should also be performed on areas where weak soils characteristic of the site are identified.
The number of bored screwed piles to be tested in the construction should be:
When testing piles with a static indentation load - up to 0.5% of the total number of piles at a given object, but not less than 4 pcs;
When testing piles with static horizontal load - at least 2 pcs;
When tested by dynamic load - not less than 6 pcs.
10.4. Test driving of piles should be carried out in at least 5 points (according to the "envelope") and combined with points where piles are tested.
10.5. In the process of driving the piles, a log is kept of their immersion in shape, and every 0.5 m, the submersion coefficient k m is determined, calculated as the ratio of the theoretical number of revolutions of the pile per 0.5 m of its immersion n Tto the actual number of revolutions n, determined by multiplying the speed of rotation of the output shaft of the installation for immersion by the duration of immersion of the pile by 0.5 m. In this case, the theoretical number of revolutions of the pile by 0.5 m of its immersion n Tis determined by dividing Δ l\u003d 0.5 m per spiral winding step.
The log records all cases when obstacles are encountered that make it difficult to sink piles. The information obtained for the piles tested at the experimental site will serve as a reference (standard) for choosing the mode and quality control of the piles driven during their mass immersion in similar soil conditions.
10.6. Based on the results of the test driving of piles, the need for the use of leader wells (), as well as loosening of the soil () is determined. If such additional measures are included in the project, then a test driving of the piles is performed with the indicated measures.
10.7. Piles subjected to a test drive are removed from the soil and inspected, with any defects noted in the log.
10.8. Piles immersed in the ground without additional operations to increase their bearing capacity mentioned in and this Manual should be subjected to static load tests not earlier than 9 days after immersion.
10.9. Piles immersed in the ground according to the technologies described in and of this Manual can be tested 5 days after immersion.
If the bearing capacity of the piles loaded according to the specified technologies, determined according to the test data by static loads, differs from the bearing capacity of the piles driven along by not more than 15%, then, in agreement with the author of the project, additional operations in accordance with this Guide can be canceled.
10.10. Field tests of screw-screwed piles with static loading should be carried out in accordance with the requirements of GOST 5686-94 "Soils. Methods for field testing with piles".
10.11. In the case of using the BZZhS immersion technology mentioned in this Manual, part of the tests of piles with static loads can be replaced by tests of piles with dynamic loads in accordance with GOST 5686-94 with the determination of its bearing capacity in accordance with the requirements of SNiP 2.02.03-85.
11. Installation of enclosing and supporting structures of reinforced concrete piles
11.1. The installation of the enclosing and supporting structures of screw-on piles is carried out in the following sequence:
Preparatory work for construction site;
Geodetic breakdown of the axes of the vertical walls of the pits and individual piles or the axes of the foundations and individual piles;
Driving piles;
Delivery and acceptance of submerged piles;
Construction of foundation pits with fastening of its walls or foundation grillages;
Delivery and acceptance of grillages.
11.2. Prior to the commencement of work on the immersion of screwed reinforced concrete piles, the following preparatory work must be performed:
a) transfer all ground and underground communications from the pit. In case of impossibility of transferring communications from the pile field or hazardous zone, the communications route is determined by drilling, marked with signs and measures are taken to protect communications from destruction when piles are screwed in;
b) plan and prepare the foundation, accept by act of commission with the participation of the customer and the contractor;
c) to mount and test the pile driver in the pit, accept the commission as part of the work foreman (foreman) and the pile driver, make an entry in the work log;
d) ensure the safe performance of work in accordance with SNiP 12-03-2001 "Labor safety in construction", SNiP 12-04-2002 "Labor safety in construction. Part 2. Construction production "and" Rules for the construction and safe operation of lifting machines ".
11.3. If it is necessary to carry out work in the winter, one of the following activities should be carried out:
Preservation of soil from freezing by pre-warming in places where piles are immersed;
Pre-thawing of the soil at the pile sinking sites;
Drilling a leader well to the freezing depth.
11.4. When breaking down the axes of screwed piles, the deviation from the design position in the plan should not exceed the values \u200b\u200bregulated by SNiP 3.01.03-84 ("Geodetic works in construction"). The design position of the svay is recommended to be fixed in place with dug metal pins driven into a depth of 0.2-0.3 m.
In cases where the marking interferes with the operational movements of the pile driver, the alignment axes of the piles are taken out of the work of the pile driver and pile laying.
At the same time, it should be possible to quickly and accurately determine the place of pile driving (for example, by tensioning two intersecting strings, using templates, etc.).
11.5. Before the immersion of screwed piles, the following are made:
Checking the documentation for their manufacture;
Inspection of piles to identify defects;
Pile marking along the length (from the lower end - the pile tip to the upper end in 0.5 m).
11.6. It is recommended to drive screwed piles using drilling rigs such as CO-2 or CO-1200, as described in this Manual.
11.7. In the process of driving screw-screwed piles, every 0.5 m should be recorded and recorded in the log () the duration of the pile driving. When piles are immersed by a value not multiple of 0.5 m, the immersion duration must be fixed at the end of the immersion as well.
11.8. In order to minimize the disturbance of the soil structure when driving the piles and reduce the immersion time, the value of the axial surcharge should be consistent with the density of the soil being passed. In the process of driving the pile, the axial surcharge is corrected in such a way that the nwas possibly closer to 1.0.
11.9. During production immersion of BZZhS, the screwing mode (immersion coefficient, immersion speed and number of revolutions) should be compared with the reference mode achieved when the tested piles were immersed in the test area. At the same time, significant differences from the reference mode, for example, with excessively fast immersion (V production limit\u003e 2V experimental limit) may indicate a pile breakage during the screwing process. In the event that V production burial\u003e 2V experimental burial, the production pile must be removed to the surface by reverse rotation and inspected to establish its integrity. In the event of a pile breakage, it is necessary to clarify its possible cause (manufacturing defect, inconsistency of the actual ground conditions with the design ones, etc.) and immerse the double at a distance of ≈1.5d from the primary pile.
If the noted discrepancies are not related to damage to the pile, then control drilling of the well should be performed, or sounding (static or dynamic) to clarify the composition and condition of the foundation soils.
11.10. The deviations of the planned position of the pile must exceed the permissible values \u200b\u200bgiven in Table 3:
| Location of screw-screw reinforced concrete piles | Permissible deviations of pile axes in plan |
| 1. Single row: |
|
| across the axis of the pile row | 0.2 diameter |
| along the axis of the pile row | 0.3 diameter |
| 2. Bushes and belts with piles in two and three rows: |
|
| for extreme piles across the axis | 0.2 diameter |
| inside the pile field | 0.3 diameter |
| 3. Continuous pile field under the entire building or structure: |
|
| for extreme piles | 0.2 diameter |
| for medium piles | 0.4 diameter |
| 4. Single piles | |
11.11. In some cases, with appropriate justification by calculation and agreement with the design organization, it is allowed to change the location of the piles in the course of the work (extraction of piles when meeting with a displaced accumulation of gravel, large boulders, etc. and re-immersion of the piles).
11.12. If the lower end of the pile, immersed to the design level, turns out to be in a layer of soft soil, as a rule, it is advisable to build up the pile and submerge it to a greater depth.
Control over the strength of the soil traversed by the lower end of the pile is carried out according to the readings of instruments reflecting the values \u200b\u200bof the torque, taking into account the duration of the pile's immersion by 0.5 m.
11.13. After the completion of work on the immersion of screwed piles, a summary sheet of the loaded piles is drawn up ().
12. Acceptance of enclosing and supporting structures for screw-in reinforced concrete piles
12.1. When accepting enclosing and supporting structures of screw-screwed piles, the following documentation is presented:
Design of enclosing and supporting structures in the ground;
Project of work production;
Geotechnical survey report;
Experimental work documentation;
Schemes for geodetic division and fixing of pile axes;
Pile driving logs;
Consolidated statements of submerged piles;
Executive layouts of the piles with an indication of their deviations in plan and height;
Concrete mix passports;
Acts of laboratory tests of control concrete cubes;
Acceptance certificates of reinforcing cages.
12.2. Acceptance must be accompanied by:
Study of the submitted documentation;
Inspection of piles with verification of the conformity of the work performed to the project and this Guide;
Instrumental verification of the correct position of the piles;
Control tests of piles, if their bearing capacity is in doubt.
12.3. During the acceptance process, the following are identified:
Compliance with the bearing capacity of the piles according to the data of static tests calculated for the project;
Pile deviations in plan from the design position;
Correspondence of the sizes of piles, shown in the magazines, and in kind;
Compliance of grades of concrete mass, concrete strength in the head of the piles, as well as reinforcement of piles with the design.
12.4. Deviation of piles from the design position in the plan should not exceed the deviations regulated by SNiP 3.02.01-87.
12.5. The inclination of the pile axis from the design position should not exceed 1 cm per 1 m of the pile length.
12.6. The admissibility of using piles with deviations above indicated in is established by the author of the project of the enclosing and supporting structures.
12.7. Acceptance of piles is formalized by an act of the commission in the composition of representatives of the customer, general contractor and work performers, in which all defects identified during the acceptance process must be noted, the time frame for their elimination is indicated and an overall assessment of the quality of work is given.
Appendix 3. Summary sheet of loaded BZZhS
Appendix 3 to the joint venture
→ 1.4 Quality control of construction and installation works
Section 2. Excavation
2.1 General
2.2 Characteristics and classification of soils
2.3 Stake out trails
2.4 Fencing of earthworks
1.4 Quality control of construction and installation works
1.4.1 A special place in the fulfillment of the contractor's contractual obligations for the construction of local telephone communication facilities is taken by the issues of quality control of construction and installation works, which is determined by the compliance of their indicators with the requirements of the project and regulatory documentation.
1.4.2 During technical preparation construction production It is recommended to carry out the following measures to improve the quality of construction and installation work: study of project documentation and decision-making to improve the organization of work, to introduce advanced technology, accumulated experience, rational composition of mechanisms, tools and devices; provision of construction regulatory documents, work production projects, flow charts or technological schemes for the entire range of work performed.
1.4.3 In the process of material and technical support of construction, it is advisable to take measures that have a positive effect on the quality of construction and installation work, namely: timely and complete delivery of products and materials required for construction; organization of quality control of supplied products and materials, equipment; ensuring the standard quality of products manufactured at the subsidiary enterprises of the contractor.
1.4.4 When completing construction with qualified personnel, at least the following requirements must be taken into account: the qualifications of specialists must correspond to the technical complexity of the work performed, and training and advanced training programs for specialists must provide for the study of methods for improving the quality of construction and installation work, including progressive technology, new mechanisms, tools and accessories. An analysis of the characteristic defects allowed during the performance of work and taking measures to prevent them should also be carried out.
It is also recommended: creation of conditions for the high-quality implementation of construction and installation works based on real planning, ensuring the rhythmic performance of work; provision of satisfactory living conditions at facilities, especially linear ones, which reduces staff turnover and effective use of a system of material incentives for improving the quality of construction and installation work.
1.4.5 Quality control of construction and installation works should be carried out at all stages of their implementation and is subdivided into the following forms: input; operating; acceptance; inspection.
At the entrance control, the compliance of the design and estimate documentation, equipment, structures, assembly units and materials with the established requirements is checked.
At the same time, compliance with the rules for their transportation, warehousing and storage is also checked.
The composition of inspections, tests and measurements carried out in the process of incoming control, and the procedure for their execution are determined by the relevant instructions. The electrical parameters of the equipment are checked after installation.
During operational control, the technological discipline and quality of work are checked in the process of their implementation and after the completion of a certain production operation. The composition and its procedure are established by operational quality control schemes (SQC), developed directly by the organization - the responsible executor of the work.
An approximate scheme of operational quality control of work is shown in the table.
Table 1.1 - Construction of cable ducts
| Verification steps | Who checks (conditionally) | |||
| 1 | 2 | 3 | 4 | 5 |
| Foreman and brigade members | master | foreman | Foreman in conjunction with technical supervision | |
| Layout of the route for sewerage construction |
||||
| Depth and quality of the trench bottom | ||||
| Quality of pipe laying and sealing of their joints | ||||
| Pit depth for installing viewing devices | ||||
| Quality of installation, assembly and finishing of wells, sealing of pipe entry | ||||
| Checking the quality of work before presenting the cable duct for the delivery of hidden work | ||||
Legend:
All defects identified in the process of operational control must be eliminated before starting to perform subsequent operations.
During acceptance control, the quality of the completed structural elements, individual structures, types of work and objects in general is checked. Interim acceptance of the work performed is carried out by representatives of technical supervision appointed by the customer. Specialists designated by the operating organization may be appointed as representatives of the customer.
1.4.6 Surveillance in kind at intermediate acceptance by a representative of technical supervision together with a representative of the contractor's organization is subject to hidden work, which, when performing subsequent final operations, becomes inaccessible for inspection without opening or other measures. These types of work include: laying of pipelines and construction of wells for cable ducts; laying cables and protective wires in the ground; laying of cables in cable ducts; installation of cable crossings over roads and railways; installation of cable crossings over water barriers; installation of couplings and cable splices; installation of grounding; construction of URP; assembly, rigging and installation of supports and suspension of wires of overhead communication lines.
The representative of the technical supervision of the customer must be informed by the representative of the contractor when, where and what works are being performed, systematically invite to the place of these works to inspect their quality and draw up acts for hidden and other work performed. If the customer's technical supervision representative does not appear at the appointed time, the acts are drawn up by representatives of the construction and installation organization unilaterally with a note of the customer's representative failure to appear and information from the customer's organization.
In the event that the customer's technical supervision representative refuses to sign acts for hidden work due to poor quality work, he informs the customer's and contractor's organization about this for taking appropriate measures. Acts for hidden works by their types, in which the indicators to be checked are indicated, are drawn up according to the current forms.
1.4.7 During the inspection control, a random check of compliance with technological discipline and the quality of construction and installation works is carried out. Inspection control is carried out by commissions appointed by the order of the contractor. The results of the inspection control are formalized by an act of the commission or a report, which is submitted to the official who appointed the inspection for taking action on the conclusions of the commission.
1.4.8 In accordance with the work contract, the contractor at the construction site keeps a work production log from the start of work to its completion. At the same time, the contract, by agreement of the parties, determines the procedure for keeping a journal (for each object separately or as a whole for a construction site, or types of work) and also stipulates the customer's right to control the content of the journal. The customer's requirements regarding the quality of work should be recorded in the journal and carried out by the contractor with a subsequent entry in the journal about the elimination of the noted shortcomings in the performance of work.
In order to exclude poorly performed construction work, a construction company should have a clear construction quality control system. And the main task of which should be - prevention of violations and deviations from PD and TR (design documentation and technical regulations) during the execution of work.
To do this, it is necessary to consistently raise the general level of culture, raise the indicators of the level of mechanization and complex mechanization of construction and installation work, and improve inventory, devices and tools. Responsibility for the quality of construction should be borne by the production and technical personnel of the construction company, from the first manager to the foreman, foreman, as well as workers.
In Russia, the following types of quality control have developed in construction practice:
Incoming control
Technological (operational) control
Intermediate
Acceptance
Incoming control... The quality of buildings and structures primarily depends on the quality of building materials, products and structures. It also depends on the quality of the project. The quality of design documentation is controlled during the state examination process, but in any case, projects must be carefully studied by a construction company, which can detect inconsistencies, make proposals for changes in technology, such control is also called input control. It also includes checking the qualifications of the brigade, in order to determine the possibility of admitting them to work. As well as briefing on the technology of carrying out a particular construction and installation process. The quality of building materials, products is determined by external inspection - checking the size and appearance, as well as their compliance with the accompanying documents. More thoroughly, the quality is checked in construction laboratories by various test methods. At the same time, control can be continuous and selective. The sampling results are applied to the entire batch of the incoming goods. An act is drawn up indicating the defects.
Technological controlcarried out during the production of construction and installation works. It is this type of control that should be considered the main one, since its main purpose is to detect deviations from the design documentation and violation of SNiP, technical regulations and other regulatory documents. The most effective is self-control, when the worker himself controls the quality of his work and does not allow any deviations and violations. The exclusion depends on the qualifications and professionalism of the workers performing this work. High-quality performance of work is the provision of work cards of work processes, as well as special diagrams indicating the additions allowed by the norms. An important condition for self-control is moral and material support. Geodetic control is of particular importance, as part of the PPR, a scheme for geodetic control of the compliance of the structures and parts of the building with their design position is being developed. When installing high-rise buildings, mandatory documents are geodetic schemes for floor control of the accuracy of installation of the structure.
Intermediate controlis carried out upon acceptance of certain types of completed construction and assembly or finished building structures. At the same time, the contractor's gene quality control service takes an active part. The purpose of the interim control is to make sure that the construction process or structural element has been performed with good quality and that the next process can be started. The developer or customer can conclude an agreement with the design organization on designer supervision of construction, for a fee. Designer supervision is carried out in accordance with the schedule drawn up by the customers, it contains the frequency, timing of it, the list of construction and installation works subject to supervision.
One of the ways to ensure the highest quality of construction and installation work (CMP) at the facilities of the enterprise, as well as to monitor compliance with the requirements of the project, building codes and regulations, State standards and technical regulations at a construction enterprise is to introduce quality control of construction and installation work. This allows the organization not only to reduce production costs, but also to become more attractive for both Russian and foreign partners. The main types of quality control of construction and installation works are:
Incoming control
Includes incoming inspection of materials, products, structures and equipment; organized in accordance with the requirements of GOST 24297-87 according to passports and certificates of suppliers. Carried out by Contractors and selectively controlled by the Customer.
Operational control
It is organized in accordance with the requirements of SNiP 3.01.01-85 and SNiPs for specific types of work. Controlled parameters, frequency and methods of control are taken in accordance with the requirements of SNiP. At each site, it is mandatory to keep general work logs and draw up other documents provided for by regulatory requirements, including acts for hidden work.
Geodetic control
Geodetic control is carried out by specialists of the organization in accordance with the requirements of SNiP 3.01.03-84. It is possible to attract specialized organizations under contracts. The customer controls the geodetic reference network and the as-built documentation of the geodetic works carried out by the contractor. The accuracy and volume of geodetic works are determined by SNiP and the project.
Acceptance control
Acceptance control of construction and installation works organized in accordance with the requirements of SNiP 3.01.04-87 and SNiP for specific types of work. Acceptance should be carried out with the participation of authorized representatives of the GASN department and others, if necessary; at the same time, acceptance certificates are drawn up. In the process of acceptance of works, all the necessary tests of networks for ultimate loads are carried out with the registration of confirming acts of the tests carried out.
Inspection control
It is carried out by specialized organizations that have the right to exercise control, according to plans and within the time frame provided for by the Controlling Organizations. At least 3 times during the construction period of the facility, an inspection check of the quality of work is carried out by a commission consisting of representatives of the Customer, contractors and designers.
Laboratory control
Laboratory control is carried out by the construction laboratory during the incoming inspection of building materials as required or at the request of the Customer, when performing structural elements (monolithic concreting, screed, welding, etc.), during the construction of utility networks (grounding, resistance, chemical, bacteriological analyzes, etc.) , upon delivery of the object (thermal conductivity, etc.). Laboratory quality control and metrological services, if necessary, are carried out on a contractual basis with the construction laboratory. Metrological support of construction and installation works is carried out in accordance with GOST 8.002-86 GSI. "State supervision and departmental control over measuring instruments. Basic provisions" and GOST 8.513-84 GSI. "Checking measuring instruments. Organization and procedure". Also, quality control in construction can be carried out in accordance with STO FTSS 06-2004 "Quality assurance systems in construction organizations", which excludes some requirements for document flow presented in GOST R ISO 9001-2001. This standard is the most attractive for foreign partners and investors, as it is focused on the international standard ISO 9001: 2000 and complies with its main provisions. ISO 9001: 2000 is one of the modern standards for the control of the quality management system (QMS) in relation to the performance of the functions of the customer-developer in the design, construction, sale, warranty service, and provides for the following mandatory documents:
- quality document management;
Internal audit;
Analysis by management;
Management of nonconforming products;
Corrective and proactive actions;
Monitoring and measurement of processes and products.
