Construction scheme of super high-rise bored pile?

The construction scheme of super-high-rise bored pile is very important. The scheme is made on the basis of on-the-spot investigation and rational use of professional knowledge by professionals, and every detail is very important. Zhong Da Consulting tells you about the construction scheme of super high-rise bored pile.

1. Overview:

The bored pile is used for the engineering pile of Building No.0 of XX Garden, and the designed pile diameter is φ800. Bored cast-in-place piles are used for enclosure, and the pile diameter is φ850. The concrete grade is C30, and the underwater grade is raised to C35.

The basic engineering quantity is as follows: the engineering pile is φ800mm, the effective length is 50. 1 m, the pile end enters ⑦2b grayish yellow silt layer, and the absolute elevation of the pile end is -54. 15m, with a total of ***499 piles, of which 15 piles are also used as supporting lattice columns; The retaining pile is φ850mm, the effective length is 17m, and the absolute elevation of the pile end is-16.25m, with a total of 259 piles.

2. Construction process flow

Note: Suspended lattice columns only support column piles, including

3. Hard floor construction technology

1. Overview

According to the distribution and pile-forming sequence of engineering piles, combined with the bored pile technology, a certain number of ditch networks and a certain capacity of mud pools with circulation, sedimentation and waste storage functions are set up; Hardening the ground with concrete; Bricks are used to harden the ditch and pool, so that the mud forms a closed circulation system and is discharged in an orderly manner. The problems of mud overflow and site softening are solved, so as to achieve the unity of construction quality, safety, progress, economy and comprehensive benefits of civilized construction of bored piles.

2. Hard floor construction technology

1. On-site hardening procedure and technological process

* Be familiar with the pile bitmap, determine the site elevation, and level the site to determine the hard floor elevation.

* According to the site layout, dig mud pits and mud ditches.

* Discharge temporary pipes.

* site concrete is cast 5~ 10cm, with the label C20.

3. Mud process flow

4. Measurement and positioning technical measures

According to the floor plan of pile position, building sideline and main foundation axis provided by the owner, determine the pile position with theodolite orientation and steel ruler distance according to the floor plan position, and nail each pile position into the ground with steel bars coated with red paint, with the point deviation less than 5 mm ... Then determine the pile position, and submit the re-inspection sheet for the supervision to re-examine and accept.

5. Technical measures for burying lining

Surveyors and engineers are responsible for the embedding accuracy of casing. The casing has a diameter of 950mm and a buried depth of ≯2m, and the deviation between the center axis and the center is ≤10 mm. It is backfilled with clay and tamped by layers. The lining is made of 3mm steel plate, with a height of 1.2- 1.5m, and a reinforcing ring should be set at the top. The diameter of the pile casing should be greater than the pile diameter 100 mm, the pile casing should be buried deeply, firmly and correctly, and the surrounding soil should be backfilled and compacted in layers. The depth of the bottom of the bucket into the original soil is not less than 200mm. The deviation between the center point of the pipe and the actual pile position is not more than 10 mm.

6. Technical measures for pore-forming construction

1. After the drilling rig is in place, the chassis should be padded, and the center of pile position, movable drill pipe and crown block should be on the same vertical line.

2. At the beginning of hole-forming drilling, drill slowly and gently, and circulate mud with a small amount of pump to prevent the hole protector from deviating due to severe vibration of the drill bit.

3. The drilling tool should ensure verticality, rigidity and concentricity, and the diameter of the drill bit must be the same as the designed pile diameter.

4. Correct use of drilling parameters. The stratum lithology in the construction area is mainly cohesive soil and silt. When drilling parameters are selected, the WOB of cohesive soil can be controlled at 10-20kPa and the rotating speed is 20-40r/min. WOB of silt and sandy soil can be controlled at 15-25 kPa, and the rotating speed is 40-70r/min.

5. Correct use of mud performance indicators, positive circulation pore-forming is adopted in construction, and mud performance indicators are controlled as follows:

The performance index density of mud at the injection port is ≤ 1. 15 viscosity18 "-20".

The mud performance index density of discharged pore products is ≤ 1.30, and the viscosity is 20 ″-22 ″.

6 hole cleaning technical measures

Hole cleaning is carried out in two times, and the first hole cleaning is carried out directly after the last hole. During hole cleaning, the drilling tool should be lifted about 20cm away from the bottom of the hole, and the high-density mud of 1.25- 1.30 should be used until there is no slag, and the first hole cleaning is over. The second cleaning is carried out in the reinforcing cage, and the conduit is used after being placed. Low density mud ≤ 1. 15 shall be used for hole cleaning. The conditions for finishing the second hole cleaning shall be controlled in mud density ≤ 1.25, viscosity ≤ 22 "and sediment thickness.

7. Fabrication and installation of reinforcing cage

According to the design drawings, the profile of reinforcing cage is compiled, and the reinforcing cage is processed according to the design requirements and specifications. The length of reinforcing cage is determined according to the length of incoming materials. The blanking should be accurate, the main reinforcement should be straight, and the surface should be free of dirt and corrosion.

There is a special workbench and construction platform to make reinforcing cages to ensure that the reinforcing cages are straight. The annular stirrup is connected with the main reinforcement by spot welding, and the spiral stirrup is connected with the main reinforcement by spot welding at intervals.

The processed reinforcing cage shall be carefully inspected and accepted according to the specifications and design requirements, and the unqualified part shall be corrected, and the qualified reinforcing cage can be lowered into the hole.

The stacking and handling of reinforcing cages should be kept straight to prevent bending and deformation.

When the reinforcing cage is lowered into the hole, it should be placed vertically, aiming at the hole position, slowly and gently, so as not to collide with the hole wall. In case of obstacles, it is not allowed to be forcibly lowered in the lower cage. The reasons should be identified and continued to be decentralized after proper handling.

During wellhead welding, the dirt on the surface of the welding part of the main reinforcement should be removed, and the position of the main reinforcement in the upper and lower cages should be set correctly. The upper and lower cages should be in a vertical state and welded symmetrically on both sides. After the welding is completed, the stirrups at the welding parts should be supplemented, and the installation of the next reinforcing cage can only be carried out after the acceptance.

The installation depth of reinforcing cage should meet the design requirements. After all holes are confirmed to meet the requirements, fix the reinforcing cage so as to locate the reinforcing cage and avoid going up and down when pouring concrete.

Covered electrode for reinforcing steel bars shall have the factory inspection sheet and warranty, and raw materials and welding tests shall be conducted according to the requirements of the regulations.

The main reinforcement of segmented reinforcing cage adopts single-sided welding lap joint, the lap joint length is 10d, and the number of main reinforcement joints in the same section is not more than 50%.

The solder joints shall be firm, and the weld width and stack height shall meet the specification requirements.

In order to ensure the thickness of protective layer, a group of protective blocks are set every 4m in the longitudinal direction of reinforcing cage, with 4 blocks in each group, which are symmetrically distributed.

Reinforcing cage should be installed in the center of the hole, hanging straight and steady, sinking slowly to avoid collision with the hole wall.

After all the reinforcing cages are inserted into the holes, send the reinforcing cages to the predetermined elevation with positioning steel bars in time for hanging and fixing. The false control of cage top should be controlled within100 mm.

8. Technical measures for installation of perfusion catheter

The catheter is a tube with a wall thickness of 3 mm, a diameter of 258 mm and a length of 2.50 mm.

The conduit shall not be bent or sunken, and the joint shall be sealed with sealing ring to prevent water from stopping.

The depth of the catheter into the hole is controlled at about 50 cm from the bottom of the hole.

9. Technical measures for underwater concrete pouring

Underwater concrete pouring shall be carried out within 30 minutes after the second hole cleaning.

According to the design and owner's requirements, choose high-quality commercial concrete. When preparing concrete, the initial setting time should be considered to shorten the pouring time as much as possible.

The slump of construction concrete shall be inspected according to the quality standards required by the regulations, and the slump of pouring concrete is 18~22cm. At the same time, in the grouting process of each pile, 1 group (3 blocks) should be made as required, and the sample of the block should be representative, maintained according to the specification requirements, and submitted for inspection 28 days later.

The design strength grade of pile concrete in this project is C30, and commercial concrete is used for construction. The actual strength grade of concrete should be improved by one grade, namely C35 (or underwater 30). So as to ensure smooth concrete pouring. Commercial concrete adopts flowing concrete, and the slump is controlled at 18~22cm.

During the initial pouring of underwater concrete, the iron wire used to install waterproof bolts in the conduit should be cut off only after enough concrete is poured initially. The waterproof plug is made of rubber bladder.

Underwater concrete pouring should be carried out continuously, and the conduit should be buried below the concrete surface from beginning to end. It is forbidden to lift the conduit away from the concrete surface, and the depth of the conduit buried in the concrete should be 3- 10m, at least not less than 2m. In Qin Ying, the catheter should be removed frequently, and the extubation should not exceed 6m at a time.

Pay attention to control the pouring speed of concrete, especially when the concrete surface rises to the bottom of the reinforcing cage, the pouring speed should be slowed down, and the lifting conduit should be stable, so as to avoid the reinforcing cage floating (floating cage) caused by the excessive impact of unloading or the hook between the conduit and the reinforcing cage.

In the process of pouring, there must be someone who is responsible for measuring the height of the concrete surface and lifting and dismantling the conduit in time. The buried depth of the conduit is 3~ 10m, and it is forbidden to lift the conduit off the concrete surface. The initial pouring amount shall ensure that the buried depth is not less than 2m.

In the process of concrete pouring, the rising surface height of concrete should be determined frequently according to the soaking situation. The reserved height of the concrete column above the top surface of the pile should be controlled at 2-2.5m. ..

Concrete pouring shall be continuous and dense without interruption. At the same time, in the process of pouring, Qin Ying moves the conduits in series to make the concrete filling dense.

In order to ensure the quality of pile head, according to the design requirements, a certain amount of over-irrigation is carried out above the design elevation. Its perfusion filling coefficient shall not be less than 1.05.

After concrete pouring is completed, the steel hanger should be cut off in time, the casing should be pulled out, and the orifice mud and residual concrete slurry should be removed.

10. Main construction equipment

Remarks on varieties, specifications, models, units and quantities

Engineering drilling rig GPS- 15 55*30KW

Pouring platform 55*22KW

Mud pump 3PNL 10 10*22KW.

43×75KW deep mixing pile driver SBJ-II

Mortar pump table 3

Mixing sleeve 3

Welding machine B * 1-3 15F 66*24KW

Overview of the construction scheme of super-high-rise bored pile: according to the distribution and pile-forming sequence of engineering piles, combined with the bored pile technology, a certain number of ditch networks and a certain capacity of circulating sedimentation are set up.

More information about real estate network

Air compressor 3WC-O.9/7A44 * 5.5kW.

Crane QY 12- 16 Unit 2

Sewage truck 8 ton platform 6

Sewage pump NL65A- 16 sets of 22*5.5KW

Theodolite J6 platform 2

S3 grade 1

Catheter Ф 258m 250

1 1. Construction quality control standard

1. The pile length reaches the design length, and the pile diameter is (+50mm, -0mm).

2. The thickness of sediment before grouting after pore formation shall not exceed100 mm. ..

3. The strength, quality and bearing capacity of the pile meet the design requirements.

4. The filling coefficient of pile concrete should not be less than 1 or greater than 1.3.

5. The compressive strength and mathematical statistics evaluation index of concrete block should meet the design and specification requirements.

6. The deviation between the actual pile position and the designed pile position is less than100 mm. ..

7. Vertical deviation of pile hole <1100.

8. Allowable deviation of reinforcing cage fabrication: main reinforcement spacing 10 mm, stirrup spacing 20mm, reinforcing cage diameter 10 mm, reinforcing cage total length 100 mm. ..

12. Quality assurance measures for bored pile construction

In order to ensure the smooth progress of this project on the premise of ensuring the quality and time limit for a project, the following specific rules-based quality assurance measures must be formulated and implemented in a strict quality management system:

1) construction raw material control

All construction raw materials must be purchased from qualified suppliers screened and confirmed by the company. The main material acceptance requirements are as follows:

(1) Acceptance of steel: the grade, variety and diameter of steel (reinforcement) shall meet the design requirements. All steel (rebar) must have a quality certificate. And the second interview of sampling machinery should be carried out according to each batch of no more than 60 tons. You can only use it if you pass the second interview. At the same time, under the welding conditions of the same welder and the same specification, the spot welding of reinforcing cage is also inspected according to the sampling standard of every 300 pieces.

(2) Acceptance of commercial concrete: Commercial concrete must be provided by a concrete supplier who has been audited by the Municipal Building Materials Industry Management Office and issued the Commercial Concrete License. When the commercial concrete comes into the site, the quality certificate of the commercial concrete shall be obtained from the concrete supplier according to the same batch number at the site acceptance. Two tasks should be done well in construction site acceptance. One is slump detection, and unqualified concrete should be returned. Secondly, the concrete test block made on site is taken as the final evaluation basis of the concrete strength of the bored pile unit project. Not less than one set of test blocks shall be made for each pile. Considering the influence of initial setting on pile quality, the time interval between commercial concrete being transported to the site and being transported from the mixing station and put into use should not exceed 2 hours.

2) Control of construction personnel

(1). All managers and constructors engaged in quality-related work must use personnel who have been trained in special functions and skills and passed the examination. On-the-job personnel in important positions such as project manager, builder, quality engineer, safety officer, material engineer, rig operator, welder and steam crane operator must hold relevant certificates.

2. Before starting work, educate all construction personnel and management personnel engaged in quality, organize a quality activity summary appraisal meeting once a week or every ten days, put forward rectification opinions on outstanding problems, and formulate rectification measures.

(3) Quality responsibility should be institutionalized. The quality responsibility system should not only be implemented to the specific person in charge and the operation team, but also reflect a clear scale of rewards and punishments. The quality responsibility system must be posted on the wall for mutual supervision.

3) Construction process control

The construction process control of bored pile is mainly embodied in four concealed engineering projects: hole forming, hole cleaning, fabrication and installation of reinforcing cage and concrete pouring.

The control points are as follows:

(1). Pore formation:

The parameters of hole-forming drilling and the performance index of mud used must be determined according to the results of trial hole-forming. In order to make the parameter selection representative, the number of trial holes should not be less than 2, and the diameter of the hole-forming bit must be the same as the pile diameter. Pay attention to regularly check the wear degree of the drill bit and repair the size in time according to the wear condition.

Generally, the verticality of hole formation is controlled by the stable positioning of drilling rig and the vertical positioning of frame. This stability and verticality must be determined by the trial operation of drilling rig and the correction of special level. It is forbidden to use the method of visual gross estimation.

Hole-forming construction shall be completed continuously at one time, and drilling shall not be stopped without reason. During drilling flow operation, the safe distance between adjacent holes should not be less than 4 times of pile spacing, and the minimum time interval should not be less than 36 hours.

(2). Borehole cleaning:

Hole cleaning must be carried out twice or more. The principle of stopping hole cleaning is: after the first hole cleaning, the feel of mud should be basically free of particles and slag. After the second hole cleaning, the mud in the hole should basically be new mud after replacement, and the mud density, viscosity, sand content and sediment thickness meet the design and specification requirements.

(3) Fabrication and installation of reinforcing cage

The manufacturing dimension deviation of reinforcing cage should be strictly implemented in accordance with the specifications, and eye-catching reinforcing cage manufacturing standard cards should be hung in the on-site processing shed as a reminder.

In order to prevent the reinforcing cage from irretrievable deformation due to careless handling and lifting, the reinforcing cage should be transported and lifted under the condition of multi-point average stress.

On-site reinforcement cage stacking site should be flat, and the stacking height should not exceed 2 floors.

When the reinforcing cage enters the hole, the cage should be installed vertically, and it should sink into the hole smoothly for three times without obstacles. The reinforcing cage should be welded firmly in sections to prevent the cage from coming out.

The elevation data of reinforcement cage depth positioning shall be reviewed and approved by two or more people, and the conformity shall be confirmed by the hole supervisor.

(4). Concrete pouring

Concrete pouring should be carried out within 30 minutes after the second hole cleaning, otherwise, whether it is necessary to clean the hole again should be decided according to the re-measured sediment thickness. The commercial concrete used should have good workability and suitable slump. The initial pouring quantity of concrete shall not be less than 1.5m3, and the initial buried pipe of conduit shall not be less than1.5m. ..

The concrete pouring of each pile shall be carried out continuously, and it is forbidden to lift the bottom of the conduit off the concrete surface during pouring.

Concrete test blocks should be made from the upper, middle and lower sections of each pile and sent to the standard curing room for curing in time. The 28-day test block shall be sent for pressure test, and it shall not be advanced or postponed.

4) Control of inspection and review system

(1). The points caused by the fixed point of pile position, datum axis and leveling elevation in pile foundation construction must be inspected and accepted by the general contractor, the construction and supervision unit or the agent entrusted by one of the three parties on the spot, and can only be used after passing the inspection.

⑵. In the process of construction, the system of three inspections should be improved. After the completion of each working procedure, the construction personnel should first check the construction quality. After the self-inspection quality of the construction personnel is qualified, it will be handed over to the overlapping process team for mutual inspection. After the quality of mutual inspection is qualified, the full-time quality controller will finally accept it. If the third inspection fails, the construction of the next working procedure shall not be carried out.

(3) All concealed works must be accepted by the general contractor, the project supervision unit or the agent entrusted by one of the two parties at the site, and the construction can continue only after passing the acceptance.

(4) The raw materials and finished products that make up the pile body, such as steel bars and commercial concrete, must abide by the strict material quality inspection system when entering the site. The name, origin specification, furnace number, batch number and production date of imported steel, and the strength grade, slump, mix proportion and quantity of imported commercial concrete must be consistent with the corresponding quality certificate submitted.

5]. Re-inspection, re-inspection of steel bars and pressure test of concrete test blocks must be entrusted to the first-level testing qualification unit approved by the Municipal Construction Management Office for testing, and the test report must be audited.

13 safety production and civilized construction management

Safety production needs to formulate necessary safety guarantee measures, but to achieve safety production, someone must implement and maintain these measures, which requires the consciousness of construction personnel and the supervision of management personnel. Therefore, it is very important to formulate the necessary safety management system and implement the necessary safety technical measures to maintain safety in production.

1) safety responsibility system

According to the engineering characteristics and the actual situation of site organization, the safety responsibility system is determined as follows:

(1). Project manager: the first person responsible for the safety of this project is responsible for the overall construction safety.

⑵. Deputy Project Manager: Take direct leadership responsibility for safety production within the production scope, and be responsible for organizing the implementation of various safety production measures and safety production systems.

⑶. Technical responsibility of the project: responsible for the preparation of safety technical measures, safety technical disclosure and safety technical education, and responsible for safety production.

⑷. The builder: directly responsible for the safety in production within the construction scope, implementing specific technical measures for safety in production, supervising and inspecting the implementation, proposing rectification opinions, checking the rectification results, and proposing punishment opinions as needed.

5]. Safety officer: responsible for the safety management, supervision and inspection of construction, and exercising veto power over safety production. Put forward rectification measures and opinions on construction safety hazards, and supervise and inspect the rectification results. Responsible for handling and reporting safety accidents.

[6]. Process person in charge: responsible for the safety production of each construction process, checking and implementing safety production measures, responsible for the safety disclosure of handover posts in each process of commuting, and directly responsible for the safety production of this process.

2) Safety education system

(1). Enter the site to educate all employees.

2. Conduct regular safety awareness education, post education for new workers, and combine education and training of various safety operation procedures.

(3) Conduct safety technical disclosure for electricians, welders, riggers, steel bar workers, grouting workers, drillers and ordinary workers respectively, and conduct safety disclosure education for handover posts to and from work.

3) Safety facilities acceptance and listing system

According to the construction organization, super high-rise bored piles are used as safety facilities. Overview of construction scheme: according to the distribution and pile-forming sequence of engineering piles, combined with bored pile technology, a certain number of ditch networks and a certain circulating sedimentation capacity are set up.

If you need more information, you can equip the real estate e-net table according to the construction needs. In order to ensure that the quantity, quality, location and performance meet the requirements of construction safety regulations, the safety management department and power department of the company must review the connection, grounding and protection devices of various parts of construction facilities according to special procedures, conduct trial operation and complete all acceptance procedures before putting them into construction.

4) Safety inspection system

(1) Regular inspection: once every half month. The inspection contents include four aspects: safety awareness, safety system, safety measures and potential safety hazards. By the engineering department in conjunction with the construction department heads.

2. On-site self-inspection: once a week. The contents of the inspection are unsafe hidden dangers and unsafe factors. Organized and implemented by the project manager.

⑶. Irregular inspection: determined according to the actual situation of the project. The inspection content is the outstanding unsafe problem, which is organized and implemented by the safety officer.

5) Safety technical measures

(1). Safety personnel, welders, electricians, crane drivers, steam crane drivers and other special types of work must hold relevant certificates to prevent unlicensed operation.

2. The construction site to post hanging eye-catching safety propaganda slogans, signs.

(3) Before construction, the project manager shall organize safety inspection, and the project can only be started if it is qualified.

(4) For overhead laying of on-site cables, all kinds of electrical controls must be provided with leakage protection devices.

5]. The repair of electrical lines and construction machinery with electricity operation should be carried out without electricity, and warning signs should be hung.

[6]. You must wear a safety helmet when entering the construction site, and fasten your seat belt on the tower.

Once. The exposed transmission system must have a protective net cover.

Existence. Always check the safety and firmness of various transmission, lifting, electrical appliances, mechanical systems and key parts such as boom, lifting rope and hook. And eliminate hidden dangers in time.

14 civilized construction

(1). Machine builders should be dressed neatly, wear work clothes and safety helmets.

2. The site to do civilized construction propaganda, should have eye-catching publicity slogans.

(3) Pay attention to hygiene, and the canteen and dormitory meet the hygiene standards.

(4) Comply with the relevant regulations of the departments of city appearance, transportation, health and environmental protection.

5]. Reasonable layout, strict management, do a good job in civilized construction on site.

[6]. It is forbidden to take the sludge out of the vehicle yard.

Once. Dredge the drainage ditch and mud circulation channel to prevent mud overflow and water accumulation in the site, so as not to affect the site cleaning.

Existence. Do a good job of backfilling the upper part of the borehole and transporting the residual soil, and the construction site must be cleaned up in time.

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