Why study bored piles? What is the necessity of research?

After passing the self-inspection, each construction process shall be submitted to the technical director of the project department for inspection, and then submitted to the supervision and inspection by the project department. Only after passing the supervision and inspection can we enter the next working procedure. The inspection procedure is as follows:

(1) Check the embedment of liners (including embedment depth, embedment deviation and inclination, etc.). )

⑵ Check the performance (specific gravity, viscosity and sand content) of the newly prepared mud, and fill in the mud test record.

(3) Conduct conduit connection and water tightness test before pouring pile.

(4) After the rig is installed, report it to the technical director of the project department for inspection (rig stability, centering, leveling and inclination deviation, etc.). ).

5] The construction team shall check the mud indicators during drilling and fill in the mud test record.

[6] When drilling, the construction team should fill in the drilling record form and the engineering geological checklist and submit them to the project department in a unified way.

Once after checking the aperture, hole depth and inclination.

Being after cleaning the hole, check the sediment thickness and mud index at the bottom of the hole.

Levies reinforcing cages are inserted into pile holes in sections for welding inspection.

⑽ Fill in the concrete pouring record.

Second, the technical requirements

(1) construction preparation

1, level the site, remove sundries, and tamp the backfill soil;

2, build by laying bricks or stones mud pool, sedimentation tank, pulping pool, prepare qualified clay;

3. Connect water and electricity;

4. The liners should be dug and buried, and the periphery of the liners should be compacted. The diameter of the pile casing should be 0.2m larger than the designed pile diameter, the deviation between the center of the pile casing and the center of the pile position should be less than 5cm, and the inclination of the pile casing should be less than 65438 0%.

5. Mud index

(1), specific gravity:1.05 ~1.15;

(2) Viscosity: the viscosity of mud entering the well is 16 ~ 22s in general, and19 ~ 28s in loose and easy-to-collapse formation;

(3) Sand content: fresh mud should not be greater than 4%;

6. All performance indicators should be tested after pulping. During drilling, the specific gravity, sand content and viscosity of mud should be tested at any time, and the mud test record form should be filled in.

(2) Drilling construction

1. When installing the drilling rig, the underframe shall be horizontal, stable, without displacement and sinking. The deviation between the center of turntable and the center of pile position shall not be greater than 5cm. The centers of drill bit, crown block and rotary table should be on the same vertical line to keep the rig vertical. After the drilling rig is in place, it shall be inspected by the technical director of the project department.

2, drilling tool connection should be vertical, the initial drilling speed should not be too fast, the landing bit speed should be uniform.

3. During drilling, test the mud performance index every hour and fill in the mud test record. And pay attention to keep the mud height in the borehole.

4, often pay attention to observe whether there is any crack on the ground near the hole position or whether there is any change in casing, and whether the drilling rig is inclined. Check the rig level every 2 hours.

5, strictly abide by the operating rules, pay attention to every small link.

6, drilling should be a hole, shall not stop halfway. After drilling reaches the design depth, check the hole position, bit wear, hole depth and hole shape, and the hole position deviation shall not be greater than 10cm, and fill in the drilling record form according to the specification requirements.

7. The construction team is responsible for filling in the engineering geological checklist, collecting and sorting out the collected soil samples and submitting them to the project department. Soil samples shall be stored in wooden cases, and the pier hole position, borrow time and borrow depth of each soil sample shall be indicated (if the geological conditions are inconsistent with the design, it shall be reported to the project department for inspection). The construction team is required to take a soil sample every 1m, and take a soil sample every 0.5 m if there is stratigraphic boundary.

7. On-site disclosure of drilling depth.

(3), aperture detection:

1. Before drilling, make cage hole detector according to the designed pile diameter. Its outer diameter is not less than the design pile diameter, and its length is 4 times of the design pile diameter. The length of the two inverted cones of the leak detector is 0.5m. ..

2. When testing, report to the technical director of the project department for inspection. When lifting the hole inspector, its center is consistent with the center of the hole and the lifting wire rope. If the hole tester is blocked when entering the hole, necking or hole collapse may occur, and the hole should be re-drilled or swept to restore the hole diameter.

(4), hole cleaning

1. After the elevation of the bottom of the hole meets the design requirements, the hole shall be cleaned immediately after passing the supervision inspection. The hole cleaning method is to change the slurry. When pumping slag or mud to suck mud, clean water or fresh mud should be injected into the hole in time to keep the water level in the hole and avoid hole collapse. The hole cleaning time of mud replacement method shall be subject to the mud performance meeting the design requirements. (The settlement thickness of friction piles should be equal to or less than 20cm, and that of cylindrical piles should be equal to or less than 10cm). After confirmation, the drill bit can be removed and the next working procedure can be constructed.

2. When cleaning holes, it should be checked and confirmed by the project department, and reported to the supervisor for inspection and visa concealment.

3. During hole cleaning, keep the water level in the hole higher than the groundwater level 1.5 ~ 2.0m to prevent hole collapse.

4. Before pouring concrete, carry out secondary hole cleaning, turn the sediment, and then immediately pour underwater concrete.

5, shall not be used to deepen the hole bottom instead of hole cleaning.

Control requirements of hole-forming error of bored pile

Allowable error of serial number item

1 50 mm in longitudinal direction of hole center

Transverse 100 mm

2 dip angle 1%

3 aperture is not less than the design aperture

4 hole depth +500mm

0 mm

(5), reinforcing cage production and installation

(See Visa Disclosure Form 003)

(6), pouring underwater concrete

1. The reinforcing cage inserted into the holes in sections shall be kept straight and welded according to the requirements of specifications. Reinforcing cages should be fixed before pouring concrete to prevent floating cages from appearing when pouring concrete.

2. When pouring the first batch of concrete, in order to ensure that all the water in the conduit can be squeezed out and meet the needs of the initial buried depth of the conduit (1 ~ 3m).

3. The catheter should be tested and pressure tested before use, without leakage, and numbered and calibrated from bottom to top. When the catheter extends into the hole, it should be 200 mm to 400 mm away from the bottom of the hole.

4. After the first batch of concrete is poured, it should be poured continuously, and the interruption time should not exceed 30 minutes, and the interval of removing the conduit should be shortened as much as possible. In the process of pouring, the position of the concrete surface in the hole is detected with a sounding hammer every once in a while, so as to adjust the buried depth of the conduit in time. Generally speaking, the buried depth of the conduit is controlled at 2-6m.

5. In the process of concrete pouring, strictly control the quality of concrete, consider the slump loss caused by concrete transportation and weather, and detect the slump of concrete at any time to ensure that the slump is controlled at 18cm-22cm, and resolutely do not use it if it does not meet the requirements.

6. The underwater concrete pouring surface shall be higher than the design elevation of the pile top1.0m..

7. During pouring, the construction team is responsible for filling in the underwater concrete pouring records.

8, the whole perfusion process, submitted to the project department, head of quality supervision.

(7), bored pile quality inspection and test

During concrete pouring, at least 3 groups of concrete test specimens shall be made for each pile. After the foundation pit excavation is completed, the concrete at the pile head is chiseled to the design elevation, and the nondestructive testing test of pile foundation is carried out according to the specifications and the requirements of the owner.

Second, the safety requirements

1. In the construction, the division of labor shall be clearly defined, and unified responsibility shall be taken for safety production. Each drilling rig must designate a construction leader (or team leader) to carry out the construction in strict accordance with the design requirements and specifications to prevent personal injury and quality accidents.

2. Before spudding, all kinds of machines and tools must be overhauled and put into trial operation, so that they are in good normal operation, and they should be overhauled and maintained regularly. Electrical appliances must be installed and maintained by full-time electricians and marked. It is forbidden to go to work after drinking or drinking at work.

3. All personnel entering the construction site must wear safety helmets according to the regulations, abide by the rules and obey the instructions.

4. Participate in the construction personnel should be familiar with the safety operation procedures of this type of work, stick to their posts, and it is forbidden to operate after drinking. Electricians, welders, concrete workers, riggers, steel workers and other special types of work must receive special training, master the operation requirements, strictly implement the safety operation procedures of this type of work, and must carry relevant certificates (or copies) with them for future reference.

5. Crane drivers and riggers must hold relevant certificates. Do not leave your post at work, do not leave your post on the way to lifting heavy objects, and drivers are not allowed to change operating procedures and methods without authorization. When lifting heavy objects, it is forbidden to collide with electrical switches and various control devices. During crane operation, it is forbidden to stand under the boom and within the radius of rotation.

6. When working at night, ensure adequate lighting. Open flame lighting is strictly prohibited on the construction site. Flammable materials such as oil must be kept away from fireworks and equipped with corresponding fire control facilities.

7. The switch box must be equipped with a leakage protector, which should meet the requirements of national industry standards. It is forbidden to pull and connect randomly, and the high-voltage distribution room shall be clearly marked to prevent electric shock accidents.

8. The installation methods of various electrical equipment operation and leakage protection devices are not allowed to be changed at will, especially for the floodlights on the construction work surface, the installation work is not allowed to be sloppy at all, and there can be no leakage to ensure safety. All electrical equipment that is easy to collide should be equipped with protective covers or fences to prevent the danger of collision.

9. Electricians strictly abide by the relevant safety precautions and technical operation procedures, conscientiously implement the system of succession, and it is strictly forbidden to go to work after drinking, arrive late and leave early, and take off the post.

10. Sealed cables are used for transmission lines, and bare wires and wires with poor insulation are strictly prohibited.

1 1. In order to ensure the safety of electricity consumption, all electrical equipment buildings that may be injured by electric leakage or easily struck by lightning should be equipped with grounding or lightning protection devices, and an inspection and maintenance system should be formulated to inspect electrical equipment regularly.

12. When the drilling rig is installed, the frame should be horizontal and stable, and displacement or sinking is not allowed.

13. The rig should be parked smoothly, and the foundation where the rig is parked should be reinforced if necessary. Wire ropes used on drilling rigs should be inspected frequently to eliminate potential safety hazards. The construction shall be carried out in strict accordance with the operation rules of drilling rig and the construction technology of bored piles.

14. When drilling, the drilling speed shall not be too fast or suddenly changed, and the soil in the hole shall not be accumulated around the drilling.

15. Rig operators must operate in strict accordance with the mechanical operation procedures. During drilling, always check whether the connecting bolts of drill pipes are firm, and reinforce them in time when problems are found.

16. After stopping drilling, the drill bit should be safely placed outside the hole and the orifice should be covered and protected.

17. Safety fences must be set around the mud pool of bored piles, and obvious signs should be made to prevent construction workers and pedestrians from accidentally falling into the pool. Bored piles must be compacted, backfilled or protected.

18. When mud is transported out and concrete enters and exits the construction site, traffic protection boards should be set up, and full-time security officers and traffic assistants should be set up.

19. If the hole level is obviously abnormal during drilling, such as the sudden drop of water level in the hole or the sudden serious collapse around the casing, the construction personnel should immediately evacuate the construction site. When welding reinforcing cage, operators should have necessary protective articles.

20. The person who measures the hole depth must wear a seat belt and be protected by special personnel.

2 1. The steel wire rope for hanging drill must be soft and high quality, free from dead bending and broken wires, and the safety factor should not be less than 12. The connection between the wire rope and the drill bit must be firm. When the main rope and the drill wire rope overlap, the diameters of the two ropes should be the same. The twisting direction must be consistent.

22. Drill hoist, wire rope, etc. Use should be properly equipped, and must be checked regularly; Rectify in time when problems are found.

23. When the lifting bit approaches the bottom edge of the casing, it must slow down and lift smoothly.

24. In the process of on-site oxygen cutting, oxygen cylinders and acetylene cylinders must be placed separately in accordance with relevant regulations, and the spacing shall not be less than 5 meters. It is forbidden to expose to the sun.

Three, environmental protection and civilized construction requirements

1. The drilling rig, generator, electric welding machine and steel bar processing machinery at the site must have safe operation procedures and carry them out seriously.

2. When the machine is overhauled, the thick plastic cloth is placed on the bottom to isolate the ground, and the oil is connected with a container to prevent oil pollution.

3. In the process of drilling and pouring concrete, mud should be discharged in time to keep the construction site clean, so that relevant personnel can check it at any time.

4. The site planning is reasonable, the materials are neatly stacked, the site management is orderly, the site roads are smooth, there is no water and potholes, and the electrical lines and distribution boxes are laid neatly and regularly.

5. Do a good job in the environmental sanitation, food hygiene and drinking water hygiene of the resident, and disinfect regularly.

Disclosure reviewer

Date at the bottom of receipt

Mud test record

project name

Pier pile number

Mud raw materials of construction unit

Mud indicator for measuring time test items

Remarks on annual, monthly and daily specific gravity, viscosity and sand content

Note: The test items should be filled in as follows: (1) Pulping outside the hole; (2) making mud in the hole; (3) process inspection; (4) Hole cleaning inspection

Construction leader and operator:

Drilling record sheet

project name

Purnot. Pileno Start and end dates Year Month Day.

Drilling method for designing pile diameter and hole depth

Design bit form, hole bottom elevation and casing top elevation.

Design pile top elevation bit diameter

Drilling depth of man-hour project (m) Description of geological conditions of hole bottom elevation

Start and stop this iteration

Note: (1) Draw the pile position in the remarks column; (2) Record the hole-forming inspection.

Records: construction leader: engineering geological checklist

project name

Purnot. Pileno Start and end dates Year Month Day.

Design hole bottom elevation and casing top elevation (or rig platform elevation)

Design pile top elevation bit diameter

Drilling depth (m) Geological sampling number

This repetition

Record: person in charge of construction:

Underwater concrete pouring record form

project name

PierNo hole bottom elevation. Where's Pileno? ..

Elevation of hole bottom before grouting (m) design elevation of pile top (m) elevation of reinforcing cage bottom (m)

Concrete quantity per slab (m 3) and design concrete quantity (m3) at the top elevation of the pile casing.

Measuring time concrete surface elevation (m) bottom elevation (m) buried depth (m) matters needing attention when pouring concrete.

Cumulative number of catheter sleeves (m 3)

Note: (1) Draw a schematic diagram of the pile location in the remarks column; (2) When using casing drilling rig, the elevation of casing mouth and casing buried depth are increased.

Record: person in charge of construction: