The construction quality of steel pipe piles is related to the stability of buildings, so some details must be paid attention to during the construction of
steel pipe piles. Precautions for the construction of steel pipe piles mainly include:
1. The steel pipe pile needs to be measured and set out before construction, which needs to be carried out by professional surveyors. After all the axes and pile positions have been laid out, the construction should be reviewed by the supervisor before construction can begin.
2. After the pile driver is in place, the pile frame should be adjusted first to ensure that the pile frame is vertically stable.
3. For steel pipe piles to be hoisted and driven, first check whether the quality of the pile body meets the requirements of the specification, draw a length mark on the pile body in meters, and mark the length of the pile from bottom to top, to observe the depth of the pile into the soil And record the hammering number per meter of pile sinking.
4. After the steel pipe piles are aligned in place, they should be straightened repeatedly on both sides of the front side with a line dropper, and the hammer, cap, and pile should all be on the same straight line.
5. During the driving process, when the pile body deviates, it cannot be corrected forcibly by machinery, and it is not suitable to correct it while driving. Try not to correct the deflection within the allowable range of the code to prevent cracking of the pile body; if the verticality deviation is found to be greater than the code requirement, first find out the reason, pull out the pile section, and backfill the pile hole with sand. After that, hit the point again.
6. When the steel pipe pile needs to be extended and the pile head sinks to 500 mm-800 mm above the ground, the hammering can be stopped and the previous pile can be connected. When connecting the piles, a guide hoop (pile barge) should be set at the pile head of the lower section so that the upper section piles can be in place, and the upper and lower sections of the pile should be kept straight, then the pile barges should be removed, and the upper and lower end plates should be cleaned with a wire brush. Do the welding.
7. When driving piles in thick sandy soil and silty clay layers, it is advisable to drive one pile continuously until the hammer is closed. Because piling in this kind of soil layer has a strong soil consolidation force, if the pile is driven after a period of rest, due to the consolidation of the soil and the recovery of the soil, the pile cannot be driven. If it is forced to be driven, it will appear The phenomenon of smashing the pile head.
8. When the steel pipe pile hits the bearing layer required by the design or reaches the penetration value required by the design, the hammer can be received. After the steel pipe pile is hammered, the actual measurement record shall be made in time, and the verticality deviation of the pile shall be measured with a line drop, and it shall be filled in according to the east, south, west, north directions and their percentage values; Use a hammered line or light to detect into the hole, and compare it with the length of the pile, and report any problems found in time.
9. When the top of the pile is driven close to the ground and the pile needs to be delivered, the verticality of the pile should be measured and the quality of the pile top should be checked before the pile is delivered. The pile delivery device should match the size of the steel pipe pile. A sack or cardboard should be added between the pile heads of the pipe piles as a cushion. To ensure the single pile bearing capacity of the steel pipe piles, the penetration value of the conveying piles should be tightened, generally, 80% when the piles are not conveyed. %.
