What should be paid attention to in the construction of steel pipe piles

The construction quality of the steel pipe pile is related to the stability of the building, so some details must be paid attention to during the construction of the steel pipe pile. The main points for attention in the construction of steel pipe piles are:

1. Before the construction of the steel pipe pile, it is necessary to measure and lay out the line, which needs to be carried out by professional surveyors. After all the axes and pile positions are laid out, the construction should be reviewed by the supervisor.

2. After the pile driver is in place, the pile frame should be adjusted first to ensure that the pile frame body is vertical and stable.

3. For the steel pipe pile to be lifted 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 the bottom to top, to observe the depth of the pile and its depth. Record the number of hammer blows per meter of pile sinking.

4. After the steel pipe piles are aligned in place, use the line drop to align them on both sides of the front side repeatedly, and try to make sure that the hammer, cap, and pile are all on the same straight line, and it is strictly forbidden to hit them sideways.

5. During the driving process, when the pile body is skewed, it cannot be forced rectified with machinery, and it is not suitable to rectify at the same time. If the deflection is within the allowable range of the specification, the frame should not be corrected as much as possible to prevent the pile body from cracking; if it is found that the deviation of the verticality is greater than the specification, the cause should be found first, the pile section should be pulled out, and the pile hole should be backfilled and tamped with sand. After that, hit the point again.

6. When the steel pipe pile needs to be lengthened and the pile head sinks to 500mm-800mm above the ground, the hammering can be stopped and the previous pile can be connected. When connecting the piles, a guide hoop (pile clip) should be installed at the head of the lower section of the pile so that the upper section of the pile should be in place, and the upper and lower pile sections should be kept straight, then remove the pile clip, and clean the upper and lower endplates with a wire brush. Weld.

7. When driving piles in thicker sandy soil and silty clay layers, it is advisable to continuously drive one pile at a time until the hammer is closed. Because piling in this type of soil layer, the soil consolidation force is large. If the pile is driven after a period of rest, the pile cannot be driven due to the consolidation effect of the soil and the recovery of the soil body. The phenomenon of smashing the pile head.

8. When the steel pipe pile is driven to the bearing layer required by the design or reaches the penetration value required by the design, the hammer can be retracted. After receiving the hammer of the through-steel pipe pile, the actual measurement record should be made in time, and the verticality deviation of the pile should be measured with a line drop. The heavy hammer line or light is detected in the hole and compared with the length of the pile, and any problems should be reported in time.

9. When the pile top is driven close to the ground and the pile needs to be sent, the verticality of the pile should be measured and the quality of the pile top should be checked before the pile is sent. The pile feeder should match the size of the steel pipe pile. Sacks or cardboard should be added between the pile heads as a cushion. To ensure the bearing capacity of a single pile of steel pipe pile, the penetration value of the pile should be tightened, which is generally 80% of the penetration when the pile is not sent.