Precautions for steel pipe pile construction
1. Before steel pipe pile construction, it is necessary to measure and set up the line, which needs to be carried out by professional surveying personnel, and all the axes and pile positions are set up.
2. After the pile machine is in place, the pile frame should be adjusted first, and the pile frame body is required to be 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, and 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 record the number of hammer blows per meter of pile sinking.
4. After the steel pipe piles are aligned and in place, they should be repeatedly straightened with a wire drop on both sides of the front side. Strive to make the hammer, cap, and pile in the same straight line. Partial driving is strictly prohibited.
5. In the process of driving, when the pile body is skewed, it is not allowed to use a machine to forcibly correct the deviation, and it is not advisable to perform the correction while driving. The deflection should not be corrected within the allowed range of the specification to prevent the pile from cracking; if the verticality deviation is found to be greater than the specification, the reason must be found first, the pile section shall be pulled out, and the pile hole shall be backfilled and compacted with sand After that, hit the points again.
6. When the steel pipe pile needs to be extended and the pile head sinks 500mm-800mm above the ground, the hammering can be stopped and the previous section of the pile can be connected. When connecting piles, a guide hoop (pile clamp) should be set at the head of the lower section pile so that the upper section pile should be in position. The upper and lower pile sections should be kept straight. Then remove the pile clamp, clean the upper and lower endplates with a wire brush. Perform welding.
7. When driving piles in a thick sandy soil or silty clay layer, it is advisable to continuously drive one pile at a time until the hammer is closed. Because piles are driven in this kind of soil, the soil has a strong consolidation force. If the pile is driven after a period of rest, the consolidation of the soil and the recovery of the soil will cause the pile to fail to be driven. If forced to be driven, it will appear The phenomenon of broken pile heads.
8. The hammer can be retracted when the steel pipe pile reaches the bearing layer required by the design or reaches the penetration value required by the design. After the pipe pile is hammered, the actual measurement record shall be made in time, and the verticality deviation of the pile shall be measured by the line drop, according to the east, south, west, and north directions and their percentage values; if there is doubt, the pile number shall be used Detect the heavy hammer line of light into the hole, and compare it with the length of the piles, and report the problem 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. Sack or hard paper should be added as a cushion between the pile heads of pipe piles. To ensure the single pile bearing capacity of steel pipe piles, the penetration value of the piles should be tightened. Generally, the penetration value is 80% when the piles are not supplied. %.
After understanding the operation of these steel pipe piles, we have a more in-depth understanding of the correct use of steel pipe piles, which is also convenient for our follow-up work.