The construction quality of steel pipe piles is related to the stability of the building, so some details must be paid attention to during the construction of steel pipe piles. The main precautions for steel pipe pile construction are:
1. Before the construction of steel pipe piles, it is necessary to measure and lay out the lines, which needs to be carried out by professional surveyors. After all the axis lines and pile positions are laid out, the construction should be started after the supervisor has reviewed them.
2. After the steel pipe pile machine is in place, the steel pipe pile frame should be adjusted first to ensure that the steel pipe pile machine frame is vertical and stable.
3. For the pipe piles to be hoisted and driven, first check whether the quality of the steel pipe pile body meets the requirements of the specifications, draw length marks in meters on the steel pipe pile body, and mark the length of the steel pipe pile from bottom to top, to observe the depth of the steel pipe pile into the soil and record the number of hammer blows per meter of pile sinking.
4. After the steel pipe pile is aligned and in place, it is necessary to use a plumb line to repeatedly align it on both the front and side sides, and strive to make the hammer, cap, and pile in the same straight line. It is strictly forbidden to hit it off-center.
5. During the injection process, if the pile body is tilted, it cannot be corrected mechanically, nor should it be corrected while injecting. If the deflection is within the allowable range of the specification, try not to use the frame to correct it to prevent the pile body from cracking; if it is found that the verticality deviation is greater than the specification requirements, first find out the cause, pull out the pile section, backfill the pile hole with sand and tamp it, and then re-inject it.
6. When the steel pipe pile needs to be extended and the pile head sinks to 500 mm-800 mm above the ground, you can stop hammering and connect the previous pile. When connecting the piles, a guide hoop (barge pile card) should be set at the head of the lower pile so that the upper pile should be in place. The upper and lower pile sections should be kept straight, and then the barge pile card should be removed, and the upper and lower end plates should be cleaned with a wire brush before welding.
7. When driving piles in thicker sand and silty clay layers, it is advisable to drive a pile continuously at one time until the hammer is stopped. Because the consolidation force of the soil is large when driving piles in this type of soil layer, if the piles are driven again after a period of rest, the consolidation of the soil and the recovery of the soil body will cause the piles to fail to be driven in. If the piles are driven forcibly, the pile heads will be broken.
8. When the steel pipe piles reach the design bearing layer or the penetration value required by the design is reached, the hammer can be withdrawn. After the steel pipe piles are driven, the actual measurement records should be made in time, and the vertical deviation of the piles should be measured with a plumb line, and the east, south, west, and north directions and their percentages should be filled in truthfully; for suspected pile numbers, a heavy hammer line or light should be used to detect the inside of the hole and compare it with the length of the piles. Any problems should be reported in time.
9. When the pile top is driven close to the ground and needs to be driven, the verticality of the pile should be measured and the quality of the pile top should be checked before driving the pile. The pile driver should match the size of the steel pipe pile. Gunny bags or cardboard should be added as a cushion between the pile driver and the head of the steel pipe pile. To ensure the single pile bearing capacity of the steel pipe pile, the penetration value of the driven pile should be tightened, generally 80% of the penetration when no pile is driven.
Post time: Dec-19-2024