U-shaped steel sheet pile construction refers to the construction process that uses steel sheet piles to reach the role of foundation pit support during the construction process. Steel sheet pile construction is used in permanent buildings such as docks, rocks, fixed, breakwaters, diversion dikes, buoys, docks, sluices, diversion pipes, foundations, impervious walls, retaining walls, foundations, etc., and excavation of retaining walls, Soil and sand collapse prevention boards, temporary revetments, cofferdam projects, temporary central islands and other temporary structures are often used in the process. Domestic construction is done by professional construction companies, such as Jianji Group and Dongguan Congshulin Building Materials.
Before piling, check the steel sheet piles one by one, and remove the steel sheet piles with rusty and severe deformation of the connection lock. Those who fail to pass can only be used after repairing. Apply grease to the lock of the steel sheet pile to facilitate driving in and out. In the process of inserting and driving, measure and monitor the slope of each pile at any time to not exceed 2%. When the deflection is too large to be adjusted by the aligning method, pull it out and hit again. First use a crane to hoist the steel sheet pile to the point where the pile is inserted to insert the pile. When inserting the pile, the lock must be aligned, and the pile cap shall be put on and hammered lightly every time a piece is inserted. In the piling process, to ensure verticality, two theodolites are used to control in two directions. In order to prevent the displacement of the center plane of the lock, a clamping plate is set at the lock of the steel sheet pile in the direction of pile driving to prevent the displacement of the sheet pile. At the same time, the position of each plate is calculated in advance on the purlin, so that it can be checked and corrected at any time. The steel sheet piles were driven in several times. The first time they were driven from 20m to 15m, the second time to 10m, and the third time to the height of the guide beam. After the guide frame was removed, the fourth time was driven to the design elevation. When piling, start to set the driving position and direction of the first and second steel plates to ensure accuracy, and measure every 1m of driving. Use U-shaped steel piles to place vertically or insert the steel sheet pile locks into the locks of adjacent piles. After the piles are stable, correct and vertical, then vibrate and sink. Every time the steel pile sinks about 1 to 2 mm, stop the vibration to check the verticality of the pile and correct the deviation in time. In order to strengthen the overall rigidity of the steel sheet pile wall, a purlin is arranged along the full length of the steel sheet pile wall. The purlin is composed of channel steel or angle steel, and is fixed to the original steel pipe anchor rod by a tie rod. The tie rod is composed of two Φ25 steel bars. Welded on the steel pipe anchor rod. For the sake of safety, another channel steel or angle steel is used as angle bracing on the five corners of the steel sheet pile wall.
After the foundation pit is backfilled, the steel sheet pile should be removed for repeated use. Before removing the steel sheet pile, the sequence of the pile extraction method, the time of the pile extraction and the soil hole treatment should be carefully studied. Otherwise, due to the vibration of the pile pulling and excessive soil with the pile pulling, it will cause ground settlement and displacement, which will bring harm to the underground structure that has been constructed, and affect the safety of adjacent original buildings, structures or underground pipelines. It is very important to try to reduce the soil with which the pile is pulled out. At present, irrigation and sand irrigation are mainly used. First use the pile driver to clamp the head of the steel sheet pile and vibrate for 1min~2min to loosen the soil around the steel sheet pile, produce "liquefaction" and reduce the frictional resistance of the soil to the pile, and then slowly pull up.
