Experimental Study on Sedimentation Characteristics of Foundation Piles under Super-Large Tonnage Static Load Test

Abstract

Based on the combination of theoretical analysis and site test, regard-ing to sedimentation problem of super-large tonnage static load test, this paper studies pile sedimentation, lateral friction resistance of pile, pile tip resistance, rel-ative displacement of pile and other physical and mechanical changes characteris-tics. The results show that the Q-s curve of the pile shows a slow change charac-teristic, and the rebound rate of the test pile is 29.26%. The sedimentation curve of the pile gradually changes from the elastic phase to the plastic stage with the increase of the load. With the increase of the applied load at the tip of the pile, the variation curve’ slope of the axial force of the pile shaft gradually decreases, and the lateral friction resistance of the shallow soil show trends of gradually de-crease compared with deep soil, while the relative displacement of pile top and bottom is gradually increasing. The resistance and displacement of pile tip also show a significant proportional relationship. The lateral friction resistance of silty clay has a greater effect on the pile shaft. With the further increase of the depth, the axial force of the pile shaft is obviously decreasing, the decay speed is faster, the pile tip resistance is gradually increased, showing a distinct feature of the fric-tion pile. In this paper, the calculation and analysis procedure of large diameter bored pile is proposed. The nonlinear sedimentation problem of the pile and the surrounding medium is simulated by nonlinear treatment module of the finite element method in the software. The prediction results are basically the same as those of the on-site monitoring results, and the overall prediction accuracy reach-es 88.79%.