边载作用下隔离桩受力特性及隔离效果研究
Mechanical characteristics and isolation effects of isolated piles due to side loading
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摘要: 以港珠澳大桥海底沉管隧道基础沉降控制研究为科研背景,为研究岛头高边载作用下隔离桩受力特性及其隔离效果,进行了4组室内模型试验。试验结果表明:隔离桩在边载作用下呈典型的被动桩受力特性,且隔离桩桩身最大弯矩随着长度的增加而增加;因隔离桩的隔离作用,每级边载作用下邻近桩基的桩身最大轴力较无隔离桩情况下减小10.5%左右,同时,桩身最大正弯矩和最大负弯矩分别减小20%和25%左右;邻近桩基桩身最大轴力减小幅度随着隔离桩长度的增加而减小,但桩身最大正弯矩减小幅度随着隔离桩长度的增加而增加,弯矩隔离效果较为显著。Abstract: Based on the settlement control of the immersed tube tunnel of Hong Kong-Zhuhai-Macao Bridge, laboratory model tests are performed to study the bearing behaviors and isolation effects of isolation piles under a large side loading in the island edge. The results show that the mechanical properties of isolation piles are similar to typical characteristics of passive piles, and the maximum bending moment for isolation piles becomes larger as the length increases. The maximum axial force of the adjacent piles decreases by 10.5% under each level of side loading due to the isolation effects of isolated piles. At the same time, the maximum positive and negative bending moments decrease by 20% and 25%, respectively. The decreasing degree for the maximum axial force of the adjacent piles decreases as the length of isolation piles increases. However, the decreasing degree for the maximum positive bending moment of the adjacent piles is enhanced by the increasing length of isolation piles. The isolation effects become more outstanding as the lengths of isolation piles increase.