竖向荷载作用下承台(基础)—桩不同构造形式下的工作性状分析

Analyses on the behavior of piled cap(foundation) with different relation between pile and cap under vertical load

在文献[1]采用的现场试验对桩与承台(基础)之间不同构造方式下的承台(基础)—桩—土相互作用进行的研究基础上,首先采用有限元数值分析模拟承台—单桩—土系统的相互作用,通过参数调整,使其能够模拟文献[1]进行的现场试验并给出较为接近的结果。在此基础上,采用数值仿真试验对多桩情况下桩顶与承台直接接触、复合地基及桩顶预留净空基础在竖向荷载作用下的工作性状进行了对比分析与研究,比较了相同荷载、桩长、桩距、承台厚度等情况下各种构造形式基础的受力特点。同时,通过改变桩长、桩距、预留净空大小等影响因素,进一步研究了桩长、桩距、预留净空对多桩桩顶预留净空基础的桩土荷载分担比例和沉降的影响。

One of the authors of this paper has performed field full scale tests to study the interaction of cap （foundation）-pile-soil system where pile and cap（foundation） is in contact with the pile top or not. Based on that,numerical analysis is at first carried to simulate the field test by adjusting some parameters in order to obtain the calculated results close to that of field tests, then these parameters are applied in the numerical analysis of behavior of foundation （ cap）-group piles-soft system under vertical load. By changing the pile length, the pile spacing, the height of gap between pile top and cap, effects of them on the interaction of ratio of foundation （ cap ） -group piles-soil are investigated. Research shows that piled raft with gap between pile and raft has an advantage of mobilizing the resistance of soil beneath raft and the load sharing between raft and pile is more explicit.