刚性桩复合地基应力场分布的试验研究

刚性桩复合地基沉陷计算问题目前尚未得到较好的解决，主要原因之一：是不甚了解复合地基中应力场的分布规律。为此，在两种土质中各进行了1组9桩复合地基试验。在桩间土及桩身分别埋设压力盒和钢筋计，对刚性桩复合地基桩间土不同深度的竖向应力、桩身轴力、侧摩阻力进行了仔细地观测。所得结果揭示了桩间土竖向应力σ2、桩侧阻的分布规律以及荷载传递的全过程。试验结果可以为复合地基沉降计算的假定提供合理依据，同时，能够为荷载传递机理的研究带来帮助。

Experimental study on stress distribution of composite foundation with rigid piles

In order to investigate the working mechanism of composite foundation with rigid piles, two tests of composite foundation with 9 piles were conducted. In these tests, pressure cells were embedded in the soil to measure the vertical stresses at different depths, whereas stress gauges with vibrating strings were installed in the piles to measure their axial forces, which can be further used to estimate the pile shaft friction. The load was applied step by step and the stresses in the soil and axial forces in the piles were measured for each load step. The test results show the entire process of load transmission; and they can provide useful information for the designer in understanding the bearing characteristics of this type of composite foundation.