复合地基中桩土应力比的试验研究

在实验室条件下，用碎石或灰土圆柱芯增强体与粘性土组成的复合地基单位桩模型，通过复合试样的三轴试验模拟现场碎石桩和灰土桩的工作状态，探讨桩与土的相互作用问题。大量的试验结果表明：复合体的竖向强度不能将两种材料按一定几何比例简单叠加。试验揭示了桩土应力比变化规律及其机理。复合试样在荷载及应变不大时，桩土应力比增加很快，随后荷载逐渐向桩周土集中，桩土应力比减少，这种规律与现场测试的桩土应力比是一致的。

TESTING STUDY ON STRESS RATIO BETWEEN PILE AND SOIL IN COMPOSITE FOUNDATION

A series of triaxial compression tests were conducted on composite-reinforced soil samples made of clay with the varied length gravel or lime-soil pile at the center for simulating the site soil-pile interaction.The experiment illustrates composite sample strength can not be gotten by adding that of reinforcing pile and soil together simply according to their replacement proportion.It also illustrates the principle for stress ratio of reinforcing column to soil,stress ratio of reinforcing column to soil increases and reaches peak rapidly while load and strain is small,then decreases.This law is the same as that of the field measurement.