碎石桩复合地基桩土应力比计算

首先分析了桩土应力比计算方法及其计算中存在的问题.针对这些问题,通过引进圆孔扩张理论,根据平衡条件及位移协调条件,导出了受荷过程中桩土应力应变关系.并针对桩体间距不同,桩间土应力亦不同的实际情况,提出了桩体影响半径概念,分别得到了不同桩间距下的复合地基桩土应力比计算公式.与已有方法相比,该方法能较好地模拟桩体侧向膨胀造成的桩土共同作用现象,并能充分考虑桩体间距的重叠效应.最后,基于相似理论完成了桩土应力比的室内模型试验,获得了相应的实测结果,实测值与计算值最大误差为12%,说明该方法可以满足工程应用的需要.

Calculation for Pile-soil Stress Ratio in Crush Stone Pile Composition

After analyzing the general calculation methods of pile-soil stress ratio and pointing out their defects,this paper derived a new formula to calculate the stress-strain of pile and soil in loading process by using the theory of round-hole expansion and the harmony condition.Then,considering the stress of soil changes by different pile arrangement,a concept of pile influence radius was put forward,and the formula of pile-soil stress ratio to pile composition with different pile arrangement was derived.Compared with the general methods,our method can take into account the mutual action between pile and soil,and the overlapping effect caused by pile arrangement.A laboratory model test based on similarity theory was conducted,and the error was below 12%,which demonstrated that our method could satisfy the engineering requirement.