碎石桩复合地基承载力性状分析

按等置换率原则建立碎石桩复合地基有限元计算模型，在考虑基础刚度、荷载强度变化条件下对比分析了天然地基与复合地基附加应力分布特征、塑性区扩展规律；根据有限元计算结果分析了桩身荷载传递规律并与实测结果对比确定桩身应力随桩身呈指数衰减。计算结果还表明：桩土应力比不仅与桩土模量比有关，也与荷载水平及置换率有关；在鼓胀破坏情形下桩体侧向变形性质取决于桩周土而与置换率、模量比、桩长无关。

THE ANALYSIS OF CHRACTERISTICS OF THE STONE COLUMN COMPOSITE FUNDATION ABOUT ITS BEARING CAPACITY

Based on even replacement rate principle,this paper set up model of finite element for calculating about the stone column composite fundation,and after consider the variety of rigidity of fundation?load strength,we contrast and analyse the distributing characters of additional stress and expand disciplinarian of plastic zone about natively fundation and composite fundation ;based on the result of finite element,this paper analyse the disciplinarian of transmission of load on pile shaft and make sure stress on pile shaft assuming exponential decay along with pile shaft from result of actual measurement.Result make clear also that the stress ratio between pile and soil is not only bear on module ratio between pile and soil,but also bear on class of load and replacement rate;and on the condition that the pile is destroied by bilge ,the character of lateral deformation of pile shaft lie on the soil around pile,not lie on the replacement rate?module ratio and pile length.