基于圆孔扩张理论顶部加箍碎石桩承载力计算  

Calculation of Bearing Capacity of Geosynthetic-encased Gravel Pile Based on Cavity Expansion Theory

作　　者：陈昌富[1] 李其泽[1] 

机构地区：[1]湖南大学岩土工程研究所,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2011年第10期7-12,共6页Journal of Hunan University:Natural Sciences

基　　金：国家863计划资助项目(2006AA11Z104);湖南省自然科学基金资助项目(03JJY3087)

摘　　要：在碎石桩顶部设置土工合成材料或预制混凝土套筒,可有效改善其承载特性.为研究加箍段对碎石桩承载力的影响,采用Mohr-Coulomb屈服准则,将考虑土体自重效应影响的圆孔扩张理论引入到加箍碎石桩复合地基的承载力计算中,分析了塑性区半径随深度发生变化的规律,得到了复合地基承载力计算公式.在此基础上,进一步研究了扩张重叠作用产生的影响,建立了群桩计算模型,推导出群桩作用下加箍碎石桩的承载力计算公式.工程实例验证表明,采用本文公式的计算结果与现场载荷实验实测结果吻合良好,说明本文公式具有一定的实用价值.In order to improve the bearing capacity, geotechnieal engineers often take geosynthetic-encased measures at the top of the gravel pile. In order to analyze the influence on the ultimate bearing capacity of geosynthetic-encased gravel pile based on the column cavity expansion theorem conside the influence of the soil gravidity stress, the radius of the plastic zone and the bearing capacity calculation method were deduced when Mohr-Coulomb yield criterion was adopted. A new calculation formula based on the model, which considered the expansion overlapped between pile groups, was established. In order to validate the proposed method, a case history was illustrated. The result has indicated that these formulas are practical.

关 键 词：加箍碎石桩 复合地基 承载力 圆孔扩张理论 扩张重叠 

分 类 号：TU472.35[建筑科学—结构工程]