土工袋装砂桩复合地基室内模型静载试验  

Model test of foundation with geosynthetic-encased stone column

作　　者：段园煜[1,2] 张仪萍[2] 郭书魁[2] 蒋承杰[3] 

机构地区：[1]浙江省交通规划设计研究院,浙江杭州310006 [2]浙江大学建筑工程学院,浙江杭州310058 [3]浙江建设职业技术学院城市建设工程系,浙江杭州311231

出　　处：《江苏大学学报（自然科学版）》2013年第5期599-604,共6页Journal of Jiangsu University：Natural Science Edition

基　　金：中央高校基本科研费资助项目(2011FZA4021);浙江省重点科技创新团队计划项目(2010R50037);浙江省教育厅科研计划项目(Y201018981)

摘　　要：为了研究袋装桩型复合地基的受力变形特性,对袋装砂桩和传统砂桩处理的软土复合地基进行了分级静力加载室内模型试验.分析了各级试验荷载下的沉降、桩土应力比以及袋体张力分布等变化规律.试验结果表明:袋装砂桩的性能明显优于传统砂桩的性能.将试验结果与现有的弹性理论和弹塑性理论分析结果进行对比.通过相互间的沉降和桩土应力比的比较,发现弹性理论过高地估计了复合地基的性能,而弹塑性理论与试验结果更为接近;弹塑性理论所提供的袋体张力与试验结果也比较相近.弹塑性理论适合评估袋装桩型复合地基的主要受力变形性能,可用于实际工程的设计计算.To investigate the stress-strain characteristics of foundations with geosynthetic-encased stone columns, static stair-cased loading tests were conducted on the unit cell model of composite foundations with geosynthetic-encased stone column （GEC） and ordinary granular column （OGC）. The settlements, stresses of column and soil at the top of model and the stresses of geotextiles under different loadings were analyzed. The results demonstrate that under the same loading, the model with GEC has less settlements and bigger column-soil stress ratio than those with OGC. Comparing the test results of settlements and stresses ratio of column and soil with elastic and elastoplastic theoretical analyses, it is found that elastic analysis overestimates the performance of composite foundation with OGC or GEC is overestimated by e- lastic analysis, while the elastoplastic theoretical analysis shows good agreement with experimental data. The elastoplastic theoretical analysis presents closer encasement stress to the test results. The elastoplastic theoretical analysis is suitable for engineering design of foundations with geosynthetic-encased stone columns.

关 键 词：复合地基 袋装砂桩 单元体模型 静载试验 变形 

分 类 号：TU443[建筑科学—岩土工程]