开挖卸荷条件下单桩承载力特性的模型试验研究  

Model tests on bearing capacity of single pile influenced by excavation

作　　者：陈锦剑[1] 吴琼[1] 王建华[1] 夏小和[1] 

机构地区：[1]上海交通大学土木工程系,上海200240

出　　处：《岩土工程学报》2010年第S2期85-88,共4页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50679041)

摘　　要：基坑开挖卸荷会导致开挖段桩侧摩阻力缺失以及坑底桩周土围压减小,削弱桩基承载力。针对桩周土体开挖卸荷条件下的单桩承载力特性进行室内模型试验研究,通过模拟地面试桩和坑底试桩的竖向静载模型试验,分析单桩荷载传递过程,测试单桩极限承载力,研究桩周土体开挖卸荷对桩基承载力的影响。对比开挖卸荷前单桩的承载特性,开挖卸荷后桩顶及桩底沉降量均有增加,桩身轴力以及桩端阻力有所增大,模型单桩极限承载力下降。Deep excavation unloading can decrease the bearing capacity of piles.It may cause the lose of skin friction of bored piles and the soil pressure of pit bottom decreased.Indoor model tests are used to analyze the bearing capacity characters of single pile under the excavation unloading.And analysis of the load transmission process of single pile and measurement of its ultimate bearing capacity are carried out by simulating vertical static load experiments of test pile at ground and pit bottom.The influence of excavation unloading on bearing capacity of piles is studied.Compared with normal condition,the settlement of pile top and pile bottom increase.Meanwhile,the axial force of piles and the tip resistance have enlarged after the excavation unloading.The ultimate bearing capacity of model pile declines.

关 键 词：开挖卸荷 单桩承载力 模型试验 

分 类 号：TU473.1[建筑科学—结构工程]