旋挖扩底抗拔桩受力机理及扩底段作用机制研究
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(1 上海市城市建设设计研究总院， 上海 200125； 2 上海岩土工程勘察设计研究院有限公司， 上海 200031)
［摘要］依托中国2010年上海世界博览会B片区地下空间工程，进行11组旋挖扩底抗拔桩静载荷试验，并测试桩身轴力。选取持力层分别为黏性土和砂土的1#试桩和11#试桩来探讨扩底抗拔桩的受力机理。试验得出，最大加载量下扩底抗拔桩桩身变形量占桩顶变形比例可达80%，并采用数值分析拟合试桩曲线，分析不同持力层的扩底段受力特点，发现扩底抗拔长桩对桩周土体应力的影响范围为径向1倍扩底段长度、纵向沿桩端向上2倍扩底段长度。［关键词］抗拔桩; 旋挖扩底; 受力机理; 持力层中图分类号：TU473 文献标识码：A 文章编号：1002-848X(2016)08-0065-05
Study on stress mechanism of enlarged-base uplift pile and enlarged-base interaction mechanismXu Zhuangtao1, Zhang Jing2(1 Shanghai Urban Construction Design & Research Institute, Shanghai 200125, China; 2 Shanghai Geotechnical Investigations & Design Institute, Shanghai 200031, China)Abstract: Based on underground space project of the World Exposition Shanghai China 2010 B area, 11 groups of static load tests of enlarged-base uplift piles were carried out and the pile axial forces were measured. Stress mechanism of enlarged-base uplift pile was discussed based on 1# pile and 11# pile with bearing stratums of silty clay and silt respectively. Test results show that deformation of the pile under maximum test loading can be 80% of pile top deformation. Then numerical analysis was taken to fit stress features of enlarged-base pile. Mechanical characteristics of enlarged-base in different bearing stratums were analyzed and it is found that influence range of enlarged-base uplift pile on soil stress around enlarged-base is length of enlarged-base on radial direction and twice the length of enlarged-base from pile tip on longitudinal direction.Keywords: uplift pile; enlarged-base; stress mechanism; bearing stratum
作者简介：徐壮涛，硕士，高级工程师，一级注册结构工程师，Email：xztxzt@yeah.net。
