2015年4月上 施工技术 第44卷第7期 CONSTRUCTION TECHNOLOGY 63 D0I:10.7672/5js2015070063 后注浆超长桩试验及极限承载力研究 张春锋，王笑2，姚文娟1 (1.上海大学土木工程系，上海200072；2.上海长凯岩土工程有限公司，上海200070) [摘要]后注浆技术能弥补常规灌注桩存在的承载缺陷，现广泛适用于高层、超高层建筑.通过现场静载试验，对 比分析非注浆桩和后注浆桩的承载性状，试验表明：注浆可大幅提高单桩承载力；轴力随着深度的增加而减少；桩 端注浆时端阻比最大，但仍只有1%，端阻力不能充分发挥；后注浆侧阻力的提高主要来自桩身中下部，对于超长 桩，无论注浆与否，其桩顶荷载主要由桩侧摩阻力提供.桩端注浆对单桩承载力的大幅提高使得规范承载力确定 方法过于保守，提出的改进方法计算得到的极限承载力和实测值最接近，误差在6.4%左右. [关键词]桩基础；高层建筑；钻孔灌注桩；后注浆；试验；承载力 [中图分类号]TU753.3 [文献标识码]A[文章编号]1002-8498(2015)07-0063-05 Experimental and Theoretical Study on Ultimate Bearing Capacity of Post-grouted Super-long Pile Zhang Chunfeng' Wang Xiao2 Yao Wenjuan' (1.Department of Civil Engineering Shanghai University Shanghai 200072 China; 2.Shanghai Changkai Geotechnical Co.Ld.Shanghai 200070 China) Abstract:Due to the shortings of low bearing capacity bringing by the bored pile post-grouted bored piles have been widely used in tall buildings.Bearing capacity characteristics of grouting pile and non- grouting bored pile are analyzed paratively based on the statie load test in the field.Test results are shown as follows that the bearing capacity of single pile can be significantly strengthened by grouting the axial force decreases with the increase of the soil depth the ratio of pile end resistance to pile top load is the maximum with only 10 percent when the pile end is grouted and the end resistance can't make full contribution the increase of side resistance of post-grouted pile mainly stems from the middle and lower ...
后注浆超长桩试验及极限承载力研究.pdf
