考虑地下水位影响的砂井地基强度增长计算  

INCREMENT CALCULATION OF SOIL SHEAR STRENGTH FOR SAND DRAIN FOUNDATIONS CONSIDERING GROUNDWATER LEVEL

作　　者：鲍树峰[1,2,3] 莫海鸿[1] 董志良[2,3] 陈平山[2,3] 

机构地区：[1]华南理工大学土木与交通学院,广东广州510641 [2]中交四航工程研究院有限公司,广东广州510230 [3]中交交通基础工程环保与安全重点实验室,广东广州510230

出　　处：《岩石力学与工程学报》2014年第6期1269-1277,共9页Chinese Journal of Rock Mechanics and Engineering

摘　　要：为深入了解真空联合堆载预压条件下深厚吹填软土地基强度增长的实际规律,基于有效应力原理和应力路径法对地基的强度增长机制进行定性分析,分析结果表明:地下水位线以上土体的强度增长规律和地下水位线以下的土体的强度增长规律是不尽相同的。鉴于此,考虑地下水位的影响,基于有效应力唯一性理论推导出砂井地基强度增长解析解。最后,以珠海港高栏港区某软基处理工程为依托,基于该解析解对真空联合堆载预压恒载过程中土体超静孔压消散稳定后的地基强度增长情况进行计算,并分别与室内无侧限抗压强度试验结果和三轴压缩试验结果进行对比分析,分析结果表明:按不排水剪强度考虑时,不同深度土体强度增长量的计算值与实测值之间的平均误差为8.0%;而按破坏面上的强度考虑时,不同深度土体强度增长量的计算值与实测值之间的平均误差为3.2%。因此,该解析解的计算值与实测结果较为吻合。The actual development of shear strengths of soft soils in the thick hydraulic reclaimed foundations improved by the technology of pumped vacuuming combined with heaped preloading was qualitatively analyzed in terms of the principle of effective stresses and the method of stress paths. The development of soil shear strength under the groundwater level was found to be different from that of above the groundwater level. An analytical solution for soil shear strengths considering the effect of groundwater levels was therefore derived based on the theory of the uniqueness of effective stresses. The increments of soil shear strength at different depths after the dissipation of the excess pore water pressure under constant load in an area at Gaolan, Zhuhai seaport were calculated with the derived analytical solution. Comparisons with the results from the unconfined compression test and triaxial compression test revealed that the averaged error between the calculated and measured values is only 8.0% in terms of the undrained shear strength and is only 3.2% in terms of the shear strength in soil failure surface Therefore, the calculated results based on the analytical solution agree well with the measured results.

关 键 词：地基基础 砂井地基 地下水位 有效应力原理 应力路径法 有效应力唯一性理论 强度增长解析解 

分 类 号：TU47[建筑科学—结构工程]