逐级加荷下混凝土芯砂石桩复合地基固结解析解研究  

Analytical Solution for Consolidation of Concrete-cored Sand-gravel Pile Composite Foundation under Step Loading

作　　者：吴辛[1] 杨燕伟[2,3] 武颖利[3] 

机构地区：[1]中交第二公路工程局有限公司,西安710065 [2]中铁四院集团西南勘察设计有限公司,昆明650200 [3]南京水利科学研究院,南京210029

出　　处：《路基工程》2015年第5期66-70,80,共6页Subgrade Engineering

基　　金：国家自然科学基金(51208321);水利部公益性行业科研专项经费项目(201201015);江苏省科技支撑计划项目(BE201130305)

摘　　要：在线性加载的情况下,考虑了混凝土芯砂石桩复合地基中砂石桩的环形排水通道、土体施工扰动和地基附加应力分布形式,并采用桩土共同分担荷载的初始条件,得到了复合地基固结问题的控制方程及解答;在此基础上给出了复合地基按变形和应力定义的总平均固结度。最后,分析了加载历时、附加应力分布形式、芯桩与砂石桩直径比对地基固结性状的影响。结果表明:对于混凝土芯砂石桩复合地基按应力定义的固结度与按变形定义的固结度表达式不同;加荷历时越久,地基固结速率越慢;地基固结速率随着地基顶面和底面处的附加应力之比的增大而增大;地基固结随芯桩直径增大而先增大后减慢。For concrete-cored sand-gravel pile composite foundation, circular drainage channel of the piles, soil disturbance during construction and the distribution form of additional stress in the foundation were taken into consideration and, with the loads borne by the soil and piles as the initial condition, the control equation and the analytical solution for consolidation of the composite foundation were obtained; on this basis, the overall average consolidation degree thereof defined in terms of stress and deformation was given. Finally, how the loading duration, the distribution form of additional stress, and the diameter ratio of concrete-cored pile and sand-gravel pile affect the consolidation behavior of the foundation was analyzed. The results show that, for concrete-cored sand-gravel pile composite foundation, the consolidation degree defined in terms of stress has different expression from that in terms of deformation; the longer the loading duration, the slower the consolidation rate; the consolidation rate increases with the ratio of additional stress at the foundation top to that at the bottom; and as the concrete-cored pile＇s diameter increases, the consolidation speeds up first and then slow down.

关 键 词：混凝土芯砂石桩复合地基 固结 环形排水通道 线性加载 施工扰动 

分 类 号：TU473.1[建筑科学—结构工程]