考虑砂石桩固结的混凝土芯砂石桩复合地基固结解析解  

Analytical solution for consolidation of composite foundation with concrete-cored sand-gravel piles

作　　者：石北啸[1,2] 杨燕伟[2] 谢荣星[2] 吴辛[3] 

机构地区：[1]河北工程大学资源学院,河北邯郸056038 [2]南京水利科学研究院岩土工程研究所,南京210029 [3]中交第二公路工程局有限公司,西安710065

出　　处：《岩土力学》2013年第10期2835-2840,2856,共7页Rock and Soil Mechanics

基　　金：河北省自然科学基金项目(No.E2012402049);国家自然科学基金项目(No.51208321)

摘　　要：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、砂石桩体内的径、竖向渗流和土体施工扰动,并采用桩土共同分担荷载的初始条件,得到了混凝土芯砂石桩复合地基固结问题的控制方程,给出了控制方程的解答;并分别给出了复合地基按应力和按变形定义的总平均固结度,分析了砂石桩桩体渗透系数、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;地基的固结随着砂石桩桩体渗透系数增加而加快;砂石桩直径一定的情况下,固结速率随芯桩直径增大先增大后减小。最后对本文解和以往的两种解做了比较,与以往解相比本文解能够同时考虑环形通道和桩土荷载分担,给出的固结度介于以往的两种解之间。Considering the annular drainage section of concrete-cored sand-gravel pile composite foundation, both radial and vertical flows within the sand-gravel pile and soil construction disturbance, using the initial condition of load beared by soil and pile, the governing equations of consolidation problem of composite foundation with concrete-cored sand-gravel piles are derived; the analytical solution to the governing equations is obtained; the overall average degree of consolidation defined in terms of stress and deformation is given; and the influences of several factors, such as the permeability coefficient of sand-gravel piles, diameter ratio of concrete-cored pile and sand-gravel pile on the consolidation of composite foundation are analyzed. The results show that the solution of overall average degree of consolidation in terms of stress is not equal to that in terms of deformation; the greater the permeability coefficient of sand-gravel piles is, the faster the consolidation rate is; under the condition of a certain diameter size of sand-gravel piles, with diameter of concrete-cored pile increasing, the consolidation rate is increased at first and then decreased. Finally, a comparison between the present solution and two previous solutions is made. Compared with two previous solutions,the present solution considers the influences of annular drainage section and load beared by soil and pile together, the overall average degree of consolidation calculated by the present solution is between two previous solutions.

关 键 词：混凝土芯砂石桩复合地基 径向渗流 固结 环形排水通道 

分 类 号：TU47[建筑科学—结构工程]