电渗增强桩模型试验与承载理论研究

MODEL TEST AND BEARING THEORETICAL RESEARCH ON ELECTROOSMOTIC REINFORCED PILE

为研究布桩方式、导电塑料排水板的布设形式对电渗增强桩电渗效果的影响,开展了电渗增强桩模型试验。试验得到了电渗平均排水量、电流、有效电势、桩-土界面电阻、桩周土体沉降、电渗前后桩周土的抗剪强度及电渗增强桩的承载力极限值等数据。数据分析发现:导电塑料排水板正方形排列条件与错位排列条件的电渗试验相比之下,正方形排列条件下的电渗效果更好,但错位排列条件经济效益更好且便于施工,因此仍需结合实际情况选择排列条件;正方形布桩与三角形布桩条件相比,电渗处理后平均排水量更大,桩的承载力和桩周土体抗剪强度也更大,因此正方形布桩条件下的电渗处理效果更好;结合圆孔扩张理论、二维电渗固结理论以及承载时效理论,推导得到电渗增强桩承载力理论;将理论计算值与试验实测值进行对比,发现计算误差在3.1%~5.6%。

In order to study the influence of arrangement of pile and conductive plastic drainage board on electroosmosis effect,the model test of electroosmotic reinforced pile was carried out.The variation of average electroosmosis drainage,current,effective potential,pile-soil interface resistance,settlement of soil around pile,shear strength of soil around pile before and after electroosmosis and bearing capacity of displacement pile were revealed.The analysis shows that electroosmotic effect is better under square arrangement of conductive plastic drainage plate,but the dislocation arrangement condition is more economical and convenient for construction,so the arrangement condition still needs to be selected according to the actual situation.In the condition of square arrangement,the average discharge is higher,and the bearing capacity of piles and the shear strength of soil around piles are also larger,so the effect of electroosmosis treatment under the condition of square piles is better.According to the theory of cavity expansion and two-dimensional electroosmotic consolidation,the theory of ultimate bearing capacity of electroosmotic reinforced pile is derived.Comparing the theoretical calculation value with the test results,it is found that the calculation error is between 3.1%and 5.6%.