竖向电渗增强桩承载理论及试验验证

Bearing theory and experimental verification of vertical electroosmosis reinforced pile

为将电渗固结理论应用于竖向电渗增强桩承载力研究中,以Esrig一维电渗固结理论为基础,推导得到了考虑有效电势非线性变化的一维电渗固结理论,并将其与承载时效理论结合得到竖向电渗增强桩承载理论。同时开展竖向电渗增强桩模型试验,通过控制变量法,将试验工况分为自下而上电渗组与自上而下电渗组,通过模型试验得到各组有效电势、增强桩承载力、桩周土体抗剪强度等数据。分析得到两组试验的有效电势变化情况基本符合按线性下降再保持不变的规律,将有效电势变化情况拟合运用于所推导的竖向电渗增强桩承载理论中,并计算得到竖向电渗增强桩承载力理论值。通过试验结果与理论值的验证对比发现,自下而上电渗组与自上而下电渗组计算误差分别为17.47%与10.0%,考虑到重力效应在竖向电渗中的影响,因此存在一定的合理计算误差,可验证竖向电渗增强桩承载理论的准确性。

In this work,the traditional electroosmotic consolidation theory is applied to the research of the bearing capacity of vertical electroosmotic reinforced piles.Basing on Esrig’s one-dimensional electroosmotic consolidation theory,the onedimensional electroosmotic consolidation theory considering the nonlinear change of effective potential was deduced,and then combined with the bearing aging theory to derive the bearing theory of vertical electroosmotic reinforced pile.Meanwhile,the model test of vertical electroosmosis reinforced pile was carried out.Using the control variable method,the experimental conditions were divided into two directions of electroosmosis from bottom to top and from top to bottom.Results such as effective potential,enhanced pile bearing capacity and shear strength of soil around the pile were obtained.The analysis shows that the variation of the effective potential of the two groups of tests basically conforms to the law of decreasing linearly and then remaining the same.The change of effective potential in the electroosmosis test was applied to the deduced bearing theory,and the theoretical value of the bearing capacity of vertical electroosmotic reinforced pile was calculated.Comparing the theoretical results with the experimental results,it is found that the calculation errors of the bottom-top electroosmosis group and the top-bottom electroosmosis group are 17.47%and 10.0%,respectively.Considering the influence of gravity effect in vertical electroosmosis,certain calculation errors are reasonable,and also can verify the accuracy of the bearing theory of vertical electroosmosis reinforced piles.