逐级加荷下考虑施工扰动的复合地基固结解

ANALYTICAL SOLUTION FOR THE CONSOLIDATION OF A COMPOSITE FOUNDATION CONSIDERING THE CONSTRUCTION DISTURBANCE UNDER PROGRESSIVE LOADING

在线性加载的情况下,考虑了扰动区土体水平渗透系数抛物线变化以及桩周土体的径、竖向组合渗流,给出了该问题的控制方程以及解答。在超静孔压解的基础上,给出了复合地基的固结度的表达式。最后对复合地基的固结性状进行了分析并与以往解做了比较,结果表明:加荷历时越久,地基固结越慢;桩体施工对周边土体的扰动越大,地基固结越慢;所给出的地基固结度较考虑扰动区土体水平渗透系数直线变化或者保持不变的解给出的固结度要快。

Under the condition of progressive loading, considering a parabolic variation of the horizontal permeability of soil in the disturbed zone and the combination seepage along both radial direction and vertical direction in the surrounding soil, the governing equations for the consolidation of a composite foundation was derived and their solutions were obtained. On the basis of the solutions for the excess pore water pressures, the average degree of consolidation for the composite foundation was obtained. Then the consolidation behaviors of the composite foundation were analyzed and a comparison between the present solution and some previous solutions was made. The results show： the longer the loading period, the slower the rate of consolidation; the greater the disturbance effect, the slower the rate of consolidation; the rate of consolidation calculated by the present solution is more rapid than that by the previous solutions which assumed the horizontal permeability of soil in the disturbed zone was linearly changed or kept constant as a reduced value.