地下水位波动下基坑周围地基土的孔压响应半解析解

发布时间：2018-03-30 01:27

本文选题：地下水位波动　切入点：基坑　出处：《岩土工程学报》2014年06期

【摘要】：水位波动条件下的基坑性状研究是随工程实践产生的新课题,而基坑周围的孔压响应机制是该课题的关键问题。将基坑渗流场分区,假设土体总应力不变,将固结方程解耦,利用Laplace、Fourier变换推导了浅层含水层内地下水位波动时板式支护基坑周围地基土孔压响应的二维近似半解析解。利用该解答,对综合系数θ(与土体固结系数、海床厚度、水位波动周期相关)、孔隙流体压缩系数与围护墙插入深度的影响进行分析。结果表明:孔压波动幅值沿基坑最短渗流路径不断衰减,滞后相位不断增大;θ越大,基坑周围地基土的相对孔压波动幅值越小,滞后相位越大,稳态渗流时的相对孔压为地下水位波动条件下不同θ值相对孔压波动幅值的极大值;孔隙流体压缩系数越大,基坑周围的波动孔压响应幅值越小,滞后相位越大;围护墙插入深度越大,主动侧相对超孔压波动幅值越大,被动侧波动幅值则越小。
[Abstract]:The study of foundation pit behavior under the condition of water level fluctuation is a new subject arising from engineering practice, and the response mechanism of pore pressure around the foundation pit is the key problem. The consolidation equation is decoupled if the seepage field of the foundation pit is partitioned, assuming that the total stress of the soil is unchanged, and the consolidation equation is decoupled. By means of Laplace Fourier transform, a two-dimensional approximate semi-analytical solution for the pore pressure response of the foundation soil around the foundation pit of plate supporting foundation pit under the fluctuation of groundwater level in shallow aquifer is derived. By using this solution, the comprehensive coefficient 胃 (and soil consolidation coefficient, sea bed thickness) is obtained. The influence of pore fluid compression coefficient and the insertion depth of retaining wall is analyzed. The results show that the amplitude of pore pressure fluctuation continuously attenuates along the shortest seepage path of foundation pit, and the lag phase increases continuously. The smaller the fluctuation amplitude of relative pore pressure is and the larger the lag phase is, the greater the relative pore pressure of steady seepage is the maximum of the fluctuation amplitude of relative pore pressure of different 胃 values under the condition of groundwater level fluctuation, the greater the compressibility coefficient of pore fluid is. The smaller the response amplitude of wave pore pressure around foundation pit is, the greater the lag phase is, and the greater the insertion depth of retaining wall is, the larger the fluctuation amplitude of active side relative to super-pore pressure is, and the smaller the amplitude of passive side fluctuation is.
【作者单位】：浙江大学滨海和城市岩土工程研究中心;浙江大学软弱土与环境土工教育部重点实验室;
【基金】：国家自然科学基金重点项目(51338009);国家自然科学基金项目(51278462)
【分类号】：TU46

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