弹塑性变形条件下抽水引起的地面沉降三维数值模拟

发布时间：2018-04-18 15:06

本文选题：TOUGH-FLACD + 地面沉降　；参考：《水文地质工程地质》2017年02期

【摘要】：基于部分耦合原理,采用TOUGH2和FLAC~(3D)建立抽水引起的三维地面沉降弹塑性模型,模型中综合考虑土体的弹塑性变形特征、渗流-应力的双向耦合作用以及参数的非线性,探讨了持续抽水和脉冲抽水两种抽水过程中地面沉降发展演化过程。研究结果表明:(1)集中抽水停止后地面沉降会发生回弹,抽水中心沉降量不断减小。由于水平方向存在水力梯度,地下水继续向地下水位漏斗中心渗流从而导致沉降漏斗的范围仍继续扩大;(2)脉冲抽水导致土体的孔隙水压力、渗透系数以及沉降量均呈周期性波动变化,地面沉降会局部回弹,但总体仍随着抽水的持续,沉降量不断增加;(3)在抽水量相同前提下,对比持续抽水与脉冲抽水两种方式引发的塑形沉降量可知,抽水速率小、脉冲式多次开采导致的塑性沉降量较小,持续抽水的抽水速率越小、脉冲抽水间隔越短越有利于控制地面沉降。研究成果为地面沉降数值模拟提供了一种新方法,其中算例研究能为抽水条件下地面沉降的控制提供参考。
[Abstract]:Based on the principle of partial coupling, a three-dimensional elastic-plastic model of land subsidence induced by pumping is established by using TOUGH2 and FLAC3D. The elastoplastic deformation characteristics of soil, the two-way coupling of seepage and stress and the nonlinearity of parameters are considered in the model.The evolution process of land subsidence in the process of continuous pumping and pulsed pumping is discussed.The results show that when the concentrated pumping stops, the land subsidence will rebound and the subsidence of the pumping center will decrease.Due to the existence of hydraulic gradient in the horizontal direction, the groundwater continues to flow to the center of the funnel of the groundwater table, thus causing the settlement funnel to continue to expand the scope of the subsidence funnel.) the pulse pumping results in the pore water pressure of the soil.The coefficient of permeability and the amount of settlement fluctuate periodically, and the land subsidence bounces back locally, but as a whole, with the continuous pumping, the settlement increases continuously) under the condition of the same pumping capacity,Compared with the plastic settlement caused by continuous pumping and pulse pumping, it can be seen that the pumping rate is small, the plastic settlement caused by pulse multiple mining is smaller, and the pumping rate of continuous pumping is smaller.The shorter the pulse pumping interval, the better the control of land subsidence.The research results provide a new method for numerical simulation of land subsidence, and the numerical examples can provide a reference for the control of land subsidence under pumping conditions.
【作者单位】：南京大学地球科学与工程学院;
【基金】：国家自然科学基金项目(U1503282,41672229,41172206)
【分类号】：P642.26

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