沧州市地下水开采与地面沉降地裂缝模拟预测

摘要

To further improve the accuracy of groundwater exploitation-induced ground deformation simula⁃tion, based on the Biot’s consolidation theory and combined with the nonlinear rheological theory of soil, a three-dimensional full coupling mathematic model was set up,in which the constitutive relation in Biot’s consolidation theory was extended to viscoelastic plasticity,the porosity,permeability coefficient and parame⁃ters of soil deformation dynamic relations with the effective stress were considered,and the Galerkin finite element method was taken to solve the model. On that basis,the groundwater seepage field,ground subsid⁃ence and ground fissures development trend was simulated and forecasted in Cangzhou City, Hebei Prov⁃ince. The results show that when the cone of groundwater depression and land subsidence occurred due to over pumping,the horizontal displacement totally directing to cone of groundwater depression of soil will be caused, and the large value of horizontal displacement is concentrated at the edge of cone of groundwater depression,where is the ground fissure high incidence area.%　　为进一步提高地下水开采诱发地面变形模拟的准确性，以比奥固结理论为基础，结合土体非线性流变理论，将比奥固结理论中的本构关系推广到黏弹塑性，并考虑孔隙度、渗透系数、土体的变形参数随有效应力的动态变化关系，建立了地下水开采与地面沉降三维全耦合数学模型，并应用伽辽金有限单元法对模型进行求解，模拟了河北省沧州市地下水开采引起的地下水渗流场、地面沉降、地裂缝发生发展趋势。结果表明：抽水引起地下水位降落漏斗和地面沉降的同时，将导致土体发生总体指向地下水位降落漏斗中心的水平位移，水平位移较大的地区集中分布在地面沉降漏斗的边缘，是地裂缝的高发区。