软基底排土场周边地表变形解析分析

Analytical analysis of surface deformation around soft foundation dump

为解决露天矿软基底排土场载荷引起铁路周边土体变形的问题,将排土场简化为作用在地面上的梯形分布载荷,建立半无限弹性平面地基的力学模型,运用平面弹性力学方法和积分叠加原理,推导出二维地表沉陷公式,并分析排土场周边地表变形规律.研究结果表明:当其他参数相同时,地表倾斜和水平变形与距坡脚距离、基底土体弹性模量、泊松比、边坡角度均成反比,与边坡高度成正比.当坡脚距离较小、排弃高度增大时,水平变形显著增加.现场监测数据验证了弹性解析法的准确性,排土场排弃高度和角度与排弃物料量成正比.获得的软基底排土场周边土体变形规律为确保铁路、建筑物和工程设施安全提供理论依据.

In order to solve the problem of the railway surrounding soil deformation caused by the load of the open pit soft substrate dump,the dump is simplified to the trapezoidal distribution load acting on the ground.Mechanical model of semi-infinite elastic plane foundation is setted up.The method of plane elasticity and the two-dimensional surface subsidence formula are calculated by planar elastic mechanics method and integral superposition principle.The surface deformation pattern around the soil dump is analyzed.The results show that when other parameters are the same,the surface inclination and horizontal deformation are inversely proportional to the distance from slope foot,the elastic modulus of foundation soil,Poisson’s ratio,slope angle,and directly proportional to the height of slope.When the slope toe distance is small and the abandon height is increased,the horizontal deformation is significantly increased.The accuracy of the elastic analysis method is verified by the field monitoring data.The height and angle of the waste dump are proportional to the amount of waste material.The theoretical basis for ensuring the safety of railway,buildings and engineering facilities are provided by the obtained deformation law of soil around the soft substrate soil dump.