摘要
在采空区对应地表兴建建筑物,地基附加应力的作用可能引起采空区已稳定结构的活化并产生地表残余移动变形,影响建筑物的安全使用;针对薄表土层地区的地基附加应力、荷载影响深度计算模型较少且不完善的特点,需从计算过程简单、参数较少且易获得等角度出发,进一步探索双层弹性介质地基附加应力传递模型。首先将薄表土层地区的地基简化为上部厚度较薄、力学强度较弱的表土层,下部为厚度较大、力学强度较大的岩石层地基模型;其次基于Boussinesp弹性解,假定双层地基的各分层分别为横观各向同性弹性体且地基附加应力传播过程中无动能的变化;再次基于岩土层分界面表土与基岩微单元层的弹性应变能守恒和竖向附加应力平衡条件,建立平衡方程,并借助Matlab对方程中的各分项式进行积分求解与化简,推导出适用于薄表土层地区矩形与圆形均布荷载作用下的基础中心点正下方地基附加应力求解方程;然后根据建筑物地基附加应力影响下的采空区稳定性分析方法,基于C#语言编写出薄表土层地区拟建工程对采空区场地稳定性影响分析软件,实现了地基附加应力计算与采空区稳定性评价的科学与高效化,同时对双层介质地基附加应力求解模型进行了验证并与广泛应用的均一介质模型计算结果进行了对比;最后对双层介质参数E1、μ1与E2、μ2对地基附加应力及影响深度规律进行了分析。结果表明:薄表土层地区双层介质地基附加应力传递模型求解简单、结果科学准确;薄表土层双层弹性地基内竖向附加应力在表土层中传播过程中存在一定程度衰减;相对于均一介质体,双层介质地基附加应力影响深度减少5.3%~10.3%;基岩与表土层的弹性模量E_(2)/E_(1)越大,基岩内部沿深度方向的地基附加应力衰减越明显、传递深度越小;地基附加应力对于表土与基岩的泊�
When constructing some buildings on the surface of mine goaf,the additional foundation stress may cause the activation of the stable structure in goaf,and in turn the residual movement and deformation of surface may affect the safety of buildings.In view of the few and imperfect models for calculating the additional stress and the depth of load ef-fect on thin topsoil layer area,it is necessary to further investigate the additional stress transfer model of double layer elastic medium foundation from the perspective of simple calculation process,fewer parameters and easy access.Firstly,the foundation of thin topsoil area is regarded as the upper layer with thin thickness and weak mechanical strength,and the lower layer is the rock layer with larger thickness and high mechanical strength.Secondly,based on the Boussinesp elast-ic solution,it is assumed that each layer of the double-layered foundation is a transversely isotropic elastomer and there is no change of kinetic energy during the propagation of additional stress in the foundation.Thirdly,based on the conserva-tion of elastic strain energy and the balance condition of vertical additional stress between the micro cell topsoil layer and bedrock layer on the interface of rock and soil layer,the balance equation is established,and each component of the bal-ance equation is solved and simplified in its integral domain with help of Matlab.The equation for solving the additional stress under the center point of foundation with rectangular uniform load and circular uniform load in thin surface soil lay-er is derived.Then,according to the stability analysis method of goaf under the influence of additional stress of building foundation,an analysis software of the influence of proposed construction project on the stability of goaf is written using the C#language,which realizes the scientific and efficient calculation of the additional stress of foundation and the stabil-ity evaluation of goaf.The model for solving additional stress of double layer medium foundation is
作者
高超
田国灿
徐乃忠
张玉军
GAO Chao;TIAN Guocan;XU Naizhong;ZHANG Yujun(Coal Mining&Designing Department,Tiandi Science&Technology Co.,Ltd.,Beijing 100013;CCTEG Coal Mining Research Institute,Beijing 100013,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2024年第11期4365-4376,共12页
Journal of China Coal Society
基金
国家自然科学基金资助项目(52174079)
中煤科工开采研究院有限公司科技创新基金资助项目(KCYJY−2023−MS−02,KCYJY−2024−MS−04)。
