隧道下穿采空区围岩变形规律研究

Study on deformation law of surrounding rock of tunnel passing under goaf

为了研究下穿煤矿采空区条件下隧道围岩变形规律,以太原—焦作高铁控制性工程——皇后岭隧道为工程背景,通过开展数值对比试验,分析采空区与隧道不同距离、不同围岩强度、不同支护强度影响下拱顶位移变化规律。结果表明:随着隧道顶部与采空区距离的逐渐增大,拱顶沉降逐渐减小,即距离越大,采空区对隧道围岩稳定性的影响越小,采空区对隧道的有效影响范围约1.7倍的隧道洞径。随着围岩强度等级的降低,拱顶位移呈现指数式增长,隧道围岩稳定性受围岩强度等级影响显著。隧道拱顶位移随着支护强度的增大,位移不断减小,围岩等级越低,支护强度对隧道变形的有效控制效果越好。

In order to study the deformation law of tunnel surrounding rock under the condition of passing through the goaf of coal mine,taking the control project of Taiyuan Jiaozuo high-speed railway-Huanghouling tunnel as the engineering background,through the numerical contrast test,the variation law of vault displacement under the influence of different distances between the goaf and the tunnel,different surrounding rock strength and different support strength is analyzed.The results show that:With the distance between the top of the tunnel and the goaf gradually increasing,the vault settlement gradually decreases,that is,the greater the distance,the smaller the influence of the goaf on the stability of the tunnel surrounding rock,and the effective influence range of the goaf on the tunnel is about 1.7 times of the tunnel diameter.With the decrease of the strength grade of surrounding rock,the displacement of vault increases exponentially,and the stability of tunnel surrounding rock is significantly affected by the strength grade of surrounding rock.The displacement of tunnel vault decreases with the increase of support strength.The lower the grade of surrounding rock is.