深部岩巷U型钢支架屈曲变形失稳分析

Analysis of Buckling Deformation and Instability of U-Steel Support in Deep Rock Roadway

根据朱集西煤矿11煤底板巷围岩工程地质条件和巷道变形破坏特征,结合U型钢多段支护特点,构建了U型钢支护支架—围岩承载力学模型,分析了深部软弱岩层条件下U型钢受力特征。通过支架承载能力的计算与校核,获得该条件下U型钢支架弯矩、剪力、轴力的分布特征,确定了应力集中分布的位置,对U型钢支架屈曲变形进行分析。提出了U型钢支护薄弱环节的加强支护方案,即在棚腿中部、肩窝和拱顶梁中部3个关键部位进行锚杆索配纵向钢带梁的支护方法,提高了支架—围岩的整体承载性能,使返修巷道的支护取得了良好的效果。

According to the engineering geological conditions,as well as the deformation and failure characteristics of the floor roadway of No.11 coal seam in Zhujixi coal mine,combining with the multistage support features of U-steel support,the rock bearing mechanics model for support-surrounding rock of U-steel support has been built,and the force characteristics of U-steel under the condition of deep soft rock were analyzed.Based on the calculation and verification of the capacity of the support,distribution characteristics of bending moment,shear force and axial force were obtained.The location of stress concentration distribution was determined,and the buckling deformation of U-steel support was analyzed.The reinforcement scheme of U-steel support with weak intercalated layers has been put forward,that support method for longitudinal steel girder with anchor cables to the 3 key parts including the middle of the leg,the shoulder hole and middle of arch beam.The overall bearing performance of the surrounding rock was improved,and the support of repaired roadway has achieved good results.