高应力、低强度是引起软岩巷道产生塑性大变形的主要原因之一.通过分析某矿皮带下山变形破坏特征及围岩力学状态,总结了其变形失稳原因;基于耦合支护理论,在原支护方案的基础上,提出了全断面高强锚杆+长锚索+控底混凝土层耦合支护(方案1)和长短多级锚索+高强锚杆+柔性让压充填层+U型钢联合支护(方案2)2种优化方案,采用FLAC3D模拟了2种优化方案的支护效果,确定方案2作为最佳支护方案;工业性试验表明,采用该方案后,巷道顶板最大下沉量、底鼓量及两帮最大移近量分别为37.8 mm、97.8 mm和105.3 mm,基本控制了围岩有害变形.%High stress and low strength of surrounding rock is one of the main causes leading to large plastic deformation of soft rock roadway.The deformation instability mechanism is summarized by analyzing the deformation failure characteristics of the belt transportation lane in a mine and the mechanical state of surrounding rocks.Based on the coupling support theory, two optimized support schemes are proposed,that are the full-section high strength bolt + long anchor cable + control bottom concrete layer coupling support (scheme 1) and the multistage anchor cable + high strength bolt + flexible release pressure pack + U-shaped steel joint support(scheme 2).Then,the support effect of two optimized schemes is simulated by FLAC3D, and the scheme 2 is determined as the optimal support scheme.The industrial test shows that the maximum subsidence,floor heave and two-side moving amount of roadway roof are respectively 37.8mm,97.8mm and 105.3mm after adopting the scheme 2.It can basically control the harmful deformation of surrounding rock.
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