大结构连跨凿岩硐室稳定性分析及支护模拟研究

针对司家营南区矿块大结构参数连跨凿岩硐室布置特点,建立了以载荷、跨度、拱失为变量的超静定三铰拱力学模型,并对硐室围岩稳定性进行了计算,提出加宽硐室间柱至3 m,减小硐室跨度至6 m,实施锚网喷联合支护,约束间柱横向变形的加固措施。同时,研究得到锚杆长度为2 m,间排距为1 000 mm×1 000 mm,采用直径为6.5mm的钢筋,网距300 mm×300 mm,喷射混凝土厚度150 mm的锚网喷支护参数。最后,利用FLAC~(3D)对联合支护进行数值模拟,结果表明优化后的硐室结构尺寸经过锚网喷联合支护能够满足承载要求,限制顶板沉降约72.7%。

Supporting Simulation and Stability Analysis of Large Structure Multi-span Drilling Cavern

Aiming at the layout characteristics of Sijiaying southern large structure multi-span drilling cavern,the three hinged arch mechanical model which variate including load,span and arch loss is established to analyze stability of surrounding rock,and the reinforcement measure that widened between column heading to 3 m,reduce the cavern span to 6 m and imple-mented combined support for confining lateral deformation of studding are proposed. Besides that, the supporting parameters that including bolt length 2 m,inter-row spacion 1000 mm×1000 mm,steel bar from the net 300 mm×300 mm,and shotcrete thickness of 150 mm are obtained. Based on the above analysis results,the combined supporting is simulated based on FLAC3D software,the simulation results showe that the optimized structure of the cavern size after combined support can satisfy the bear-ing requirements,which can limit the roof subsidence of about 72. 7%.