既有暗挖区间扩挖优化技术分析

介绍了北京地铁10号线太阳宫站～三元桥站区间既有矿山法暗挖隧道扩挖为人防段的2种施工方案,在分析了原设计方案9导洞扩挖的优缺点的基础上,提出了"十字撑4导洞"的优化方案,该方案将既有暗挖区间内的十字内撑逐步转换为人防扩挖段初衬的中隔墙与中隔壁,避免了大量的破除工作,将9导洞暗挖施工转换为了4导洞施工,大大缩短了施工工期,降低了工程总体造价.并将原设计人防段由矩形形式变换为马蹄形形式,结构受力更加合理.

Analysis on Excavation Optimization Construction Technology for Existing Underground Cut Running Tunnel

Two kinds of mining construction methods for the civil air defence section by excavating an existing underground cut running tunnel of the interval tunnel from Taiyanggong station to Sanyuan Bridge Station of Beijing Metro Line 10 were described.By analyzing the advantages and disadvantages of the original excavation constructon design with 9 pilot tunnels,the optimization construction method with cross brace and 4 pilot tunnels was established.The optimization method changes the cross brace of the existing underground cut running tunnel to the middle-wall and central diaphragm of the civil air defence,and greatly reduces the construction period and the overall project cost,and changes the rectangular form to a horseshoe-shaped form with the more reasonable force structure.