软岩小净距隧道施工力学效应研究

以软岩小净距隧道在不同开挖方式下达到稳定后围岩和复合衬砌的力学效应为对象,重点分析不同开挖方式下锚杆、喷射混凝土层和二次衬砌的受力特点,考察不同净距对中夹岩柱塑性区的影响.结果表明：施工小净距隧道应慎重选择后继施工隧道的开挖方式;后继隧道施工的开挖方式直接对先行既有隧道锚杆、喷射混凝土层和二次衬砌应力状态产生很大影响;中夹岩柱塑性区大小与净距紧密相关,同时,隧道埋深和围岩类别也是影响塑性区大小的重要因素.

Study on Mechanical Effect of Small-distance Tunnels Located at Soft Ground

Mechanical effect of ground and composite lining is taken as study object after the small-distance tunnels located at soft ground achieves stability by different excavation methods,and the analysis is focused on mechanical characteristics of bolt,shotcrete,secondary lining,also the influence of middle rock wall different interval on the plastic zone of middle rock wall.The result shows that the excavation method of subsequence construction tunnel should be chosen carefully,and the excavation method of subsequence construction tunnel has great influence on stress state of bolt,shotcrete,secondary lining of former tunnel.The size of interval is the most important factor which influences magnitude of the plastic zone,and covering depth and the classification of rock mass are also important factors.