水下浅埋软岩隧道施作拱墙二衬力学效应的现场实测与分析

Field measurement and analysis on mechanical effects of the arch wall secondary lining construction for the shallow,soft rock and underwater tunnel

以一座用矿山法施工的水下浅埋软岩公路隧道为工程背景,基于现场实测数据,分析了施作拱墙二衬对初期支护受力性状的影响以及拱墙二衬本身的受力特性。研究结果表明:与浇注拱墙二衬混凝土的前一天相比,浇注完拱墙二衬混凝土后第20d,初期支护的局部锚杆轴力和局部型钢拱架应力明显减小,说明施作拱墙二衬能分担初期支护承受的部分围岩荷载;而初期支护将承担的部分围岩荷载转移给拱墙二衬后,使拱墙二衬混凝土的应力增加。研究结论可为类似水下隧道的衬砌设计与施工提供参考。

Taking a shallow,soft rock and underwater road tunnel by the mining method as the project background,based on the measured data,the effects of the arch wall secondary lining construction on the mechanics characters of the primary support are studied,and the mechanics characters of the arch wall secondary lining are analyzed.The results show that the arch wall secondary lining can share the partial surrounding rock pressure,which makes local inner force of the anchor and local stress of the section steel frame decrease obviously after 20 days following pouring the arch wall secondary lining concrete;the stress of the arch wall secondary lining concrete increases as the primary support transfers the partial surrounding rock load.The conclusions can be adopted in the design and construction of the lining of the similar underwater tunnel.