某水库导流洞改建泄洪洞衬砌方案对比

Comparative Study on Reconstruction of Diversion Tunnel Lining

某水库导流洞将改建为泄洪洞,在其"龙抬头"段的侧墙部位,原来衬砌处理有三种方式:拆除原衬砌,重新设计厚2 m的衬砌;把原衬砌当岩体,不考虑其结构效应,设计厚0.75 m的新衬砌;进行新老结合处理,加厚原衬砌。利用ANSYS软件,分别采用Beam3梁单元和Solid65实体单元,对上述不同厚度的衬砌结构进行应力和内力计算,尤其是新老结合面的剪力计算。结果表明:经过处理后的新老混凝土组合衬砌在新混凝土龄期到达28 d之后,能够承受相应的设计荷载。

In a reservoir, one diversion tunnel is planned to be changed into bottem outlet. In the side wall of tunnel spillway section, there are three ways for the treatment of the existing lining. The first one is to redesign a concrete lining with the thickness of 2 m. The second one is to de- sign a new concrete lining with the thickness of 0.75 m regarding the existing lining as the rock, and not taking its structural effects into considera- tion. The third one is to pour new concrete on the surface of existing concrete lining after dealing with the surface. Element Beam-3 and element Solid-65 of ANSYS were used to calculate stress and force of linings with different thickness which were mentioned above, and especially the shear on the adjoining faces. The results show that after the surface treatment, the combination of old and new concrete lining can withstand designed loads when the age of new concrete reaches 28 days. The results can provide a reference for the similar projects.