喷筑隐式异型中墙复合式连拱隧道的设计分析

Design and Analysis of a Double-Arch Tunnel with Concealed, Sprayed Irregular-Composite Mid-Wall

为解决连拱隧道防排水效果差、结构耐久性差和施工效率低的问题,文章分析了连拱隧道设计和施工现状,总结了现行结构型式存在的问题,提出了一种新型连拱隧道结构型式。该结构采用一次喷筑钢纤维混凝土的异型隐式中墙,可保证较高的施工效率;中墙在底部采用扩大基础,并在施工时预留岩柱对中墙进行保护,具有较高的施工安全性;采用独立防排水体系和等厚二次衬砌结构,具有较好的防排水效果和耐久性。通过有限元软件三维分析,结果表明:在多种施工步序情况下,该结构型式均能保持施工安全,且实现连拱隧道的快捷施工。

To improve the effects of waterproofing, drainage, structure durability, and construction efficiency of double-arch tunnels, this paper analyzes the state of the art indesign and construction methods for double-arch tunnels, addresses associated problems, and puts forward a new structural type which can effectively guarantee efficient construction by using a concealed irregular middle-wall installed using one-pass sprayed steel fiber concrete. Additionally, construction safety can be guaranteed by the enlarged foundation and protection from the reserved rock pillar. Installing an independent waterproofing and drainage system and a secondary lining with equal thickness results in better performance regarding waterproofing and drainage as well as structure durability. In this paper, a 3D finite element model is created. The results show that this type of structure can ensure safe and rapid double-arch tunnel construction for various working procedures.