半明半暗连拱隧道合理施工方法研究

STUDY ON CONSTRUCTION METHOD OF DOUBLE-ARCH TUNNEL WITH HALF-OPEN AND HALF-HIDDEN STRUCTURE

连拱隧道半明半暗结构形式是隧道洞口地表偏斜地段的一种优选方案,针对该种结构形式进行合理施工方法的研究较少。结合一具体工程实例,提出半明半暗连拱隧道的3种不同施工方法,从理论探讨、力学计算、施工衔接、工期及环境影响等多方面对3种施工方法进行比较,得出连拱隧道半明半暗段采用先暗洞后明洞的施工方法更有利于隧道围岩及支护结构的长期稳定,同时在施工便利性和工期等方面也具有一定的优势,所得结论对其他同类工程具有一定的指导意义。

When the ground surface at the entrance of tunnel is sloping,the structure of double-arch tunnel with half-open and half-hidden structure is an optimum pattern to be selected.But the rational construction method of this structure hasn′t studied much.Based on a typical tunnel case,three construction methods of the double-arch tunnel with half-open and half-hidden structure are put forward.Then,from the aspects of theory analysis,mechanical calculation,construction convenience,time limit,and environment influence,etc,the advantage and disadvantage of these three methods are compared.A conclusion is drawn that,for the double-arch tunnel with half-open and half-hidden structure,the construction method with the hidden tunnel excavated first and the open tunnel excavated second is better than the other two construction methods,because this method is beneficial to the steady of surrounding rock and lining of tunnel,and also has some advantageous to construction convenience and time.The conclusion will be a guide to the other similar engineering.