浅埋大跨径隧道施工技术

根据仰口隧道浅埋区的复杂地质条件，采用了较为安全的双侧壁导坑法开挖，这种施工方法有其自身的诸多优点，在开挖时，它的断面是分为多个工作面施作，每一个开挖工作面在初支作用下立即形成应力闭合状态．充分利用围岩的自承能力，很好控制了整个施工过程中的应力变形量，为施工创造了良好的经济和社会效益。

Construction Technology of Shallow Buried Large-span Tunnel

According to the complex geological conditions of the upward tunnel in the shallow buried area, a more secure method of double side-wall heading excavation method is used. This construction method has its own advantages. At the beginning of excavation, its section is divided into several working faces. Each face immediately forms closed stress state under the action of the initial support in order to make full use of the self-bearing capacity of rock and totally control the amount of stress deformation during the process of construction and then create a good economic and social benefits for construction.