古迹坪隧道雪沟斜井喇叭口施工技术

Construction Techniques for the Intersection Part of Xuegou Inclined Shaft with Gujiping Tunnel

文章介绍了对斜井平交口加固,并在平交段设置大型集水井抽排隧道施工涌水;在正洞通过爬坡导洞找顶、挑顶及上台阶反向压顶,进而加固正洞与斜井相交口实现正洞双向作业面,从而确保斜井与正洞交口段施工、结构安全。其施工技术可为喇叭口处于富水、破碎岩体的同类隧道施工提供借鉴。

The horizontal section of inclined shaft at the intersection with main tunnel was reinforced and a large water collecting well was set at shaft bottom to drain water during tunnel construction from the main tunnels.A climbing adit from the shaft bottom was excavated upward to the crown of the main tunnel,enlarged to an upper heading and then to the full section of the main tunnel by bench excavation.Then the intersection part between the main tunnel and inclined shaft was reinforced to realize two working faces in the main tunnel,guaranteeing the safety of construction and structure of the intersection.The practice can be taken for reference by the similar projects in fractured rock with rich water.