达康三线隧道出口滑塌体的治理

达康隧道出口是三线隧道，开挖断面积大，地质条件差。由于洞口左侧山体出现滑塌，导致已施作的初支变形侵限。经研究采用在清理滑塌体后施作抗滑桩和板桩墙及施作锚杆框架梁对边坡仰坡进行防护，然后施作一段明洞，暗洞改用大管棚超前预支护、双侧壁导坑法开挖进洞、撤换被挤压变形的初期支护。实践证明该处理方法可行，顺利通过了滑坡段，保证了该隧道后期正常施工。

On the Treatment of the Sliding and Collapsing Bodies at the Outlet of the Dakang Three-Line Tunnel

Being large in the excavation section and poor in geological conditions, the Dakang Tunnel at the outlet is a three-line one difficult to build. Because the left-side body of the mountain at the outlet slides and collapses,the finished initial supporting part of the tunnel is deformed and goes beyond the limits. After a careful study, anti-slide piles, the plate wall and the beams of the anchor-stock framework are provided to protect the side slopes and the inverted slope after the sliding and collapsing bodies are removed. Then, a length of open-cut tunnel is built, while the technique of advanced large-tube-shed support is performed during the construction of the covered section of the tunnel, and the method of the dual side-wall-pilot-holes is carried out when digging into the tunnel, with the pressure-deformed initial supports removed and re- placed. Practice proves the feasibility of the treating method, which helps the smooth and safe excavation through the sliding section and ensures the normal performance of the construction of the following sections of the tunnel.