不同工法在炭质片岩隧道大变形控制中的应用研究

Study of Application of Different Construction Methods to Tunnel Large-deformation Control in Carbonaceous Slate

隧道施工工法在控制位移变形、资源投入、工程进度、施工成本以及保证施工和结构安全等方面有着重要的作用。为解决炭质片岩隧道修建过程中存在的大变形、坍塌、初期支护及二次衬砌开裂等问题,以谷竹高速公路宴家隧道、关垭子隧道为例,对复杂地质条件下,含绢云母炭质片岩隧道施工工法的适用性进行了研究。通过对软岩隧道施工工法进行分析,并结合工程的地质特征和隧道的断面大小对施工工法进行了优选,经过现场实际验证,说明三台阶法、CRD法、双侧壁导坑法能有效控制围岩大变形,且控制能力依次增强,另外超前预支护对预防隧道坍塌有显著的安全保障作用。

The tunnel construction method plays an important role in deformation/displacement control,organization,cost,schedule and structural safety. The applicabilities of different construction methods to Yanjia Tunnel and Guanyazi Tunnel on Guzhu Highway in sericite carbonaceous slate are studied,so as to solve the problems of large deformation,collapse and cracking of primary support and secondary lining. According to construction method analysis and optimization results,the three-bench method,CRD method and double-side drift method show good applicability to large deformation control. Besides,advance pre-support can avoid tunnel collapse obviously.