德胜隧道软岩严重大变形施工控制技术

Construction Control Technology for Serious Large Deformation of Soft Rock in Desheng Tunnel

德胜隧道位于区域大断裂带内,处于极高地应力环境,在千枚岩地段施工中发生了严重的软岩大变形。文中针对大变形发生特征开展原因分析,采用圆形结构断面、增加预留变形量、长短锚杆结合、双层型钢拱架、长锁脚锚管、径向注浆等组合措施,并提出二次支护、长锚杆、二次衬砌合理施作时机,有效控制了软岩大变形。

Desheng Tunnel is located in the regional large fault zone and in the extremely high crustal stress environment.During construction,serious large deformation of soft rock occurred in the phyllite section.According to the characteristics of large deformation,the cause analysis was carried out,and the combined measures were adopted,such as circular structure section,increase of reserved deformation,combination of long and short bolts,double-layer steel arch,long locking anchor pipe,and radial grouting,etc.In addition,the reasonable construction time of secondary support,long bolts,and secondary lining was proposed to effectively control the large deformation of soft rock.