Zhengkang High Speed Rail No. 7 Division 2 Baokang Tunnel has an import mileage of D1K499 + 420, an exit mileage of D1K513 + 980, a total length of 1,460m, and a dual-line tunnel with a design speed of 350km / h. The maximum buried depth of the tunnel is 504m. The entrance is near the abutment and the exit is connected to the subgrade. The geological conditions of the tunnel are shale and sandstone. The whole tunnel is mostly surrounded by Grade Ⅳ and Ⅴ surrounding rocks, and partially accompanied by Grade Ⅲ surrounding rocks. The rock mass is broken, joint fissures are developed, weathering is more intense, and self-stabilizing ability is poor. In addition to the traditional construction methods for the entrance, exit and ceiling sections of the tunnel, the remaining sections are constructed using the full-section method. At the same time, large-scale mechanized supporting operations such as three-arm rock drilling trolleys, three-arm arch installation machines, and wet spray robots are used. The total construction period is 66 months.
The design profile, combined with the "new idea" construction concept, by using the characteristics of high strength, light weight, easy anchoring, good reinforcement effect and economical practicality of glass fiber anchors, it has a good advance pre-reinforcement ability in front of the tunnel palm face. . In addition, the use of three-arm rock drilling trolley, wet spray manipulator, mobile grouting operation platform and other machinery, on the premise of increasing the stability of the palm face, laid a good foundation for the tunnel excavation construction. It can achieve the purpose of convenient excavation, reducing construction workers, reducing labor intensity, reducing construction safety risks, and fast and efficient construction.
Project Application Type:
Support engineering-application of new Italian
Easy to cut and corrosion resistant