Abstract:

 Due to the sudden encountering of karst caves, collapse occurs at YK37+671 of Jucishan tunnel. During the treatment of the collapse, chimney collapse occurs. In order to minimize the construction influence and to ensure the operation safety of the tunnel, collapse treatment technologies, such as consolidating the collapse body by grouting from the ground surface, long pipe roof installed without excavating working chamber, grouted small pipe forepoling, excavation by CRD method, treatment of clearance interfering section after the lining structure on both sides of the collapse area is strengthened, ground surface subsidence treatment, advance geology forecasting and monitoring, are used, which ensures that the tunnel driving passes through the collapse area successfully. The paper can provide reference for the collapse treatment of other tunnels in the future.

Key words:  tunnel, collapsechimney collapseclearance interfering sectionlong pipe roofconstruction technology