Rescue technology of the jamming accident for the double-shield TBM in complex geological conditions: A case study

Abstract

More than 80 TBM jamming accidents had been recorded in the Water Diversion Project from the Hongyan River to the Shitou River in Shan’xi Province, China, resulting in substantial losses. This paper aims to investigate the rescue technology for the jamming accidents of the double-shield TBM in the project through a five-year geotechnical in-situ investigation. Firstly, the engineering background, the geological and hydrological conditions, the construction method, the possible jamming hazards, and the support system is introduced in detail. Then, the jamming accidents of the double-shield TBM are classified into the five kinds in total, namely, the shield jamming accident, the cutter head jamming accident, the jamming accident in the fault fracture zone, the jamming accident in the large-deformation section, and the jamming accident at water-rich and severely weathered broken rock section. And corresponding causes of accidents is analyzed at the same time. Afterward, the rescue technology adopted for the typical jamming accidents is explored, including the small pilot tunnel scheme, the advanced grouting scheme, the advanced large pipe shed scheme, the circular excavation scheme, and the auxiliary tunnel scheme. Finally, the prevent approaches for the jamming accident of the TBM are proposed, hoping to guide the same projects.