Abstract
Collapse is one of the most dangerous geological disasters in tunnel construction, and it is an urgent engineering problem which needs to be solved. Taking the collapse of the top of an actual tunnel face as an example, through field investigation and theoretical calculation methods, the mechanism of tunnel collapse was studied, and the treatment and evaluation of the collapse area were proposed based on field monitoring data. The results show that the extrusion and bulging deformation on the palm surface and the tensile fracture in the top inclined stratum led to the shear slip of the block along the structural surface and the local collapse of the surrounding rock. Based on the block theory, the potential unstable block at the top of the tunnel was successfully identified, and the treatment method of ‘protecting before filling and then digging’ was proposed. The comprehensive treatment measures of advance bolts, steel arch support, collapse backfill, and step excavation were adopted, with on-site monitoring followed up step by step. Based on the analysis of surrounding rock deformation and stress characteristics, in this paper we demonstrate that the treatment effects of the collapse area are good, and ensure the safety and smooth progress of construction. The proposed treatment method achieved the expected goal and was shown to be able to provide successful treatment for similar collapse cases of tunnel engineering.
Highlights
Geological disasters such as collapses, water inrush, and landslides are thorny problems in engineering construction [1,2,3]
Zheng et al [12] studied the mechanism of tunnel collapse based on model tests and the influence of the arch effect and water inrush on a lining structure using numerical simulation methods
Based on a statistical analysis of a large number of tunnel collapse cases, Wang et al [17] proposed that tunnel depth, groundwater, surrounding rock level, and construction measures were the main factors affecting tunnel collapse; the influence of rainfall conditions on tunnel collapse was studied through model tests, which indicated that groundwater has a significant impact on tunnel collapse
Summary
Geological disasters such as collapses, water inrush, and landslides are thorny problems in engineering construction [1,2,3]. Zheng et al [12] studied the mechanism of tunnel collapse based on model tests and the influence of the arch effect and water inrush on a lining structure using numerical simulation methods. Based on a statistical analysis of a large number of tunnel collapse cases, Wang et al [17] proposed that tunnel depth, groundwater, surrounding rock level, and construction measures were the main factors affecting tunnel collapse; the influence of rainfall conditions on tunnel collapse was studied through model tests, which indicated that groundwater has a significant impact on tunnel collapse. Current research mainly focuses on the mechanism and influencing factors for the collapse of tunnels at a shallow depth, in soft rock, rich water, and other adverse geological conditions, while few studies have reported on the collapse of deeply buried hard rock tunnels. The proposed method could provide engineering experience for similar projects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
