Study on Reliability of Rock Penetration Depth of Subway Underground Tunnel Through Strongly Weathered Diorite
The study aims to assess the reliability of the excavation depth for subway tunnels constructed by the cut-and-cover method during their crossing of highly weathered diorite formations.A tunnel in Jinan,China,was used as a case study to investigate tunnel settlement behavior.Ansys numerical modeling and reliability analysis modules,in combination with Monte Carlo sampling techniques,were utilized.Geotechnical parameters were treated as random variables to analyze surface settlement characteristics when the tunnel was embedded to a minimum depth within the highly weathered diorite.The results show that the maximum vertical displacement of surface settlement not exceeding 25mm had a high probability of 0.942,meeting safety standards.A scientific reliability assessment method is provided for subway tunnels constructed by the cut-and-cover method when crossing complex geological formations.It aids in the optimization of design and construction strategies,ensuring tunnel structural stability and reducing construction risks.The study holds significant practical implications for subway engineering projects.