Long-term assessment of creep and water effects on tunnel lining loads in weak rocks using displacement-based direct back analysis: an example from northwest of Iran

Abstract The time-dependent stability of tunnels is an important and challenging topic, mainly when the tunnel excavated in incompetent weak rocks. creep property rock one crucial mechanical properties main factor affecting long-term masses. Also, water as environmental influences both short-term behavior rocks causes geotechnical engineering disasters, such collapse, slope sliding, surface subsidence, etc. In this research, effects rock’s underground on Shibli were analyzed. Geological maps reports show a highly jointed condition surrounding which have been crushed by two orogenic stages. Burger-creep visco-plastic model was used to simulate host behavior. model's parameters adopted based displacement-based direct back analysis technique using univariate optimization algorithm. addition, influence assessed under varying table. Support capability diagrams evaluate loading created tunnel’s permanent lining due mass water. This study suggests that rock's significantly affect tunnels. Results induced stresses are more considerable spring-line. increasing 20 m table approximately decreases ten years time at fault zone. Article highlights Rocks Displacement-based algorithm determine CVISC model’s properties. Increasing