Study on tunnel safety incipient danger and countermeasures optimization in high-terrace folk house in Kashgar city

Chen Wang, Dengfeng Yang and

Abstract

The high-terrace folk house in Kashgar has a widely distribution of tunnels and underground storage space under the building, which bring a great incipient danger to the stability of the building and the slope. Two typical incipient dangerous working condition of tunnel stability are studied with the Realistic Failure Process Analysis (RFPA) code, considering collapsible loess mechanical property of heterogeneous distribution characteristics. In RFPA code, elastic damage mechanics is a method used for describing the constitutive law of the meso-level element, and the maximum tensile strain criterion and the Mohr–Coulomb criterion are utilized as the damage threshold. In the numerical modeling with RFPA, the acoustic emission (AE) event rate is employed as the criterion to intuitively describe the dynamic evolution of soil mesoscopic damage - fracture extension - fracture plane formation -local or overall instability for tunnels and underground storage space failure. The maximum risk and critical condition of the two kinds of working condition are obtained. In view of the complexity and difficulty of the tunnels backfill work in Kashgar, two feasible suggestions are put forward.