Stability Analysis Method for Initial Support Structure of Tunnel in Swelling Loess

The stability of tunnel is greatly affected by the changes in volume and strength swelling loess caused humidification. Quantitative reflection influence humidification on mechanical model has important engineering significance for design support structures. Based fact that parameters related to are functions water content, content was introduced into classical surrounding rock–support model, a safety factor employed index stability. Thus, analysis framework established considering softening loess. In an case, theoretical models this paper were investigate change rules rock deformation factor, sensitivity tunneling Analysis results showed response curves factors obtained consistent with actual situation, predicted maximum radial displacement free face close measured value. These indicate applicable initial tunnel.