Design of Tunnel in Weak Geology- A Case Study of Kathmandu University Research Tunnel

Abstract

The study focuses on the design of a tunnel in weak geology in Nepal, using the Kathmandu University Research Tunnel as a case study. The geometrical design of the 234-meter-long tunnel has been completed, and an empirical method has been used for estimating the support requirements. A 2D finite element numerical analysis was performed using RS2 to assess the stability of the tunnel. Squeezing potential was evaluated using the empirical method, and the results indicate that there is no significant risk of tunnel squeezing due to the low overburden depth. The support system, consisting of rock bolts, Shotcrete, and steel ribs, was used in the numerical analysis. The results show that the provided support is sufficient to withstand the rock mass stress, as demonstrated by the support capacity plots. Based on these results, the support system has been recommended for use during the construction of the tunnel.