ABSTRACT
Tunneling through conventional excavation-based drill and blast method offers variety of challenges, especially when it comes to excavation in Himalayan region. Though every drill and blast tunneling project experiences few project specific issues, however, tunneling in mountains with higher overburden typically poses risks of rock squeezing, which may result in rock support deformation. Suki Kinari Hydropower Project (SKHPP) is one of the largest hydropower projects constructed in the northern part of Pakistan. The project includes over 40 KM of tunneling component, being constructed in high altitude mountains with overburden upto 1125.3m. During construction of Head Race Tunnel (HRT), the tunnel went through rock squeezing conditions. This study intends to apprise the event of rock squeezing in HRT, its impacts on provided rock support systems and mitigation measures taken by construction team at project site.
