Prediction of tunnel ground deformation – A case study from Western Himalaya, India

This study focuses on prediction and analysis of ground deformation during construction of Khari-Banihal Railway Tunnel (KBRT) in the Western Himalayas. KBRT is located in a geologically disturbed area and has undergone multiple phases of deformation. Objective of this study is to identify the key factors influencing tunnel deformation and develop a predictive model using real-time 3D monitoring data and multiple linear regression (MLR) techniques. Motivation behind this study arises from frequent discrepancies observed between anticipated and actual deformation in tunnels, particularly in geologically complex regions with high tectonic activity. The findings suggest that deformation in tunnel walls and crown is influenced by overburden thickness and in-situ stress. Increasing number of support elements and support pressure leads to higher deformation, while longer pull length reduces deformation tendencies. Size of plastic zone around the tunnel also plays a crucial role in deformation. The proposed predictive model improves project planning by enhancing cost and time efficiency.