A Semi-Empirical Approach for Rockfall Prediction Along the Lengpui-Aizawl Highway Mizoram, India

The Lengpui-Aizawl highway in the Northeastern part of India has witnessed several rockfall events in the past decades. This is the only highway that connects the Airport to the city. Considering the importance of the highway, semi-empirical equations were developed to predict the rockfall output parameters such as bounce height, velocity and kinetic energy. The five major input parameters, such as slope height, slope-angle, slope-roughness, block-weight and coefficient of restitution that can affect the rockfall, have been considered for the parametric study. The paper includes detailed site investigation, laboratory investigation and rockfall modelling to estimate the generalised equations based on multivariate linear regression analysis. The site survey includes topographical and geological details of 13 rock slopes along the Lengpui-Aizawl highway. The coefficient of restitution was estimated in the laboratory using a fabricated rockfall setup. Further, 243 modellings were performed to analyse the data and develop the generalised rockfall equations. These generalised equations will help the field engineers to predict the outcome of the rockfall activity and help design suitable mitigative measures.