Correlation between Schmidt hardness and coefficient of restitution of rocks

• Estimation of coefficient of restitution (COR) carried out for first time in India.
• Laboratory experiment to find out COR has been done for different rock types.
• Laboratory experiment to find out COR has been performed for various slope angles.
• Effects of Schmidt hardness have been observed on COR for different rock types.
• Empirical relation has been given for COR that will help in rockfall analysis.

Rockfall, like landslide is the disaster that could cause loss of life and property. Exact rockfall trajectories depends upon, slope geometry, slope roughness, static and dynamic friction, rolling resistance, density of rocks as well as the restitution characteristics of rocks. In all these parameters, coefficients of restitution play a vital role to control the trajectories of the rockfall. In this article, an attempt has been made to calculate the coefficient of restitution using laboratory experiments that include dropping of balls of different rock types on the same rock type slabs as well as same type of rock balls on different types of rock slab. Schmidt hardness has been also calculated for both, balls and slabs. Using these experimental results, an effort has been made to establish the relation between coefficient of restitution (COR) and Schmidt hardness.