Assessment of Rockfall Hazard and Stabilization of Rock Slope Surface at the World Heritage Ajanta Cave

Abstract

The assessment of rock fall hazard of a natural rock slope surface with ancient rock cave monuments of historic importance at World-Heritage site of Ajanta in the state of Maharashtra in India, embedded in basaltic rock formation is carried out and presented. In past the site has witnessed many small and large scale rock falls in the form of boulders which could cause the loss to the ancient rock caves of historic importance as well as en-dangering the visitor’s safety. The main cause of the rock fall is dislocation of the boulders from the natural rock surface slopes due to heavy rainfall as well as due to erosion, rock weathering, trees roots widening etc. In the present study, the rock slope surface and dislocated boulders vulnerability to failure risk is carried out with the Rockfall Hazard Rating System (RHRS) in tandem with other empirical approaches available for rock mass classification. The study using rockfall hazard rating system requires tedious field-work due to the involvement of a large number of parameters and long-stretch of the site under question. The detailed field study is carried out for the evaluation of various parameters involved in the RHRS as well as that of various empirical approaches applied. In the case of the cumulative RHRS score is more than 500 which implies that the slope surface or critical boulder site is unstable, prone to failure and need immediate attention for remedial measures. Accordingly, stabilization measures are planned on the priority basis.