Rock Mass Classification Systems and Kinematic Analysis of Slates From Dir Group, Nw, Himalaya, Pakistan; Implication for Slope Stability

Abstract

Slope stability is an important issue for the construction of roads on hill slopes. 24 slopes cuts have been investigated to determine the slope instability issues and mode of failure along the newly constructed road of Dir-Sheringal Khyber-Pakhtunkhwa, Pakistan. The major rocks are slates and tuffaceous siltstone which are weak to moderately strong in strength. The main objective of this study is to assess the application of rock mass classification systems and kinematic analysis which affects the slopes. The investigation shows that rock mass rating (RMR-basic), and slope mass rating (SMR) values range from 0 to 73 which is poor to normal while geological strength index (GSI) analysis classified the rock mass from poor to good conditions. The Kinematic analysis shows that three types (plane, wedge and topple) of failure mode are present in these slopes. Most of the slopes are unstable and weak where perspective tools and proper installation provide support and prevent future failure. This study shows a good relationship between RMR-basic, SMR, and GSI for different locations.

Geotechnical Assessment of Rock Slope Stability Using Kinematic and Limit Equilibrium Analysis for Safety Evaluation

“…Each sample was placed in a triaxial cell and subjected to 0.20 KN/s of steady vertical pressure until failure (see Figure 2f). ISRM-recommended laboratory testing methods were followed [40]. Figure 2e depicts an RMT-150 rock mechanics testing machine used to perform triaxial tests.…”

“…Slope height has an inverse relationship with the FOS. Shear strains will increase as slope height (h) increases; as a result, FOS will decline [39,40].…”