Stability of road cut slopes along NH-44 in the Kashmir Himalayas: a study using slope mass rating and kinematic analysis

Abstract

This study assesses the slope stability of various road cut slopes along National Highway (NH-44), which runs from Jawahar Tunnel Banihal to Ramban in the Kashmir Himalaya, India. Frequent landslides along NH-44 disrupt infrastructure, transportation, and the region’s development and economy. Ongoing road widening, tunneling activities, and heavy rainfall during the monsoon season lead to regular slope failures and blockages of NH-44. A comprehensive field survey was conducted to collect lithological and structural data for rock mass characterization, kinematic analysis, and slope stability evaluation. A total of 27 road cut slopes were analyzed for Rock Mass Rating (RMR) and Slope Mass Rating (SMR), while 48 sites were assessed for kinematic analysis. The area was divided into four domains (D-1, D-2, D-3, and D-4) based on major structural discontinuities for detailed study and analysis. The RMR values ranged from 8 to 82 (Very Poor to Very Good), while SMR values ranged from 7 to 82 (Very Bad to Very Good). Kinematic analysis identified that most failures are due to planar and wedge failures, with some toppling failures. The slopes, ranging from moderately stable to unstable, are prone to instability and collapse, especially due to changes in slope morphometry and frequent rainfall. The region lies within a tectonically active zone, making the slopes inherently unstable. This study’s integrated approach provides valuable insights into hazard mitigation, highlighting critical failure-prone areas and supporting better planning for infrastructure and sustainable development in the Himalayan region.