Stability Evaluation of Engineered Slopes Using Coupled Empirical and Analytical Approach Along NH-9, Lesser Himalayas, India
摘要
The development of road projects in hilly terrains has increasingly led to rampant slope failures, highlighting the need for slope stability studies to prevent the loss of human lives and economic assets. In many developing nations, the challenges of safe slope design in hilly regions emphasize the importance of ensuring stability appraisal of engineered slopes. To provide smooth travel and safety design, the road-cut slopes need to be monitored for stability assessment. The study presents stability appraisal of 36 susceptible engineered slopes along National Highway-9 from Pithoragarh to Jauljibi using kinematic analysis, slope mass rating (SMR) and its derivatives, including continuous slope mass rating (CoSMR) and Chinese slope mass rating (ChSMR). The kinematic analysis was performed to reckon the potential for various discontinuity-controlled failures and computation of factor of safety (FoS) for probable failures. Out of all the studied slopes, 11 slopes showed planar failure, 18 slopes showed wedge-type failure, and 7 slopes showed a combination of more than one type of failure. The stability classes of SMR, CoSMR and ChSMR show that 11%, 17% and 14% lie in completely unstable category, 45%, 39% and 25% in unstable category, 33%, 33% and 42% in partially stable category and 11%, 11% and 19% in stable category. FoS results show that 61% slopes are unstable, 16% as critically stable and 23% as stable. The necessary remedial measures are provided with quick representation using modified chart and guidelines proposed by Romana. The spatial variability of stability classes was analysed, categorized and depicted CoSMR, ChSMR and FoS values using Geographic Information System (GIS). The R2 values are 0.70 for SMR/CoSMR and 0.65 for ChSMR, indicating a sound correlation among outcomes obtained by different proxies.