Geotechnical Stability Assessment of Road-cut Slopes: A Case Study of Srinagar, Garhwal Himalaya, India

Author: Mukta Sharma, Shivani Sharma, Gaurav Tripathi, Suraj Kumar Singh, Shruti Kanga and Ritambhara K. Upadhyay

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Abstract

The reason for the occurrence of landslides along the cut slopes of road corridors in the Himalayas is the repeated movement along thrust planes, which weakens rock slopes and makes them susceptible to stress and failure. Consequently, landslides are a prevalent phenomenon in this region. Slope stability along mountain roads is a major concern, as slope failures can cause considerable distress to local communities and sever transport links. It is crucial to conduct stability assessments of cut slopes along highways in such areas. The various challenges faced during the study were inaccessible areas making it difficult to collect data and understanding the complex interactions between these factors and developing accurate prediction models is a complex task. Landslides can be triggered by a variety of factors, including, seismic activity, slope instability and human activities. This leads to vagaries of the landslides Despite all the challenges, twenty-two geologically diverse sites along National Highway 58 (A significant transportation route for pilgrims in the Garhwal Himalaya.) from a 17 km stretch between Srinagar and Sirobagarh were selected for detailed geological and geotechnical analysis and evaluation of slope stability using rock mass classification methods, kinematic analysis and numerical modeling. To evaluate the strength of the rock mass for stability assessment, the geological strength index and rock mass rating were employed. Subsequently, the slope mass rating and continuous slope mass rating were determined. The identification of potential unfavorable planes was carried out using kinematic analysis. Furthermore, the stability of three major landslide zones in the area was critically analyzed using large scale mapping with the help of total station. The evaluated values of SMR, CSMR confirm the poor geotechnical properties of a few of the locations and this is corroborated with the field conditions. The results obtained from the study show the weak planes along which the probability of landslides is more and concrete measures can be taken to stabilize those slopes through the concrete walls, mesh, etc.

Keywords

Road Cut Slopes, SMR, CSMR, Kinematic Analysis, Total Station, Topography

Conclusion

In determining the quality of a rock mass, RMR and GSI play vital roles, and our findings are consistent with that existing understanding. SMR and CSMR values provide the most precise evaluation of the slope stability grades. Kinematic analysis helps identifying planes of weakness and this information can further be utilized for planning mitigation measures to avoid landslides in such zones. Slope stability along mountain roads is a significant concern due to the potential for slope failures, which can result in traffic disruptions and the loss of property and/or life. Appropriate landslide mitigation strategies should be carried out based on the findings and recommendations of geotechnical experts. A fundamental technique for the stabilization of a slope is to improve the surface and subsurface drainage conditions. Undesirable surface waters should be drained into natural stream channels using lined drains or diverted to sites where running water will not affect the area. In addition to the above geotechnical approaches, suitable bio-remedial strategies need to be adopted, such as planting along the exposed areas that result from excavation for the widening of roads, as these areas are susceptible to saturation during the rainy season.

References

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How to cite this article

Mukta Sharma, Shivani Sharma, Gaurav Tripathi, Suraj Kumar Singh, Shruti Kanga and Ritambhara K. Upadhyay (2023). Geotechnical Stability Assessment of Road-cut Slopes: A Case Study of Srinagar, Garhwal Himalaya, India. Biological Forum – An International Journal, 15(5): 1071-1080.