Different Sets of Remediation for Mitigation of Landslides in Hilly Terrains of India

Abstract

The great Himalayan Mountain is a majestic cluster of several numbers of more or less parallel hill ranges intervened by numerous valleys and extended plateaus. The Himalayan landscape, as said by expert geologists, is especially susceptible to landslides. The northward movement of the Indian plates caused continuous stresses on the hill slopes making them weak and prone to landslides. The Himalayan topography, as well as high seismic vulnerability and rainfall in the region, are enlarging the liability to landslides. Landslides or landslips involve a large ground movement due to the gravity forces, which result in total mass wasting of the slope. The landslides are experienced in almost all the national and state highways adjacent to the hill slopes of the Himalayas and hill ranges of India North East, Western Ghats and Nilgiris, Eastern Ghats, Himachal, J&K, Garhwal and Kumaon hill ranges, and Vindhyas. The remedial measures for landslides may be divided into four subcategories; restraint, removal, drainage, and relocation. The retaining structures are designed to retain rock/soil slope that would not naturally be stable at its position. The reinforcement measures include soil nailing and earth reinforcement measures, which involve the insertion of steel rods, metallic strips, geosynthetics, and steel angles to improve the stability of the slope. The reinforcement measures also include the improvement of the mechanical characteristics of the ground through chemical, thermal, or mechanical treatment. The third major remedial measures are drainage measures, which are most effective in a geologic condition that allows interference with the natural water regime. Also, bioengineering techniques in which vegetation is a fundamental part are useful approaches to prevent landslides as they improve slope stability and maintain ecological balance. They are most suitable to be deployed in developing countries because of their cost-effectiveness and environmentally friendly nature. The chosen remedial measures depend upon several factors such as type movement (slide, flow, etc.), type of material (debris, rock, soil, etc.), location of the failure, the process of failures, etc. The several factors that are to be considered before designing and implementing landslides remedial measures will be discussed in the paper. The paper shall be dealt with different sets of remediations such as soil nailing technique, earth reinforced structures, retaining structures, drainage measures, and bioengineering techniques for mitigation of landslides adjacent to roads in Himalayan terrain considering the economic as well as social feasibility, steadiness, and efficiency. Moreover, several advantages and disadvantages of remediation techniques shall be incorporated in the paper.