ABSTRACT

The slope instability may result due to change in stress conditions, the rise in ground­ water table and rainfall. Similarly, many slopes that have been stable for many years may suddenly fail due to changes in the slope geometry, weak soil shear strength, and external forces effect. This is a crucial problem as it may destroy buildings, damage roads, and even results in the loss of human life. Slope failures occur without any warning and carry destructive energy. So it is imperative to understand the slope failure mechanics and adopt safety measures to prevent such sort of slope failures. The aim of this research study is to analyze the stability of slope at different angles in silty soil and propose a method to stabilize it. The proposed methods to stabilize the existing slope are replacing soil-cement (7% by weight) by vertical layering and layering along the slope. Limit equilibrium method was used to analyze the slopes. Morgenstern and Price's method was used to determine the factor of safety of slope against failure. Mohr-Coulomb failure criterion was adopted to capture soil behavior. The minimum factors of safety of the existing slopes were computed less than 1.5 which is acceptable for design of slope. It implies that the existing slopes were on verge of failure. The factor of safety improved significantly after replacing soil cement by both methods. Among the two methods, it was revealed that the layering along slope meth<l d of soil replacement was most economical and easy to be executed at the site