Study On Stability Of Borrowed Soil In Ecological Slope Engineering

Strength and scope of human activities'influence on global environment and ecosystem is no longer negligible nowadays. Man exploits many natural resources. He also excavates and backfills rock and soil in the process of engineering construction. The original environment and ecosystem are disturbed or even seriously unbalanced and many bare steep rock slopes are produced by such activities. Hence, while man disturbs the environment, it is important to restore it to its original state. So that ecological slope engineering techniques, such as borrowed soil spraying, hydroseeding, ect. which can green bare steep rock slope are exploited in this situation. Obviously, borrowed soil sprayed on slope surface tends to slide or collapse under actions of rainwash, seepage, gravitational force, earthquake, etc. Therefore, it is urgently needed to establish a stability design method for the soil to estimate the emergency capacity of the soil in constructed ecological slope engineering, or design the stability thickness of the soil with a given design safety factor.In this paper, a study is undertaken on mechanical stability of borrowed soil in ecological slope engineering. Stability tests of borrowed soil without seepage and with parallel-to-slope surface seepage are designed. It is found that failure mode of the soil is a translational sliding surface parallel to the original slope surface along the upper surface of wire nets in indoor simulation tests without seepage and with parallel-to-slope surface seepage. Based on the failure mode, an infinite slope case is assumed and stability analysis of the soil with earthquake and horizontal seepage and with earthquake and parallel-to-slope seepage is carried out, and then general equations with earthquake and horizontal seepage and with earthquake and parallel-to-slope seepage are given for stability thickness of the soil. Stability charts for the soil with earthquake and horizontal seepage and with earthquake and parallel-to-slope seepage are produced after discussion on parameters of the equation...