Investigating Performance of Nature-Based Soil Cover System for Back Slope: a Case Study of Back Slope of Highway No. 1192

Abstract

Erosion problem of back slope occurs frequently during heavy rainfall. This paper presents the behaviour of nature-based slope cover systems, namely 1) vetiver system with bamboo fence, 2) erosion control blanket and erosion control log, 3) capillary barrier system at the back slope of highway no. 1192 in Chiangmai province. The 45 degree slope was about 10m high, consist of residual granitic soil which was highly erodible. The monitoring results of soil moisture, pore water pressure, suction and rainfall indicate that the capillary barrier system that utilizes biochar and recycled asphalt aggregate performed the best, as shown by least erosion and highest suction preserved in the slope. It was also found that the screw pile and vegetated flapped soil bag could be effectively installed at the toe to reduce the toe erosion as compared to the slope section without the stabilizing system.