Effect of slope protection using concrete waste on slope stability during rainfall

Abstract

Due to climate change, higher rainfall infiltration is expected in the future and it may cause a slope failure. Simultaneously, infrastructure construction and urban redevelopment are rapidly generating large amounts of construction and demolition waste that also contributes to global climate change. To ensure the stability of the slope, it is important to find cost-effective and environmentally sustainable alternatives. Waste material such as recycled concrete aggregate (RCA) can be utilized to protect the slope. The use of RCA for slope protection is that it can be used as a material for the capillary barrier system. The objective of this paper is to investigate the characteristics of pore-water pressure distribution and slope stability with the application of RCA protection during rainfall in comparison with the original slope through numerical modeling. The SWCC for the soil and RCA materials were measured using a high-suction polymer sensor (HSPS) and Tempe cell, respectively. The volume changes of the soil were measured using 3D scanner. SEEP/W was used to conduct the seepage analyses and obtain the change of pore-water pressure distribution due to rainfall infiltration. SLOPE/W was used to evaluate the stability of the slope with different climatic conditions. The use of recycled concrete aggregate (RCA) for slope protection from rainfall infiltration has been investigated in this paper. The results showed that the safety factor of the slope increased with the addition of RCA protection. Rainfall infiltration causes a reduction in soil suction and hence reduces soil shear strength, the safety factor will also decrease since the soil will become weaker.

Keywords

• Unsaturated Soil
• Soil-water characteristic curve
• Concrete waste
• Rainfall-induced slope failure