Disintegration Resistance of Steep-Rocky-Slope Wall-Hanging Soil Based on High-Performance Ester Materials

Abstract

Ecological restoration is difficult on the steep rocky slopes (SRS) in rainy areas in South China that experience severe soil erosion. The disintegration resistance of steep-rocky-slope wall-hanging soil (SRSWS) is a crucial topic in the field of new ecological restoration. The formation of a transient saturated zone of wall-hanging soil (WS) under high-intensity rainfall can easily lead to soil disintegration. The subsequent rain erosion can cause the loss of growth substrate required for early plants, resulting in a poor greening effect or even landslides. Therefore, improving the disintegration resistance of WS and ensuring the stability of the early-plant-growth environment are at the core of SRS protection. In this paper, structural and static underwater disintegration tests of red soil modified by high-performance ester materials (HEMs) were carried out. According to the damage ratio of the soil structure and the disintegration rate and disintegration amount of red soil, the structural properties and disintegration resistance of improved red soil were quantitatively measured. The results show that absorbent HEMs generally increased the content of water-stable aggregates (WAs) in red soil. However, when the content was excessively large, it destroyed the WAs and accelerated the overall disintegration rate and amount. Based on the structure and disintegration resistance test of red soil, optimal pro-portions of adhesive HEMs of 10 g·m−3 and absorbent HEMs of 80 g·m−3 were obtained. The optimal proportions obtained from the above experiments showed good adaptability and an improvement effect on the structural properties and disintegration resistance of red soil. This solves the problem of the growth substrate required for early plant disintegration and loss in water. This paper provides a theoretical and experimental basis for the ecological restoration of SRSWS with disintegration resistance. It has guiding significance for the steady progress of greening construction on SRS sites.