Resource utilization of debris flow deposits in the gullies along Dujiangyan - Wenchuan Expressway, China

Abstract

Abstract The alpine valley region in southwest China is susceptible to frequent debris flow disasters, which cause the accumulation of large amounts of solid materials in the gullies and rivers, particularly behind check dams. These deposits not only reduce the storage capacity of the dams but also pose a potential threat to downstream villages if the dams fail. How to deal with these deposits presents a scientific challenge for geologists. This study focuses on investigating the silting circumstances of the structures and proposes resource utilization of debris flow deposits in the gullies along the Dujiangyan - Wenchuan Expressway. The results showed that most of the dam storage was filled with granite boulders and silt soils, rendering the dams inoperative during subsequent debris flows. As granite is a high-quality construction material suitable for building, landscaping, and decoration, which presents an opportunity for disaster reduction and economic development through resource utilization. However, improper excavations could result in associated problems, including damage to dam foundations caused by headward erosion of debris flows, increased debris flow velocity due to a steepened excavated slope, and an enhancement of the impact force on the dam. Therefore, it is crucial to pay close attention to and conduct in-depth research on these issues.