Research on the comprehensive control technology system of large-scale debris flows in the area affected by strong earthquake in Longmenshan, Sichuan Province

Abstract

In response to the challenges posed by frequent, widespread, long-lasting, large-scale, severe, and difficult-to-control debris flows in strong earthquake areas, this study, based on the results of the National Key R&D Program, investigates dozens of typical mega debris flow gullies in these regions. Through test verification and demonstration engineering application, the characteristics of typical debris flow ditches and their prevention and control engineering effects were studied, leading to the construction of a comprehensive technical system for the prevention and control of mega debris flows in strong earthquake areas. A key technical system for exploration, design, prevention, and control of mega debris flows in strong earthquake areas was formed. The exploration and design system introduced new technologies for identifying earthquake-induced fracturing sources and novel approaches for determining blocking coefficients based on existing exploration technologies. According to the morphology of debris flow valleys in seismic areas, debris flows are classified as narrow and steep or wide and gentle. The key technology system for prevention and control was established to comprehensively discuss and practice key technologies for preventing and controlling debris flows in different valley morphologies. Considering the characteristics of debris flow valleys in the upper, middle, and lower reaches of both narrow and steep or wide and gentle debris flow valleys, a combination of various comprehensive prevention and control measures was proposed. This led to the establishment of a hierarchical control system for major debris flows in seismic areas, from controlling the source to the process and ultimately mitigating disasters. This system not only provides technical support for comprehensive prevention and control of debris flows in seismic areas but also serves as a reference for comprehensive prevention and control of debris flows in non-seismic areas.

Keywords

• debris flow
• strong earthquake areas
• comprehensive control system
• earthquake-induced fracturing sources
• blocking coefficient
• narrow and steep type
• wide and gentle type