Establishing a technical framework for preventing overtopping failure of earth-rock dams in small and medium-sized reservoirs

Li Hong'en; Wang Fang; Wang Xuebing; Zhang Zhu

doi:10.3969/j.issn.1000-1123.2025.06.005

Abstract：In recent years,several instances where small and medium-sized reservoirs with earth-rock dams experienced overtopping without subsequent failure have challenged the traditional notion that"overtopping leads to inevitable breaching".For earth-rock dams with low water heads and minimal downstream impact,appropriate dam surface protection and discharge technologies can delay the overtopping failure process.This not only enhances the dam's capacity to withstand floods exceeding standard levels but also provides valuable time for downstream evacuations.Based on the characteristics of recent overtopping incidents in typical reservoir dams,this paper reviews advancements in design flood calculation methods,engineering measures,emergency response technologies,and risk monitoring and early warning systems to improve the overtopping failure resistance of small and medium-sized earth-rock dams.Key technical challenges identified include defining the concept of floods exceeding standard levels in changing environments,understanding overtopping erosion characteristics and failure mechanisms under multiple factors,developing new dam surface protection structures,enhancing flood discharge capacity,and improving emergency response technologies and equipment.To establish a technical framework for preventing overtopping failure in small and medium-sized reservoirs with earth-rock dams,this paper proposes strategies focusing on design flood calculation and standard determination methods in changing environments,simulation of overtopping failure and determination of critical thresholds,development of new dam surface protection structures and technologies to enhance flood discharge capacity,and integration and demonstration of emergency response technologies and equipment.The goal is to provide technical support for enhancing the resilience and risk prevention capabilities of small and medium-sized reservoir earth-rock dam projects.