Abstract：A rockfill dam with a crown height of 315 meters has been proposed as the water retention structure for a large hydropower station. The RS accumulation body is located approximately 5.4 km upstream of the dam，with an estimated volume exceeding 47 million cubic meters. The stability of this accumulation body is，therefore，a significant concern for the development of this project，prompting comprehensive studies. This paper presents a summary of the research conducted，focusing on the formulation and associated stability of the accumulation body. Site investigations have revealed that the accumulation body can be divided into two distinct parts based on the characteristics of the granular materials? compositions and structures. The lower part is formed from rock falls originating from the cliff behind，alluvial deposits along the river，and ice-water induced muddy flow from two nearby gullies. In contrast，the upper part exhibits an interbedded structure comprising granular materials，both glued and unglued，which is significantly different from that of the lower part and suggests a rare formation known as ice-snow sheet flow. These materials were transported by melting ice and snow and deposited interactively on the surface due to historical climate changes. Qualitative analyses and numerical modeling were subsequently conducted to assess the stability of the RS accumulation body. The findings indicate that the lower part is relatively stable，contributing positively to the overall stability of the entire structure. However，the potential for material sliding along the bedding in the upper part is expected to increase with the impoundment of the reservoir. The numerical model suggests a maximum failure volume of approximately 9 million cubic meters，which can be utilized as input for studies related to swell risk assessment and engineering design measures.
杜帅群1，湛正刚1，李 杨2，郑雪玉1，朱焕春2，袁宇坤2. RS堆积体的成因机制及稳定性分析[J]. 岩石力学与工程学报, 2025, 44(S1): 21-30.
DU Shuaiqun1，ZHAN Zhenggang1，LI Yang2，ZHENG Xueyu1，ZHU Huanchun2，YUAN Yukun2. Analysis on the formation mechanism and stability of the RS accumulation body. , 2025, 44(S1): 21-30.
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2025, Vol. 44 
