Abstract: Aiming at the accumulation slope problem which is frequently encountered in the domestic southwest region hydropower project construction, the genetic mechanism and evolution process of accumulation slope was analyzed in detail on base of the piled rock mass characteristics, environmental conditions and engineering geology, and its formation. Generalized geological model has also been restored. Meanwhile, the research is also combined with the geological phenomena and drill core data gained from field displacement exploration. The results show that: the whole accumulation slope is a collapse accumulation, but in the process of formation, large-amount of local destruction occurred in district 1, resulting in geomorphology and internal structural differences between district 1 and district 2. At the same time, the macro-qualitative evaluation and detailed calculations of the stability analysis show that: the whole accumulation body tends to be stable, but the shallow overburden is quite, and in centre there are some local poor stability regions; in order to ensure the normal operation in later stage, and consider the engineering, environmental, and economic factors, foot presser was taken in district 1; cutting slope and retaining wall were taken in district 2. The calculation results can provide the necessary guidance and reasonable basis for the engineering design, and can also provide reference for the analysis of similar projects.

Key words: accumulation body, genetic mechanism, cutting slope and reducing load, retaining wall