针对碾压混凝土坝的结构和施工特点 ,采用弹塑性有限元和不等比例降材料强度参数的方法 ,对高碾压混凝土重力坝的渐进破坏过程、破坏机理和极限承载能力进行了分析计算 ,结果表明 ,大坝的破坏失稳表现为沿RCC层面 (包括建基面 )的剪切滑移 ,或表现为从坝体下部下游侧RCC本体开始的大面积压剪屈服为主的与沿RCC层面剪切滑移的组合 ,它取决于大坝的断面形状和RCC层面与块体材料强度的组合情况。因此 ,在研究评价大坝的稳定安全程度时 ,除核算沿关键层面 (或建基面 )的抗滑稳定性外 ,还应考虑坝趾区块体的抗压剪能力。用不等比例降材料强度参数的方法揭示了碾压混凝土坝的破坏规律 ,且结果合理 ,符合实际 According to the structure and construction characteristics of RCC dam, the progressive failure process, failure mechanism and ultimate bearing capacity of RCC gravity dam are analyzed and calculated by using the elastoplastic finite element method and the unequal proportional reduction of material strength parameters. The results show that the failure instability of the dam is characterized by shear slip along the RCC level (including the built-up surface) or by the large area of ​​pressure-shear yielding starting from the RCC body at the lower part of the dam, Shear slip combination depends on the dam’s cross-sectional shape and the combination of RCC and bulk material strength. Therefore, in studying and evaluating the stability and safety of dams, in addition to calculating the anti-sliding stability along the critical level (or the built surface), the compressive shear capacity of the dam toe zone should also be taken into account. The law of failure of RCC dam is revealed by the method of unequal proportioning of material strength parameters, and the result is reasonable and in line with the actual situation