某大型堆积体边坡成因机制分析及治理措施研究

Research on genetic mechanism and treatment method of some large-scale accumulation slope

针对我国西南地区水电工程建设中经常遇到的堆积体边坡问题,以堆积体边坡的岩体结构特征及工程地质、环境条件为基础,结合现场踏勘在地表、平硐中看到的地质现象和钻孔岩芯资料,详细地分析了堆积体边坡的成因机制和演化过程,并恢复出其形成的概化地质模型。结果显示,堆积体边坡整体为崩塌堆积物,但在形成过程中堆积体一区中上部发生了较大方量的局部破坏,导致了堆积体一、二区地貌和内部结构的差异。对堆积体边坡的稳定性进行了宏观定性评价和详细计算分析,结果表明堆积体整体趋于稳定,但覆盖层浅、中部存在局部稳定性较差的区域。为保证工程的后期正常运营,在综合考虑工程、环境、经济等方面因素的基础上,对堆积体一区采取压脚的处理方式,二区采取削坡减载加挡土墙的处理方式。分析计算成果为工程设计提供了必需的指导和合理的依据,同时也可为类似工程的分析提供参考。

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.