新疆伊犁黄土工程地质特征及致灾机理研究综述

    MECHANICAL PROPERTIES AND DISASTER-CAUSING MECHANISM OF LOESS IN ILI, XINJIANG, CHINA

    • 摘要: 伊犁黄土具有强湿陷性、高易溶盐含量等地域性特征,成为伊犁谷地地质灾害发育的重要物质基础。本文在总结伊犁谷地黄土的成因、分布、成分及黄土地质灾害分布特征的基础上,分析了含水率、干密度、垂直荷载、易溶盐含量、基质吸力及冻融循环次数对伊犁黄土水-力学特性的影响,总结了伊犁黄土滑坡灾害类型及特性。受谷地喇叭状地形及气候影响,伊犁黄土埋深呈中部深两侧浅分布,粒径由西向东逐渐变细,与黄土滑坡灾害分布呈正相关。伊犁黄土湿陷性受控于垂直荷载,在含水率为8% ~10%达到最大,与干密度呈负相关。伊犁黄土湿陷性与垂直荷载关系符合Biphasic Hill方程。易溶盐含量对伊犁黄土抗剪强度具有重要影响,与黏聚力呈负相关;冻融循环次数增大会导致黄土结构破坏、裂隙率快速增大,伊犁黄土渗透系数先增后减,黏聚力快速减少。从地质结构、动力条件、滑动机制等方面将伊犁黄土滑坡进行分类总结;分别对不同动力成因下的黄土滑坡灾变机理进行阐述。研究成果对伊犁黄土滑坡研究和防治、滑坡灾害预测具有一定的指导意义和适用价值。

       

      Abstract: Ili loess has regional characteristics such as strong collapsibility and high soluble salt content and has become an important basis for the development of geological disasters in the Ili Valley. Failure mechanism of loess landslides is controlled by the geological properties of the loess and the special environment of the Ili Valley. Ili loess has its own uniqueness due to its unique geographical location and climatic conditions. In this paper, the distribution, genesis and development characteristics of Ili loess are summarized. The effects of moisture content, dry density, vertical load, soluble salt content, matrix suction and freeze-thaw cycles on the hydro-mechanical characteristics of Ili loess are analyzed in detail with indoor experiment, CT scanning technology, SEM and other methods. The Ili loess landslide was classified and summarized from theaspects of geological structure, dynamic conditions and sliding mechanism. The catastrophic mechanism of loess landslide under different dynamic causes was elaborated. It has certain guiding significance and applicable value for the research and prevention of Ili loess landslide and landslide disaster earch and prevention of Ili loess landslide disasters.

       

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