河咀村文昌阁滑坡的特征与成因分析

兰州市西固区河咀村文昌阁滑坡是农业提水灌溉引起地下水富集诱发黄土台塬斜坡失稳变形的典型例证.文昌阁滑坡是一巨型黄土-基岩滑坡,具有低速、近程、孕育周期长等特征,滑坡发育历时3年半,经历了蠕动、微动、剧滑3个阶段.在滑坡形成的环境地质条件、变形特征、发育过程和成因分析的基础上,通过与邻近地区滑坡灾害的对比研究发现,由于提水灌溉引起地下水富集,诱发斜坡大范围变形破坏,在甘肃省中、东部黄土台塬及河流高阶地地区具有普遍性.从开始提水灌溉到斜坡失稳、灾害频发,大致经历20 a的孕育过程,目前,兰州市达家台台缘地区已进入灾害高发期.

CHARACTER AND MECHANISM ANALYSIS OF THE LANDSLIDE IN WENCHANG MOUNTAIN, HEZUI VILLAGE

The landslide in Wenchang mourtain, Hezui village is a typical examplification of slope deformation caused by irrigational water concentrated in the loess terrace, and it is a huge loess\|bedrock landslide with the principal characteristics of slow velocity, short displacement and long developing period. The developing period of the landslide lasts about three and half years, and it can be divided into three periods of creepage, short moving and tremendous sliding. Based on the analysis of the environmental geological conditon, the deforming mechanism, the developing process and, the cause of the landslide, the following conclusions were given out, after the contrast research of the slope deformation in loess terraces caused by irrigational water concentration in middle\|east Gansu province. The developing period of landslide hazards last about 20 years from the beginning of irrigation; Nowadays, the landslide hazards in Da Jia terrace is very frequent.