黑方台焦家4号黄土滑坡发育特征及滑动机理  

Development characteristics and sliding mechanism of Jiaojia No.4 loess landslide at Heifangtai table-land in Gansu Province

作　　者：巨袁臻 许强[1] 彭大雷[1] 周飞[1] 亓星[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《人民长江》2017年第11期62-67,91,共7页Yangtze River

基　　金：国家重点基础研究计划(973计划)资助项目(2014CB744703);国家创新研究群体科学基金项目(41521002);国家杰出青年科学基金项目(41225011)

摘　　要：20世纪60年代以来,大量的灌溉系统在黄土地区建设运营,解决了农业的干旱问题,但同时灌溉也诱发了大量的滑坡。其中,2015年1月28日20:00,甘肃省永靖县焦家村发生了一起中等规模的黄土滑坡,滑坡严重影响其下方309国道线和六盘峡水库的安全。采用对裂缝分布、水文地质的调查,结合低空摄影测量、精细工程地质测绘、室内三轴试验等研究方法,对焦家4号滑坡的基本特征进行了分析,对形成滑坡的成灾机理有了初步认识。结果表明:(1)滑坡发生前,后缘裂缝有明显的变形情况;(2)滑坡滑动距离为548.3 m,体积为15.35万m^3,面积为6.6万m^2;(3)饱和黄土应力应变模式表现为强烈的应变软化剪缩型,并具有一定的静态液化特性;(4)滑坡是饱和黄土层静态液化引起的。Since the 1960s , a large number of irrigation systems have been constructed to solve the agricultural drought prob-lems in the loess area. At the same time, the irrigation has induced a lot of loess landslides. At 20 ：00 on January 28 , 2015 , a medium - sized loess landslide occurred in Jiaojia Village, Heifangtai table - land, Yongjing County, Gansu Province, northwest-ern China. The landslide seriously affected the safety of No. 309 national road and Liupanxia Reservoir that were below Jiaojia No. 4 landslide. Based on the investigation of fracture distribution and hydrogeology, combined with research techniques such as low - altitude photogrammetry, high - accuracy engineering geological mapping and triaxial test, the basic characteristics of Jiao-jia No. 4 landslide were analyzed, and the formation mechanism of the landslide was preliminarily understood. The preliminary results showed that：①Before the occurrence of the landslide, there are obvious deformations of trailing - edge fractures ;②The sliding distance of the loess landslide is 548. 3m,the sliding volume is 15. 35 × 10^4 m3 and the sliding area is 6. 6 × 10^4 m2 ; （3）The stress - strain mode of saturated loess is characterized as strong strain softening and shear shrinkage, as well as a certain of static liquefaction; （J） The landslide is caused by static liquefaction of saturated loess layers.

关 键 词：超孔隙水压力 黄土滑坡 焦家4号滑坡 静态液化 

分 类 号：P642[天文地球—工程地质学]