【摘要】 探讨中陡倾角顺层岩质斜坡发生倾倒变形的特征、发育条件及形成机制。白龙江干流受区域构造环境条件的影响,纵向河谷发育,河谷两岸志留系白龙江群的砂质板岩、千枚岩等较发育,尤其在甘肃的舟曲、武都一带以软质、薄层状的绢英、碳质千枚岩为主。这些干流段岸坡稳定性较差,尤其是顺层岸坡段滑坡较发育,且多以滑移-弯曲(溃曲)、滑移-拉裂模式为特征。通过对白龙江干流水泊峡水电站的Ⅶ#滑坡、碧口水电站库区的青崖岭滑坡与孟家干沟滑坡的现场调查、分析,揭示了在陡顺倾层状岩质斜坡中还发育一种特殊的倾倒变形破坏模式,即滑移-倾倒模式。该类变形多发育在临空条件好、坡度40°以上由软硬相间或软硬互层状、岩层倾角一般在65°以上的高陡层状岩质斜坡中,是在斜坡应力场或遭受水、地震等作用下,坡脚首先发生初始倾倒变形,同时上部岩体发生滑移-倾倒,最终岩层发生连续弯曲变形、根部折断,折断面贯通而形成滑坡。更多还原

【Abstract】 This paper researches on the characteristics the formation conditions and mechanism of the toppling deformation occurring on the medium-steep bedding rock slopes.The longitudinal valley is well developed along the Bailong River trunk streams influenced by regional geotectonic conditions.The Silurian sandy slate and phyllite are well developed in this area,especially the soft thin-layered sericite quartz and carbonaceous phyllite exposed in Zhouqu and Wudu regions.They leading to the lower stability of bank slopes.Particularly,the landslides are more likely to occur in the bedding slopes as the failure modes of sliding-toppling and sliding-tension.Further,a special toppling failure mode is founded on the steep bedding rock slopes,namely,the termed sliding-toppling mode,based on the field investigations associated withⅦ#landslide situated in the Shuiboxia hydropower station,the Qingyaling landslide and the Mengjiagangou landslide situated in the Bikou hydroelectric power station on the Bailong River.It can be concluded that the sliding-toppling mode is primarily well developed on the steep bedding rock slopes with alternating soft and hard layers.These rock slopes generally have a favorable free surface condition with the angle of slope greater than 40°and the strata dip angle greater than 65°.The formation mechanism is induced by the slope stress field,water or earthquake.The initial deformation occurs at the lower part of the slope,along with the slidingtoppling at the upper part.Finally,the continuous toppling failure surface appears in the basal plane and results in the landslide.更多还原