Abstract: The topography, occurrence mechanism and lithology are the important factors of landslide movement. The lithology, seismic intensity, geological structure and topography in the travel path of 215 incomplete obstruction landslides with volumes more than 10⁴m³ induced by Wenchuan earthquake were studied. Based on the classification of the factors established, we studied the factors influencing the movement distance of incomplete obstruction landslides. The following results are drawn. In the influence factors of topography in the travel path, the distance is largest in the straight valley topography, followed by the concave, ladder, turning valley, slope toe-type and slope-type landslides, in turn. The topography not only has remarkable influence on the distance of large-scale landslides, but also on the medium and small-scale landslides as well, which is the most important factor influencing the distance. The formation mechanism controlled by lithology, seismic intensity and geological structure has little influence on the mobility of medium-and small-scale landslides. For the large-scale landslides with volume more than 10⁶m³, the distance of landslide with medium hard rock is larger than landslides with hard and soft rock. In the seismic intensity Ⅸ to Ⅺ areas, the landslide distance decreases with intensity increasing, contrary to the distribution of landslide-point density and landslide-area density. The geological structure has influence on the slide aspect of landslides and occurrence mechanism, but the influence is not remarkable to the landslide movement distance.

Key words: incomplete obstruction seismic landslide, movement distance, influence factor, mechanism

摘要： 地形条件、启动机制和岩性条件是滑坡运动的主要影响因素。通过分析汶川地震诱发的215处体积>1×10⁴m³的未完全受阻滑坡的运动场地地形条件、岩性、地震烈度、岩层倾向与坡向的关系，建立各影响因素的分类指标，分析各影响因素对滑坡运动距离的影响及作用机制。研究结果表明：场地地形条件不仅显著地影响了大型滑坡的运动距离，而对中小型滑坡同样有效，是同等规模下滑坡运动距离产生差异的最主要影响因素。运动场地地形条件中沟谷顺直型滑坡的运动距离最大，随后依次为凹面型、阶梯型、沟谷偏转型、坡脚堆积型和坡面堆积型，由岩性、地震烈度和岩层倾向与坡向关系确定的滑坡成因模式或启动机制对中小型规模的滑坡运动距离影响不显著。对于体积>1×10⁶m³的大型滑坡，同等规模下中等硬度岩性的运动距离大于坚硬岩体和软岩；在Ⅸ-Ⅺ度地震烈度区，与滑坡点密度和面积密度的分布规律相反，滑坡运动距离随烈度的增加而减小；坡体结构虽然影响了滑坡发育的分布规律和成因模式，但对滑坡运动距离的作用却不显著。

关键词: 未完全受阻滑坡, 运动距离, 影响因素, 作用机制