Abstract:

The loess plateau covers a vast area in China and is suffered from frequent geological hazards. Multiple rotational loess landslide is a special type of geological hazards owing to its basic characteristics and complicated causes. On the basis of field investigation and engineering geological survey, basic characteristics of landslides in Weibei loess tableland edge and Heifangtai loess tableland edge are analyzed. The formation of large loess-red mudstone multiple rotational landslides in Weibei tableland that is mainly affected by neotectonic movement, river lateral erosion and lithology, while multiple rotational shallow loess landslides and loess-red mudstone landslides in Heifangtai tableland are the result of a long-term excessive irrigation. Three formation and evolution modes of multiple rotational loess landslides are first built which are extensional rotational landslide, gradually extinct rotational landslide, compound rotational landslide. Examples of respective modes are introduced and analyzed. Furthermore, failure mechanism of multiple rotational loess landslides is put forward. The whole deformation process of multiple rotational loess landslides includes five phases, namely, regional creep and squeeze, accelerated sliding, temporary self-stabilizing, new landslide initializing in crown, self-stabilizing. All these works build a foundation for stability evaluation of multiple rotational loess landslides.

Key words: multiple rotational loess landslide, deformation characteristics, failure mode, landslide