Abstract:

A large bedded landslide occurred in Sunjia Town, Wanzhou District of Chongqing. There were multiple disintegration modes in the sliding process. In order to study the slip model of such bedded rock landslide, the slip structure and ground rupture were investigated. Furthermore on this basis, the landslide was partitioned and the sliding distance, movement patterns and building’s vulnerability were analysed. Results reveal that 1) potentially unstable slopes were made free by slope cutting of the leading edge of the quarry, and the anti-sliding force decreased, which triggered the sliding of shallow bedded weak shale in the middle and weathered contact zone in the back; 2) the primary slip body slid about 29.5m, the main slide direction was 5° and the thickness of slip body was about 15m; 3) affected by the change of weathered layer thickness and the previous topographical conditions, the partitioned disintegration was obvious after the sliding. The intensity of each partition’s effect on building’s vulnerability can be ranged as: front accumulation zone (Ⅵ) > groove damaging zone in the back edge (Ⅱ) > central nappe zone (Ⅳ), crushing zone (Ⅶ) > local block sliding zone (Ⅴ) > central thrust zone (Ⅳ) > integral sliding zone (Ⅲ₁, Ⅲ₂ )> affected zone in the back edge (Ⅰ). Moreover, the zoning map of landslide’s crushing and disintegration is given, and it has reference value for analyzing landslide risk distribution.

Key words: bedded rock landslide, sliding distance, movement pattern, disintegration, intensity of effect