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The 2008 Wenchuan earthquake with M w 7.9 occurred at Yingxiu County in Longmenshan thrust fault belt, southwest China, having triggered a huge amount of slope failures. This paper applied a detailed inventory with more than 190,000 slope failures and strong ground motion records of 187 seismic stations to analyze the qualitative and quantitative relations between slope failure distribution and seismic parameters. The results revealed that slope failure distribution was exponentially decreased with the increment of epicentral distance and distance from surface fault rupture; peak ground acceleration (PGA) on the hanging wall side was apparently larger than that on footwall side. Linear correlation between concentration of slope failures (LNC) and the percentage of the area affected by slope failure (LAP) and PGA was demonstrated by statistical analysis, which revealed that 0.18~0.21 g horizontal PGA was the threshold value of the occurrence of slope failure. Furthermore, this paper presented an empirical model for the attenuation relation of slope failure distribution. [ABSTRACT FROM AUTHOR]

Abstract: The 2008 Wenchuan earthquake with a surface wave magnitude of 8.0 triggered numerous landslides along the Longmenshan thrust fault belt in Sichuan province of China. The authors investigated various influential factors on the slope stability of 119 landslides in Wenchuan County, such as the horizontal peak ground acceleration, slope angle, slope height, rock type and geological structure. We separately developed acceleration attenuation laws for both the hanging wall and footwall side from 183 seismic stations. These formulae confirmed the hanging-foot wall effect had notable influence on landslide distribution density and occurrence probability. Further, we explored the qualitative tendency of landslide distribution and occurrence probability related with each influential factor. The results from the quantitative analysis by a multivariable method demonstrated that slope height, horizontal peak ground acceleration and geological structure had a stronger effect on the sliding area and volume than slope angle and rock type. [Copyright &y& Elsevier]