An improved method of Newmark analysis for mapping hazards of coseismic landslides.

Coseismic landslides have been responsible for destroyed buildings and structures, dislocated roads and bridges, cut off of pipelines and lifelines, and tens of thousands of deaths. Accurately mapping the hazards of coseismic landslides is an important and challenge work. Newmark's method is widely applied to assess the permanent displacement along a potential slide surface to determine the coseismic responses of the slope. This paper considers the roughness and size effect of the potential slide surface-unloading joint, and then presents an improved method of Newmark analysis for mapping hazard of coseismic landslides. The improved method is verified using data from a case study of the 2014 M_w 6.1 (USGS) Ludian earthquake in Yunnan Province, China. The permanent displacement yielded from this method range from 0 to 122 cm. Comparisons are made between the predicted displacements and a comprehensive inventory of landslides triggered by the Ludian earthquake to map the spatial variability using certainty factor model (CFM). Confidence levels of coseismic landslides indicated by certainty factors range from -1 to 0.95. A coseismic landslide hazard map is then produced based on the spatial distribution of the values of certainty factors. Area under the curve analysis is used to draw a comparison between the improved and conventional method of Newmark analysis, revealing the improved performance of the method presented in this paper. Such method can be applied to predict the hazard zone of the region and provide guidelines for making decisions regarding infrastructure development and post-earthquake reconstruction. [ABSTRACT FROM AUTHOR]