CASE STUDY ON RAPID ASSESSMENT OF REGIONAL SEISMIC LANDSLIDE HAZARD BASED ON SIMPLIFIED NEWMARK DISPLACEMENT MODEL: WENCHUAN MS 8.0 EARTHQUAKE

The rapid assessment method on seismic landslide hazard based on simplified Newmark displacement model is preliminarily developed, in Wenchuan Ms 8.0 earthquake severely afflicted 11 counties. With the real-time earthquake ground motion parameters, empirical engineering geology lithology formations, topographic slope data, the module of seismic landslide hazard rapid assessment is produced based on ArcGIS spatial data modeller tools. Static safety factor Fs and critical acceleration ac of regional shallow saturated rock and soil mass slope are calculated, according to which seismic landslide susceptibility is assessed. The Arias intensity of Wenchuan earthquake and regional landslide displacement DN distribution are calculated with empirical formula, based on which rapid assessment of seismic landslide hazard in Wenchuan earthquake severely afflicted area is realized. The assessment results can be reference for emergency response decision-making. It is indicated that tens of catastrophic landslides are almost totally located in extreme high-high hazard zone, which within both sides about 20km of Longmenshan central fault belt through comparing the seismic landslide investigation and assessment results. The comparing result indicates the well reliability of assessing model. Meanwhile, the limitation is also analyzed that local assessment result is inaccurate due to poor spatial data accuracy and update. Some improvement suggestion is provided.