Characteristics of Flow Failures Triggered by Recent Earthquakes in China

Abstract

In recent years, several strong earthquakes occurred in China, like the 2008 Wenchuan Earthquake, 2003 Bachu Earthquake, etc. These earthquakes triggered numerous flow failures, causing severe damage to buildings and infrastructure. In this paper, some general characteristics of flow failures triggered by these recent earthquakes are reviewed. Based on seismic data analysis and field investigation, a brief overview of typical liquefaction phenomena and their characteristics during recent large earthquakes in China is presented. It is manifested that liquefaction occurs mainly in the alluvial plain sediments with low groundwater levels. Some new phenomena, like liquefaction of gravelly soil and deep-level sandy soils, and re-liquefaction, should be paid enough attention in further study. Then, the paper outlines the spatial distribution characteristics of flowslides induced by earthquakes to provide a reference for seismic design and risk mitigation. The flowslide-prone areas are dip slopes opposing the propagation direction of seismic wave, which are mostly located along the surface rupture and near the epicenter, especially on the hanging wall of the fault. Lastly, the state of the post-earthquake investigation and evaluation method for flow failures in China is presented briefly. Field investigation and remote-sensing image interpretation play important roles in the data collection and evaluation of seismic geohazards after earthquakes.