CREATION OF A NEW LIQUEFACTION HAZARD MAP REFLECTING RELATIONSHIP BETWEEN LIQUEFACTION POTENTIAL AND LIQUEFACTION-INDUCED ROAD SUBSIDENCE

Abstract

 The aim of this study is first to investigate the relationship between liquefaction potential and liquefaction-induced road subsidence that occurred in Urayasu City in the 2011 off the Pacific Coast of Tohoku Earthquake, and then to develop a new hazard map reflecting this relationship, which provides expected liquefaction-induced road subsidence. The liquefaction potential distribution in Urayasu City during the particular seismic event of this 2011 earthquake was evaluated with an available geotechnical data set and the values of liquefaction-induced road subsidence at 251 locations were obtained from a set of the Digital Surface Models (DSMs) from airborne LiDAR surveys before (2006) and after (2011) the 2011 earthquake. Estimated liquefaction potential values and corresponding values of liquefaction-induced road subsidence show that the subsidence values are larger in general for residential roads than those for the main roads given the same value of liquefaction potential. The obtained relationship between values of liquefaction potential and road subsidence are reflected upon a newly developed liquefaction hazard map for Urayasu City.