A STUDY ON ESTIMATION OF STREET-BLOCKADES CAUSED BY A GREAT EARTHQUAKE

摘要

In order to mitigate secondary disasters to a community, the purpose of this of this study is to develop a method for evaluating urban improvement policies for disaster prevention by observing intersections to which all streets connected are blocked by collapsed buildings caused by a great earthquake. A model for estimating the probability of streets being blocked and inaccessible to vehicles is built on the basis of the data of Higashi-Nada Ward in Kobe City, which suffered a great deal of damage from the Great Hanshin-Awaji Earthquake Disaster. A method for forecasting the rate of occurrence of these intersections is then proposed. Based on the simulation results through the forecasting method, the effectiveness of two types of policies is evaluated, that is, reinforcing and earthquake-proofing deteriorated wooden houses, and widening of narrow roadways.