INFLUENCE OF THE UNDERGROUND WATER FLOW IN THE RE-DEPOSITION PROCESS OF A GROUND AFTER LIQUEFACTION

Abstract

 Liquefaction damage was often observed at the sites where liquefaction was occurred before. It maybe related to the site specific characteristics, and we assume the underground water flow at these sites made the loose deposition of the ground to make the multiple occurrence of liquefaction. In order to examine the above-mentioned assumption, we made the device which could simulate a flow of the underground water. And we measured the density of deposited ground with and without water flow. As a result, after giving vibrations to liquefy, the density increase of the re-deposited sand after liquefaction with the water flow was smaller than that of the case without a water flow. It means that the soil density was not increased a lot after liquefaction in the case when groundwater flow exists. Thus, there could be a case that the ground with the underground water flow can be easily re-liquefied than the ground without the underground water flow.