FUNDAMENTAL RESEARCH ON LIQUEFACTION COUNTERMESURES FOR DOUBLE STEEL SHEET PILE QUAY WALLS USING PERMEABLE SANDBAGS

Abstract

 The 2011 off the Pacific coast of Tohoku Earthquake has prompted the development of earthquake-resistant port facilities. Port facilities not only mitigate damage in the event of a disaster, but also provide a base for reconstruction work and an economic base for the fishing industry, and thus require rapid and rational maintenance. The authors focused on the liquefaction of soil filled with double steel sheet pile quay walls, and verified countermeasures using sandbags filled with highly permeable gravel and permeable steel sheet piles to reduce excess pore water pressure in the ground through centrifuge model experiments. The experimental results showed that the drainage effect of the sandbags suppressed the generation of excess pore water pressure, and that the permeable steel sheet piles shortened the dissipation time of the excess pore water pressure. The replacement of the liquefied layer with sandbags was also found to deter sheet pile deformation by increasing the ground bearing capacity behind the sheet piles.