2014 年 2 巻 1 号 p. 144-158
This paper introduces a liquefaction mitigation method that uses log piles as environmentally friendly and practical solution for strengthening civil engineering structures. The liquefaction mitigation measure explored in this paper can be used to increase the earthquake resistance of loose sands by improving the density of soil. During the Tohoku Pacific earthquake in 2011, liquefaction was pervasive in large portions of the region, especially in Tokyo Bay and the city of Urayasu. Extensive liquefaction caused extensive damage to residential properties, electricity, water, sewage networks, and bridges. The mitigation of global warming is an important issue that requires immediate attention. Because the use of wood can be effective for preventing global warming, the authors have considered it to mitigate liquefaction damage. A series of large-scale shaking table tests was performed to investigate the effect of liquefaction mitigation by log piling into sandy ground. The results indicate that the method of log piling is an effective liquefaction mitigation compared with methods for increasing density, such as the densification method. Portable dynamic cone penetration (PDCP), Swedish weight sounding (SWS), automatic ram sounding (ARS), piezo drive cone (PDC), and flat dilatometer (FDM) tests, as well as field tests, were performed in the city of Urayasu. These tests were performed to confirm the effectiveness of log piling on liquefaction mitigation.