New project to prevent liquefaction-induced damage in a wide existing residential area by lowering the ground water table. Issue 91 (December 2016)

• Record Type: Journal Article
• Authors: Yasuda, Susumu; Hashimoto, Takao
• Is Part Of: Soil dynamics and earthquake engineering. Issue 91(2016:Dec.)
• Page Start: 246
• Page End: 259
• Publication Date: 2016-12
• Subjects: Liquefaction -- Countermeasure -- Residential area -- Ground water table; Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2016.09.029
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: In residential areas where liquefaction occurred during the 2011 Great East Japan Earthquake, houses, roads, water pipes, sewage pipes and gas pipes were damaged, interrupting daily life. Though settled and tilted houses were repaired by uplifting, the ground in the whole area, including around lifelines and roads, must be treated by special measures to prevent liquefaction-induced damage. A project to improve the liquefiable soil of an entire area by lowering the ground water table started in November 2011. Based on case studies at sites of damaged and undamaged houses, a water table of about GL-3m was judged to be appropriate to prevent damage due to liquefaction. In-situ tests clarified that the pore water pressure decreased due to dewatering only at shallow depths and that subsidence was small. Highlights: About 27, 000 houses were damaged due to liquefaction by the Great East Japan Earthquake. A project to improve the liquefiable soil of an entire area by lowering water table started. A water table of about GL-3m was judged to be appropriate to prevent damage of houses. In-situ tests conducted in several cities clarified that subsidence due to lowering was small. Drain pipes placed under roads can lower the water level under houses also.