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[HDS07-03] Observation of the pore water pressure response to strong ground motion in a filled slope in Yokohama city
Keywords:pore water pressure, strong ground motion, filled slope
To grasp how an earthquake-induced landslide in a filled slope occur, it is important to understand pore water pressure response to strong ground motion. For this purpose, we settled a seismic and groundwater pressure observation system in a filled slope in Yokohama city, Kanagawa prefecture. The ground motion and groundwater pressure data were collected with the sampling frequency of 100 Hz, using a short-period velocimeter of KVS-300 manufactured by Kinkei System Co. Ltd. and a water pressure sensor of JW-7300 by Sensez Co. Ltd., respectively. The seismometer was placed on the ground, while the water pressure sensor was installed within the fill at depth of 1.6 m. The observation was started on Jul. 1, 2016 and continued to the present. During this period, excess pore water pressure was recognized in accompany with the strong ground motion from seven earthquakes. The durations for the pore water pressure increase in response to strong ground motion were 70-230 s, which were much larger than those observed in another filled slope in Meguro ward, Tokyo prefecture (Doi and Kamai, 2020). Also, the amounts of the pore water pressure increase were larger in Yokohama filled slope. We suggested that the difference of the materials which consist of the filled slopes and/or the topography before the development were possible reasons for the difference of pore water pressure response.