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Extensive infrastructure collapse resulted from the cataclysmic earthquake
that struck off the eastern coast of Japan on 11 March 2011 and from its
consequent gigantic tsunami, affecting not only the Tohoku region but also
the Kanto region. Among the geological and geotechnical processes observed,
land subsidence occurring in both coastal and inlan...
Contexts in source publication
Context 1
... of post-earthquake settlement as shown in Fig. 1 originated from the superimposition of land subsi- dence before the earthquake and consolidation settlement caused by the dissipation of excess pore pressure generated during the earthquake. Figure 2 depicts an example of variations of settlement over time before and after the Tohoku Earthquake in 2011. The tendency presented in Fig. 2 is almost identical as that presented previously in Fig. 1. ...
Context 2
... shown in Fig. 1 originated from the superimposition of land subsi- dence before the earthquake and consolidation settlement caused by the dissipation of excess pore pressure generated during the earthquake. Figure 2 depicts an example of variations of settlement over time before and after the Tohoku Earthquake in 2011. The tendency presented in Fig. 2 is almost identical as that presented previously in Fig. 1. Kazama (2014) reported that post-earthquake settlement of clay deposits are caused by collapse of clay soil particle structures immediately after the earthquake and the recov- ery of collapsed structures to the new state of clay structures This mechanism for post-earthquake ...
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Soil liquefaction is one of the major geohazards triggered by an earthquake. It can cause lateral spreading, ground settlement, sand boiling, which in turn, may damage buildings and infrastructure and result in loss of life. While many case histories of soil liquefaction have been reported after recent major earthquakes, few focused on detailed stu...
Citations
... This could have a negative impact on the model's predictive performance in predicting long-term subsidence. The possibility that strong seismic activity from the Tohoku Earthquake affected the secondary consolidation of the Holocene has been noted by several studies (Imakiire and Koarai 2012;Yasuhara and Kazama 2015;Noda et al. 2017). Model A is likely to have been affected by the Tohoku Earthquake, and seismic effects on land subsidence modeling require further investigation. ...
The causes of land subsidence in Kawajima, Japan, have been investigated through data compilation and numerical modeling. Land subsidence has progressed despite a gradual increase in the hydraulic head in the long term. Taking into account the temporal changes and depth distribution of groundwater abstractions, the contraction of formations, and the complexity of the hydrogeological structures, it is proposed that agricultural groundwater use is one of the main triggers for land subsidence. A one-dimensional numerical simulator for coupled groundwater flow and soil deformation was developed with an evolutionary algorithm for model calibration. The calculated spatiotemporal changes in the past-maximum effective stress showed that plastic consolidation in the clayey layers progressed part by part every summer season resulting in long-term and gradual land subsidence under the same range of groundwater level fluctuations. The results also showed that the plastic deformation occurred in both the Holocene and Pleistocene sediments in the drought years, leading to significant subsidence. The model’s predictive performance showed good potential except for a structural prediction error after the Tohoku Earthquake in 2011. The scenario analysis indicated that management of the groundwater level in summer is one of the effective countermeasures in suppressing land subsidence caused by seasonal groundwater level fluctuations. These methodologies and findings can be used for groundwater management in similar cases around the world. Additional investigation is necessary on the influence of large earthquakes in deformation conditions in order to further improve the developed model.
... (2) Example of the effects of the Great East Japan Earthquake Yasuhara and Kazama 15) described the long-term Long-term settlement of the clay stratum due to earthquake 15) . ...
... (2) Example of the effects of the Great East Japan Earthquake Yasuhara and Kazama 15) described the long-term Long-term settlement of the clay stratum due to earthquake 15) . ...
The 2011 Great East Japan Earthquake caused massive ground damage, including liquefaction of sandy grounds, collapse of river levees and lands developed for housing, etc., particularly in regions across eastern Japan. Not only damage to “currently unqualified” structures that did not conform to existing design standards and codes but also ground damage that could not be explained within the framework of conventional geomechanics and geotechnical engineering was observed. Particularly in the latter case, therefore, it has become necessary to develop new techniques in geomechanics without being restrained by the conventional framework. From the above standpoint, this paper reviews the research that has been carried out in the field of geotechnology after the Great East Japan Earthquake. More specifically, new knowledge relating to the mechanism of liquefaction damage at Urayasu City and other ground deformation caused by the earthquake is introduced, together with the results of research carried out on ground strengthening techniques.
