[1]WANG Qiang,SHAO Shengjun,WANG Jun,et al.Review on Disaster Characteristics of the Seismic Subsidence of Loess Site and its Formation Causes[J].Journal of Seismological Research,2016,39(04):692-702.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
39
Number of periods:
2016 04
Page number:
692-702
Column:
Public date:
2016-10-30
- Title:
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Review on Disaster Characteristics of the Seismic Subsidence of Loess Site and its Formation Causes
- Author(s):
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WANG Qiang1; 2; SHAO Shengjun2; WANG Jun1; ZHANG Zhenzhong1
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(1.Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China)(2.Institute of Geotechnical Engineering,Xi'an University of Technology,Xi'an 710048,Shaanxi,China)
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- Keywords:
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earthquake disaster of site; seismic subsidence of loess; historical earthquake; physical indexes; critical dynamic stress
- CLC:
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P315.9
- DOI:
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- Abstract:
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Based on many historical materials and scientific investigations,we studied the seismic subsidence damages of loess induced by several moderately strong and strong earthquakes at loess area,and analyzed the damage types,developing characteristics and formation conditions of the loess seismic subsidence disaster.Then according to a large amount of dynamic triaxial test results on different regional loess,we comparatively investigated the variation laws of regional physical indexes,which meet the occurrence conditions of seismic subsidence of loess,furthermore,we researched several influencing factors of critical dynamic stress and presented variation laws between them.It can be concluded from this study that the loess subsidence cases of loess which were occurred at meizoseimal area of several moderately strong and strong earthquakes are confirmed.The mode of the seismic subsidence damage of loess can be classified into vibrated-compact seismic subsidence,seismic-subsidence landslide,and liquefaction seismic subsidence,whose formation are determined by the physical conditions of soil,terrains and landforms,and earthquake motion.The loess at loess plateau should take account of the seismic subsidence of loess under all water content levels once void ratio is larger than 0.8,while for loess distributed at Henan,Hebei and southeastern Shanxi provinces,the seismic subsidence of loess can be judged by shrinkage limit.The critical dynamic stress is mainly dependent on the structural strength,and critical dynamic stress ratio can be well expressed with the power function of water content.