2015/9/22 2)Unfavorableto ()Hazardous to earqake resistance: 20152 Yiliang Earthquake: 201522 20152 2.2.2 Construction site categories 1.Seismic inluence of construction site 2 2015/9/22 2 (2) Unfavorable to earthquake resistance: • Soft soil; • liquefiable soil; • stripe-shaped protruding ridge; • high isolated hill; • non-rocky steep slope; • river banks and edges of slopes; • soil strata having obviously heterogeneous distribution in plane (such as abandoned and filled river beds, fracture zone of fault, and hidden swamp(沼泽地), creek（溪）, gully（沟） and pit（矿井）, as well as subsoil with partial excavation and filling. 2015/9/22 熊海贝，同济大学土木工程学院 xionghaibei@tongji.edu.cn 7 (3) Hazardous to earthquake resistance: Places where landslide, avalanche, subsidence, formation of cracks and debris flow (mud-rock flow) are liable to occur during an earthquake,orthe location of active fault. Beichuan, Sichuan Province Landside 2015/9/22 熊海贝，同济大学土木工程学院 xionghaibei@tongji.edu.cn 8 (3) Hazardous to earthquake resistance: Places where landslide and the location of active fault. 2015/9/22 熊海贝，同济大学土木工程学院 xionghaibei@tongji.edu.cn 9 Yiliang Earthquake: Landslide: The quakes caused landslides that blocked roads in the area of the hardest hit region, the town of Luozehe (洛泽河) in Yunnan Province. The affected areas are densely populated and mountainous. Power and Communication stopped: cutting off highways and communications, as well as power supply Lost and Losses: 81 people killed, 800 people injured, and more than 6,600 houses were flattened, while many thousands more were damaged. In Guizhou Province, collapsed houses were reported in Weining County, and houses were damaged in Hezhang County. Direct economic losses were estimated at 3.5 billion yuan . 2015/9/22 熊海贝，同济大学土木工程学院 xionghaibei@tongji.edu.cn 10 • Structures that lie atop the surface trace of an active fault can be damaged or destroyed by “surface fault rupture” during an earthquake.( Fig 2.1) Fig. 2.1 Crop rows offset by a lateral strike- slip fault shifting in the 1976 Earthquake that shook El Progresso, Guatemala. • A structure that lies partially or entirely w ithin an Earthquake Fault Zone may be subject to requirements for site-specific geologic studies before any new or additional construction may take place. ( Fig.2.2 ) Fig. 2.2 Railroad tracks shifted by the 1976 Guatemala Earthquake 2015/9/22 熊海贝，同济大学土木工程学院 xionghaibei@tongji.edu.cn 11 2.2.2 Construction site categories 1. Seismic influence of construction site Local site condition Play an important role Responses of structures Q: How the performance of a High￾rise buildings founded on deep soft soils compare with the one on rock? Why? A: Earthquake records on soft to medium clay sites indicate that the soil amplification factors for long-period spectral accelerations can be significantly large. WHY ? HOW ？ 2015/9/22 熊海贝，同济大学土木工程学院 xionghaibei@tongji.edu.cn 12