The M s 8.0 Wenchuan earthquake occurred along the Longmenshan Faults in China and was a great disaster. Most of the damage and casualties during the quake were concentrated along surface rupture zones: the 240-km-long Beichuan-Yingxiu Fault and the 70-km-long Jiangyou-Guanxian Fault. Although the Longmenshan Faults are well known and studied, the surface Fault ruptures were not considered in mitigation planning, and the associated ground-motion hazard was therefore underestimated. Not considering Fault rupture and underestimating ground-motion hazard contributed to the disastrous effects of the earthquake. The lesson from the Wenchuan earthquake disaster is that the fault rupture hazard must be assessed and considered in mitigation. Furthermore, the deterministic approach is more appropriate for fault rupture hazard assessment than the probabilistic approach. 1. Introduction On May 12, 2008, the Ms 8.0 Wenchuan earthquake in China caused many houses to collapse and huge casualties. It occurred in the Longmenshan thrust nappe tectonic zone, the junction of the Bayan Har block on the Tibetan Plateau and the South China block in eastern China (Figure 1). The zone consisted of a front range fault (Jiangyou-Guanxian Fault)， a central fault (Beichuan-Yingxiu Fault), a back range fault (Wenchuan-Maoxian Fault), and their related folds (Figure 1). The zone has experienced strong tectonic activity and intensively active faults, making it a strong earthquake-prone area since it is not only the junction of the Bayan Har and South China blocks, but also a part of the north-south seismic tectonic zones on the Chinese mainland. The MS 8.0 Wenchuan earthquake was the result of the Longmenshan thrust nappe pushing southeast, accompanied by clockwise shearing. Figure 1: Seismotectonics and distribution of historical earthquakes of the Wenchuan area. (1) Holocene active fault. (2) Late Pleistocene active fault. (3) Early and middle Pleistocene active fault. (4) Buried active fault. (5) Normal fault. (6) Strike-slip fault. (7) Ms 8.0 earthquake surface ruptures. (8) Epicenter of the Ms 8.0 earthquake. (9) Historical earthquakes ranging from M s 4.7 to 5.0. (10) Historical earthquakes ranging from M s 4.7 to 5.0. (11) Figure location. The Wenchuan earthquake was a great disaster, causing more than $110 billion in damage and killing about 90,000 people [1]. There were many reasons for this disaster, such as large magnitude (Ms 8.0), high mountains and steep slopes, and dense population. However, one of the main reasons was that the seismic hazards, surface fault rupture,
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