【摘要】 在野外地震地质科学考察的基础上,围绕汶川地震发震断层的特征、发震机制、地表破裂带的分段性与分带性、南北构造带地震危险性、地震地质灾害的多发性及链生性、工程建(构)筑物的破坏特征与安全性、地震烈度区划问题及极端自然灾害的预测与应对等进行了分析和讨论,并就有关问题提出了一些新的思考。结果表明,低速滑动断层、晚更新世断层或中央活动断裂也可以发生强震;汶川地震同时具有深部构造的控震作用;地表破裂沿走向可分为映秀—安县段、北川—关口段及青川段;地表破裂可分为主破裂、牵动破裂与感应破裂3种类型;青川段的深部破裂与浅部破裂没有几何上的连续关系或继承关系;贺兰—川滇南北构造带是中国大陆强震多发带,尤其是其北段的六盘山—天水—武都—青川一带未来的强震危险性不容忽视;汶川地震地质灾害具有灾害类型多、成因机理复杂、灾害链长、规模大、范围广、灾害程度深、危害对象广、持续时间长等特点;高烈度区和活断层沿线的地质灾害危险性区划与预测评价对防灾减灾极为重要;活动断裂沿线应注意破裂影响带宽度与建筑物安全避让距离;应对地震等极端自然灾害,应以预防为主,综合减灾;地震烈度区划应同时考虑活动断层的复发周期、地震的离逝时间乃至地形地貌条件;重大工程应提高设防烈度;应当加强极端自然灾害预测评估,完善应对对策和提高应对水平。更多还原

【Abstract】 On 12 May 2008,a magnitude 8.0 earthquake occurred in the Longmen Mountain fault zone of the western Sichuan basin.On the base of seismogeological investigation,the major issues included triggering mechanics,fracture characteristics,hazard assessment,seismic-induced landslide characteristics,damage characteristics of construction,tectonic stability analysis of mainland China,and mitigative measures of earthquake hazards for Wenchuan earthquake were analyzed and discussed.The results show that low-activity fault and fault of Late Pleistocene would trigger strong earthquake and ground rupture were triggered by spontaneity,shear traction and dynamic wave transmission.Moreover,there were weak interrelationship between deep rupture and shallow rupture in Qingchuan County,and there would be high earthquake risk in the north of Helan-Chuandian SN tectonic zone.Finally,because of the complexity and destructiveness of Wenchuan earthquake,the earthquake risk assessment and useful mitigative measures were very important for metropolitan and mountain area.It can help us to prevent earthquake hazards and reduce the loss of earthquake disaster.更多还原