中文摘要：

古遗址赋存于岩土体之中，是岩土体的一部分，故尝试采用岩土工程分析手段对其破坏机制进行研究。在“5．12”汶川地震中，重庆合川钓鱼城古战场遗址的始关门出现了局部开裂、错位等变形破坏现象。地质勘察表明，始关门赋存于滑坡、裂隙等复杂地质环境中，故抽取了始关门的地质模型，采用有限差分软件FLA^3D对其进行了三维地震动力响应模拟，分析其变形破坏机制。结果表明，始关门应力集中明显，并在地震波作用下有明显位移出现。始关门破坏是各种地质因素综合作用的结果。“5．12”汶川地震是诱导因素，滑坡、陡崖裂隙等地质结构是主要原因，古城门自身强度减小是发生破坏的内因。模拟结果为始关门修复设计提供了可靠的科学根据，具有一定的研究意义和推广价值。

英文摘要：

The ancient ruins, Shiguan gate attached to rock and soil mass, is a part of rock and soil mass; so geotechnical analysis is used to study of its damage mechanism. In the ＂5.12＂ Wenchuan earthquake, local cracking and dislocation phenomena occurred in Shiguan gate of Diaoyucheng ancient battlefield ruins in Hechuan of Chongqing. Geological survey shows that the Shiguan gate is under complicated geological conditions like landslides, cracks etc., so geological model of Shiguan gate is sampled and the fast Lagrangian analysis of continua in 3D （FLAC3~） is used to make 3D simulation of the seismic dynamic response and analyze damage mechanism of Shiguan gate. Simulation results show that the stress concentration obviously occurs in Shiguan gate and displacements appear obviously under the conditions of seismic waves. The damage of Shiguan gate results from various geological factors. ＂5.12＂ Wenchuan earthquake is induced factor, geological structure like landslides, cracks etc., is the main reason; the reduction of its own intensity is the internal reason. The reliable scientific basis of repair and design of Shiguan gate is provided by the the simulation results. It has certain study significance and promotion value.