中文摘要：

远离震中的汉源县老县城在汶川大地震中遭到了严重震害,是Ⅵ度区内的唯一的Ⅷ度烈度异常区。汉源的地震烈度异常现象引起学术界的广泛关注。在汉源科学考察基础上,介绍了汉源震害情况,收集和整理了汉源县城及附近有关工程场地的强震和土体力学参数资料。通过背后山滑坡体有限元分析结果与汉源附近强震台记录的比较,从传递函数角度分析了背后山滑坡复活对烈度异常的影响,研究了汉源特殊土层结构对地震动的影响。结果表明,背后山滑坡的复活和特殊土层结构的放大作用等场地条件的影响是引起烈度异常的主要原因。所得结论对进一步分析汉源烈度异常的原因具有一定的参考价值。

英文摘要：

The old Hanyuan county town far away from the epicenter suffered serious damage during Wenchuan earthquake.It is the only abnormal intensity Ⅷ region in intensity Ⅵ region.The abnormality of seismic intensity in Hanyuan attracted attention by the academic circles.Based on the Hanyuan seismic investigation,the damage situation was introduced,and the data on strong ground motion and soil mechanic parameters in and near Hanyuan county were collected.Beihou Mountain landslide revival affecting abnormal intensity was analyzed from viewpoint of transfer function by comparing the FEM results of Beihou Moutain and the strong motion records.The special soil layer structure affecting ground motion was also studied.The results show that site conditions,such as Beihou Mountain landslide revival and special soil layer structure amplification effect,are the main reasons leading to abnormality of seismic intensity.