（1 西安理工大学土木建筑工程学院， 西安 710048； 2 陕西省建筑科学研究院， 西安 710082）

［摘要］小雁塔是“丝绸之路”世界文化遗产建筑的重要组成部分，为研究该塔动力特性及结构损伤，采用动态测试系统进行了原位动力测试，采集了在地面随机激励下结构振动信号，通过时域及频域分析，得到了小雁塔沿东西方向及南北方向的前3阶频率、振型及振型阻尼比；并通过计算得到结构模态柔度曲率曲线及曲率幅值突变系数曲线，依据柔度曲率幅值突变规律对小雁塔进行了损伤定位识别。结果表明，结构第2层、第8层及第11层发生了较严重的损伤，损伤程度与柔度曲率幅值突变量关系密切，且结构开洞对损伤定位识别的显著性有一定影响。因此，通过进行砖石古塔原位动力测试，依据模态柔度曲率幅值突变规律可实现结构损伤定位，为古塔结构损伤研究提供了参考。

［关键词］砖石古塔； 动力测试； 动力特性； 损伤识别

中图分类号：TU311-3文献标识码：A文章编号：1002-848X(2019)05-0038-06

Study on dynamic characteristics and structural damage identification of Xiaoyan Pagoda

Lu Junlong1, Li Xiaolei1, Tian Penggang2

（1 School of Civil Engineering and Architecture, Xi′an University of Technology, Xi′an 710048, China；2 Institute of Building Science of Shaanxi Provionce, Xi′an 710082, China）

Abstract:As an important part of the World Culture Heritage Buildings named the “Silk Road”, dynamic characteristics and structural damage of Xiaoyan Pagoda were studied. In-situ dynamic tests were carried out and the structural vibration signals were collected under random excitation on the ground using a dynamic testing system. The frequencies, mode shapes and damping ratio of modal  of the Xiaoyan Pagoda for previous three orders along the east-west direction and the north-south direction were obtained after the time-domain and frequency-domain analyses. The flexibility coefficient curve and the abrupt curvature amplitude of the structural modal  were calculated, and then the damage location identification was made according to the sudden change of flexibility curvature amplitude. The results show that the serious damaged was located at the second, eighth and eleventh layers of the structure, and the degree of damage is closely related to the flexibility curvature amplitude mutation, and the structural opening performed a certain influence on the significance of damage location and identification. Therefore, through the in-situ dynamic test of ancient masonry pagoda, structural damage location can be achieved according to the law of abrupt change of modal flexibility curvature amplitude, which provides a reference for damage research of ancient pagoda structure.

Keywords:ancient masonry pagoda; dynamic test; dynamic characteristic; damage identification

*国家自然科学基金资助项目（51778527，51308455），陕西省自然科学基础研究计划资助项目（2018JM5111），陕西省博士后科学基金资助项目（2014）。

作者简介：卢俊龙，博士，副教授，硕士生导师，Email：lujunlong@sohu.com。