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（1 西安理工大學土木建筑工程學院， 西安 710048； 2 陜西省建筑科學研究院， 西安 710082）
［摘要］小雁塔是“絲綢之路”世界文化遺產(chǎn)建筑的重要組成部分，為研究該塔動力特性及結(jié)構(gòu)損傷，采用動態(tài)測試系統(tǒng)進行了原位動力測試，采集了在地面隨機激勵下結(jié)構(gòu)振動信號，通過時域及頻域分析，得到了小雁塔沿東西方向及南北方向的前3階頻率、振型及振型阻尼比；并通過計算得到結(jié)構(gòu)模態(tài)柔度曲率曲線及曲率幅值突變系數(shù)曲線，依據(jù)柔度曲率幅值突變規(guī)律對小雁塔進行了損傷定位識別。結(jié)果表明，結(jié)構(gòu)第2層、第8層及第11層發(fā)生了較嚴重的損傷，損傷程度與柔度曲率幅值突變量關(guān)系密切，且結(jié)構(gòu)開洞對損傷定位識別的顯著性有一定影響。因此，通過進行磚石古塔原位動力測試，依據(jù)模態(tài)柔度曲率幅值突變規(guī)律可實現(xiàn)結(jié)構(gòu)損傷定位，為古塔結(jié)構(gòu)損傷研究提供了參考。
［關(guān)鍵詞］磚石古塔； 動力測試； 動力特性； 損傷識別
中圖分類號：TU311-3文獻標識碼：A文章編號：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
*國家自然科學基金資助項目（51778527，51308455），陜西省自然科學基礎(chǔ)研究計劃資助項目（2018JM5111），陜西省博士后科學基金資助項目（2014）。
作者簡介：盧俊龍，博士，副教授，碩士生導師，Email：lujunlong@sohu.com。
