西堠门大桥正交异性钢桥面板静载和徐行试验研究

Static Load and Crawl Test Study on the Orthotropic Steel Deck of Xihoumen Bridge

基于西堠门大桥正交异性钢桥面板静载和徐行试验,研究在汽车轮载作用下正交异性钢桥面板关键构造的应力大小、历程和分布规律。试验结果表明,在3轴30t试验车作用下,纵肋底板跨中测点的纵向应力最大,达51.7MPa,横隔板开口上缘测点的最大主应力次之,为30.8MPa,面板上测点的最大横向应力较小,为16.7MPa。面板横向应力、纵肋腹板竖向应力的纵向影响线长度约为2倍横隔板间距,横隔板开口上缘主应力的纵向影响线长度约为1.5倍横隔板间距,纵肋底板纵向应力的纵向影响线长度约为3倍横隔板间距。运用泄水法对徐行试验测得的应力历程进行分析,得到钢桥面板关键构造的应力振动幅值大于5MPa的次数分别为:纵肋底板跨中纵向应力3次,最大应力振动幅值为60.1MPa;面板横向应力3次,最大应力振动幅值为26.8MPa;纵肋腹板竖向应力4次,最大应力振动幅值为16.1MPa;横隔板开口上缘主应力2次。运用AN-SYS软件提供的SHELL181单元建立钢箱梁节段模型进行静力分析,计算结果与实测结果基本一致,表明SHELL181单元能够模拟钢桥面板的受力特征。

The static load and crawl tests on the orthotropic steel deck of Xihoumen Bridge were performed to study the stress magnitude,the history curve and the distribution law of the key structure details of the orthotropic steel deck under traffic loading. The results of the tests reveal that,under the action of the three-axle 30 t weighted test truck,the longitudinal stress at the midspan measuring point of the longitudinal rib bottom is 51.7 MPa,which is the biggest. The maximum principal stress at the measuring point of the upper edge of the diaphragm opening is smaller,which is 30.8 MPa. The maximum transversal stress at the measuring point of the deck is 16.7 MPa,which is the smallest. The longitudinal influence line of the transversal stress on the deck and the vertical stress on the web of the longitudinal rib is about 2 times of the diaphragm distance. The longitudinal influence line of the principal stress at the upper edge of the diaphragm opening is about 1.5 times of the diaphragm distance. The longitudinal influence line of the longitudinal stress on the bottom of the longitudinal rib is about 3 times of the diaphragm distance. The stress history obtained from the crawl test was analyzed by sluicing method. The vibration numbers for the key structure details of the steel deck under the condition that the stress amplitude was larger than 5 MPa were obtained as follows. The longitudinal stress on the midspan of the longitudinal rib bottom is 3 times and the maximum stress amplitude is 60.1 MPa. The transversal stress on the deck is 3 times and the maximum stress amplitude is 26.8 MPa. The vertical stress on the web of the longitudinal rib is 4 times and the maximum stress amplitude is 16.1 MPa. The principal stress at the upper edge of the diaphragm opening is 2 times. The section model of the steel box girder was established by the SHELL181 element of ANSYS to carry out the static analysis. The calculated results are basically the same with the measured ones,which show that the SHELL181 element can well simulate the mechanical behavior of the orthotropic steel deck.