强震仪观测资料在杨浦大桥养护监测中的运用

上海杨浦大桥是当时世界同类型桥梁中最长的斜拉索桥,为了掌握大桥的运行情况,确保运行安全,每年用在该桥上的养护管理费用相当可观,且程序繁琐。如何找到既简单实用,又节约费用,就能起到一定的养护监测作用的方法?是本文探讨的问题。本文运用强震观测资料,采用自回归移动平均ARMA模型,得到大桥的随机振动中某些振型的频率及阻尼比,在地震、台风过后或经一长段时间车辆运行之后,看其相应振型频率和阻尼比的变化,以达到维护监测的目的。从所得的结果看,此法具有较好的可操作性,可用于大桥主塔等的养护。

Application of Records of Strong-Motion-Seismographs in Maintenance of the Yang-Pu Bridge

The Yang Pu Bridge was the longest among the same type of suspension bridges in the world at the time of construction. In order to identify its operative performance and ensure safe operation, a lot of money and work time have been spent in the maintenance of this bridge every year. This paper focuses on how to develop a more efficient and economical procedure for bridge maintenance. The ARMA model is employed and some seismic frequencies and damping ratios are obtained from data of random vibration of the bridge. After an earthquake, a typhoon, or some long duration of operation, variations in these frequencies and damping rations are checked, on which bridge maintenance is based. It is demonstrated from the preliminary results that the proposed method is applicable for maintenance of the main towers of the bridge.