用GPS和随机减量技术对悬索桥实时监测

On-line monitoring of suspension bridges using the GPS and the random decrement technique

为连续实时监测大跨桥梁的抗风、抗震重要参数——位移、转角和频率 ,通过比较几种桥梁传统的位移测量方法 ,提出利用 GPS实时监测悬索桥位移和转角的新方法。介绍了其测量系统和特点 ,在此基础上 ,利用基于随机减量的 FFT时域模态识别技术对虎门大桥进行实时模态分析 ,并同有限元数值分析结果和加速度计的实地测量结果相比较 ,得出

A new measurement method using the GPS was introduced for on-line monitoring of a long-span-bridge's wind-resistant and seism-resistant parameters. The GPS-based measurement system was described by comparing several displacement measure techniques. A time domain modal identification method was used with the GPS data for real time monitoring of the Humen suspension bridge. The results compared well with those obtained from 3-D FEM numerical analysis and field measurements using accelerometers. The results show that the GPS technique combined with the random decrement technique can be used for on-line monitoring of long span bridges.