A BWIM Method Used for Steel Truss Bridges

Through layout of the strain measurement points on the steel truss bridge,the dynamic stress in the bridge was monitored and the data of the strain history were acquired.By using the filtrated data of stress monitoring,the BWIM(Bridge Weigh in Motion) Method was used to reversely calculate the load on the bridge and the load of the vehicles actually passing the bridge was obtained.The Method was used to reversely calculate the load on two practical bridges and the vehicles passing the two bridges were all identified.The statistical vehicle load distribution on the bridges agreed well with the actual vehicle load distribution.Practice proves that the Method has little interference on the traffic on the bridges,is simple and easy to be used,the data acquisition is complete and the operation cost is low.The method is of certain accuracy when applied to the reverse calculation of the traffic load on the long span continuous steel truss bridges and can collect various information including those of the traffic volume,vehicle load,vehicle speed and vehicle front spacing distance.