Research On Strain Testing Technology Within Bridge Monitoring

Domestic bridge construction in the past30years has made great achievements，As widely used monitoring technology has played an important supporting role.However summarize past experience of construction monitoring can be found in thestrain test (stress monitoring) the prevalence of large errors based on vibrating wirestrain sensor. Strain measurement technology whin bridge construction monitoringrequires further research.In this paper, under the auspices of "highway bridge construction monitoringtechnical specifications" project, Relying on a main span of200meters constructionmonitoring of Tongzi River Bridge,Within two box girder sections, strainmeasurement points arranged in eight(After a measurement point of failure, there onlybeen7effective points), While using vibrating wire sensor and FBG sensor, under thesame conditions of the real bridge monitoring as the construction process carried out,through monitoring data collection and analysis,then got the main conclusions:①There were14stress test curve of7test points. Before the processing ofstrain drift, the results show a consistent trend of the stress test curve and thetheoretical curve but with large errors, data of the box girder’ upper deck, errorsdistributed in the range from0to60%. The errors were much greater of the buttondeck points’. Only a FBG sensor’s test curve was in good agreement with thetheoretical value.②After the processing of strain drift. Errors of the data of3FBG sensors in theupper deck are mainly distributed in the10%~20%, part are beyond30%, errors of thedata of3vibrating wire sensors in the upper deck are mainly distributed in less than10%. Only a value’s error is beyond20%. The test value distribution and the meanabsolute error of vibrating wire sensors is smaller than FBG’s. Comparison of the twosensors’ test data shows that:Both the twice sensors’ errors of measured data are large.③Strain analysis of the test data shows that the two kinds sensors’ testdeviation are generally the same whin the strain monitoring of bridge construction.