Life Circle Monitoring And Assessment Technology Of Continuous Rigid Frame Bridge During Construction And Operation Period

Construction controlduring the bridge construction period and healthy monitoring during the operation period play positive roles in safety guarantee of the bridge. Currently, these two aspects both tend to be relatively independent and have not formed a integrated monitoring mode resulting in a lack of integrity and consistency of bridge monitoring information. On the other hand, bridge health monitoring includes the massive information. However, due to too many uncertain factors, such as materials, structure combination, working environment and test signals, the techniques and bridge safety assessment of bridge are not formed systematically. Therefore, the efficiency of bridge health monitoring is greatly affected. Under the context above, this paper takes a continuous rigid frame bridge as research subject, studies the life-cycle monitoring mode and practical evaluation techniques for large bridge during the period of construction and operation. The main researchinclude:①Based on the comparison and analysis of the monitoring contents and projects of the large bridge during the construction and operation period, using the correlation and "Connection" of the monitoring information of the pre-embedded and surface sensor, the concept of life-cycle monitoringof the large bridge is proposed duringthe construction and operation period. The principles, work pattern and advantages of the life-cycle monitoring areelaborated specifically. Because of the huge amount of information of the stress monitoring for the bridge during the construction and operation period and the possible phenomenon of deficiency and the problem of the "noise" factors which are contained in the signal, this study used the neural network method to repair the incomplete data and the technique in noise elimination of the monitoring information using Signal de-noising technique based on Wavelet Theory.②From the view of the stress monitoring, referenced the concept of strain testing coefficient in loading test, the envelope assessment technique of stress testing coefficient of large bridge is presented based on the monitoring information. With the analysis of live load, temperature and initial stress, this paper studies the safety assessment technology of large bridge based on the allowable stress envelope.③From the view of the deflection monitoring, a safety assessment technology of large bridge based on the envelope of deflection coefficient is proposed, combined with the characteristics of the deflection measurement and data envelopment analysis, and the concept of deflection coefficient in loading test. Combined with the limit of allowable deflection in the design codes of bridge, this paper studies the safety assessment technology of large bridge based on the envelope of allowable deflection.④Finally, this paper selects the Fengdu Longhe bridge with a240m main span,as a case study.It illustrates and proves how to achieve the life-cycle monitoring with the correlation and "Connection" of the monitoring information of the pre-embedded and surface sensor, based on the information of the bridge construction monitoring during the construction period and the healthy monitoring information during the operation period. Meanwhile, it completes the safety assessment of the bridge with the measured data, based on the stress monitoring and the deflection measurement. Comparing the results of the assessment and loading test of the bridge shows that the techniques of bridge safety assessment based on the envelope of the stress and deflection is reasonable.The life-cycle monitoring mode and evaluation techniques of the large continuous rigid frame bridge during the construction and operation period provided in this paper have an positivesignificance in ensuring the safety of bridge structure, implementing life-cycle monitoring and assessment, and have a good promotion in further applying.