Health Monitoring Research Of Curve Beam Bridge Based On Optical Fiber Technology

With the construction of Expressway and urban viaduct,curved girder bridge is widely used in Interchange bridge.Due to the curved girder bridge has the advantages of simple structure,large span,their health status is often neglected by people,but due to the curved girder bridge's own structural characteristics,in the process of operation,often because of vehicle centrifugal force and lateral deformation and creep displacement,lateral creeping or even as a result of excessive pier bottom cracking void or support.In order to ensure safe operation of structure safety and vehicle curve girder bridge,it is necessary to monitor the health status of the curved girder bridge,discovered its existence in the process of operation as soon as possible,and to take timely treatment and reinforcement measures.In this paper,Zhengzhou City Garden interchange F ramp project,set up a health monitoring system of curved girder bridge with fiber grating technology,and the measured data for more than one year analysis of curved girder bridge health.The main research contents and achievements are as follows:1 The establishment of the Huayuan Road interchange F ramp bridge finite element model using finite element method,obtained a bridge under self weight,prestress load,two dead load,vehicle load and temperature under different combinations of the girder should be relative displacement between the force and the pier pier and main girder,and provide basis for evaluation of the sensor layout and health status.2 Fiber Bragg grating sensors are installed in the stress control section and the deformation control section.A curve beam bridge health monitoring system which integrates optical fiber displacement,stress,acceleration sensor and data demodulation,remote acquisition,control and analysis is established.3 Based on the function of MATLAB in GUI,the health monitoring and analysis software for F ramp bridge of Huayuan Road interchange in Zhengzhou is compiled.The software has the functions of direct extraction,analysis,drawing and display of a large number of monitoring data.4 The displacement,strain,acceleration and temperature measured data of the system running for one year are analyzed and studied,and the force state of the bridge is visually displayed by the image.The data analysis shows that the maximum stress of the curved girder bridge is less than the design strength of the material,and the maximum displacement,especially the transverse creep is less than the standard allowable deformation,and the bridge is in a healthy state.5 Using bridge bearing capacity coefficient to determine bridge safety reserve size.The data calculation shows that under the normal vehicle load,the safety reserve of F ramp bridge of Huayuan Road Zhengzhou interchange meets the design requirements.And further calculation coefficient of bearing capacity under different vehicle loads,the bridge weight which can predict.