Study On Dynamic And Static Load Test Of Jiangnan Bridge In Tonghua City

Bridge detection is an important means to evaluate the safety of old bridges. Among the many bridges in our country, the old bridge accounts for more than 85% of the total number of bridges, and most of the old bridge construction in twentieth Century about seventy or eighty years. Old bridge in the design due to the consideration of the bridge traffic pressure and current practice of bridge traffic pressure is insufficient, so most of the old bridge in service during the period of the emergence of crack, deformation even the collapse of the disease, greatly threatened the life safety of the masses.Bridge detection is to evaluate the service condition of the bridge by means of theoretical analysis and experimental data, and further guide the strengthening and maintenance of the bridge. The measured data is the static response and dynamic response measured in the load test, and the appearance of the bridge is also required. In theoretical analysis, now general method is simulated by the bridge special finite element analysis software. MIDAS civil, but Midas civil analysis used is threedimensional truss element, is also a rough comparison of the influence of bridge transverse load distribution of the surface, and in detection of bridge, the bridge deck system in force, will to some extent reduce the measured values and Midas civil software modeling is not easy to model of floor system, which led to the finite element analysis results will appear too large, on the bridge of the actual service performance does not reach the designated position.In this paper, the Jiangnan bridge in Tonghua city as the project, mainly carried out the following research work:1, the South River Bridge on the appearance of detection. Through the development of cracks in the bridge component and the bridge Investigation of the structure of the bridge, the bridge of the force system and the bridge in service status.2, the establishment of the South Bridge of the theoretical analysis of the model, and the theoretical analysis. The theoretical analysis model is divided into general model and precise model, through the comparative analysis to determine the load test conditions and the arrangement of measuring points, so as to guide the design of the static load test. After comparing the results measured by the static load test and the theoretical analysis value, the bearing capacity of the bridge is determined, and the strength and stiffness of the main structure of the bridge are evaluated. Finally, the error of the relative measured value is determined by the fine analysis technology, which has great influence on the bridge detection conclusion.3, through theoretical analysis of the characteristics of the theoretical model of the South Bridge, the further design of the dynamic load test, and determine the incentive method, the location of the measuring point and the sampling frequency. The theoretical characteristic value and the measured value are compared and analyzed, and the dynamic performance of the bridge is obtained. Finally, the error of the measured value is found to have a great influence on the dynamic performance of the bridge.