Experimental Study On Load Of Long-span Prestressed Concrete Continuous Rigid Frame Bridges

With the rapid development of bridge construction in China,in order to ensure the safe operation of bridge structures,it is necessary to test the bearing capacity and evaluate the operation status of existing and new bridge structures.As an important method in bridge testing,load test is a research integrating practice and theory,and plays an irreplaceable role in bridge testing technology.The load test is the most direct and effective method to evaluate the bridge quality,which can evaluate whether the overall mechanical performance of the bridge meets the requirements and provide necessary performance data for the later inspection and operation.Based on the site test of a newly-built bridge in mianyang,the load test of the long-span prestressed continuous rigid frame bridge is studied in this paper.Starting from the basic purpose and significance of load test,this paper summarizes the current research status of load test at home and abroad from three aspects,and finds that there are still a lot of detailed problems in bridge inspection and evaluation in China that need to be improved.This paper summarizes the basic theory and method of bridge load test,and studies the scheme of load test.The continuous rigid frame bridge studied in this paper is modeled by beam element and its deflection and stress are simulated by finite element method.According to the influence line of the bridge under the design load,the corresponding test scheme is developed.At the same time,the load condition,test section,load and measurement point layout are studied.In this paper,the method of comparative analysis is used to compare the actual measured de formation value and stress value of the control interface of each working condition obtained by the static load test with the theoretical calculation value,and calculate the structural verif ication coefficient to achieve the evaluation of the actual bearing capacity of the structure.T he ultimate goal.Modal for the bridge,sports car,vehicle and brake test,obtained under vehicle load indices such as dynamic strain and displacement of the bridge structure,and,according to the modal analysis by the finite element model of bridge is the bridge of the actual impact factor and natural frequency of vibration,etc.,and compare the measured values and the theoretical value,the dynamic performance of the analysis of the bridge.Comparing the actual observation value and the theoretical calculation value,the actual work ing state of the bridge is evaluated,which shows that the bridge meets the specifications in t he actual use state.Based on the analysis of the factors affecting the load test results,the pa per summarizes the load test of this rigid frame bridge,and puts forward some Suggestions and Suggestions for improvement,so as to provide some experience for the design and loa d test of other continuous rigid frame Bridges of the same type,as well as theoretical basis f or the test and maintenance of this bridge in the future.