Load Test Researchon Multi-Span Hyperbolic Arch Bridge

As a kind of old bridge type, the arch with the technical advantages of large span capacity, strong bearing capacity, easy obtaining to the material, reasonable cost, low maintenance cost and elegant shape has become the oldest building, strong competitive, a widely used form of bridges in our country’s highway bridges. On the basis of the traditional arch bridge in our country, we creatively built a new bridge style of hyperbolic arch bridge with a good mechanical performance which has been widely used in the bridge construction of our country.Since the reform and opening up, our country’s economic construction has made great progress. Along with the rapid increase of traffic volume and overweight vehicles, disease problem of the arch bridge and the bearing capacity problems have also been increasingly prominent. In order to better implement the service function of these bridges, we need the necessary of the bridge detection and evaluation. Implementation of the bridge load test is an important means of the test evaluation.First of all, according to the relevant specification and combined with relevant test results, we can use special bridge calculation software Doctor Bridge to establish finite element model and make a assessment of the whole bridge structure’s bearing capacity.On the basis of the evaluation results meet the requirements of bearing capacity, using the finite element analysis software Midas/Civil to establish finite element model of multi span hyperbolic arch, according to the stress of the bridge type and characteristics of internal force calculation to determine the load and control section, classification of adding or uninstalling load, termination of experimental conditions and test content, method, the measuring point layout, equipment selection, data processing, curve drawing, etc. Through the static load test, the loading condition of each measuring point’s strain and deflection are obtained, then compared with the theoretical calculation value analysis again to check whether the actual bearing capacity of the bridge meet the design or carrying capacity under current traffic requirements.In the dynamic load test, take the running car and vehicle test to implement certain incentive effect for bridge structure to make the bridge structure produces vibration, and through certain parts of the bridge dynamic time history response of the collection, analysis the dynamic parameters of the bridge, compared with finite element model of the theoretical value, and on this basis to evaluate the using state of the structure of the bridge.