Load Test Research Of Long-Span Tied-Arch Bridges

As a new form of arch bridges, the tied-arch bridge is wildly developed and applied in the modern city bridge. With its strong spanning ability, reasonable stress and beautiful modeling, the tied-arch bridge is favored by numerous engineers. With the increase of the span and the complex of structure, the load of the whole bridge is necessary to be tested. The test can intuitively and accurately reflect the quality and safety of bridge. The comparison of the load test data and design data can accumulate experience for bridge designing theory, improve construction technology, conservation and management and increase service life of the bridge.Bridge loading test includes relevant tests, recording and analysis based on loading directly on the bridge structure. In order to understand the bridge structure under the real working condition, to evaluate the construction quality of bridge structure and using conditions, to provide scientific basis for completion acceptance and in-depth exploration, test preparation, theoretical calculation, field test and analyzing experimental results are to be done in the test.This thesis carries out the following work,1. Establish the finite element model of Caiyuanbachangjiang Bridge using finite element analysis software MIDAS/Civil20102. Formulate static load test scheme of the main bridge of Caiyuanbachangjiang bridge, determine the loading mode, load position, control section and the loading tonnage. Bridge deck, main arch bridge linear and various test section stress, deflection of main girder in the condition of static loading. The test results show that, the bridge structure design is reasonable, and the bridge has enough strength and stiffness.3. Formulate dynamic load test scheme of the main bridge of Caiyuanbachangjiang bridge, the theoretical natural vibration frequency and mode are obtained after analyzing the finite element model. Natural vibration characteristics, damping ratio and driving vibration are tested in the dynamic load test, the impact effect of the bridge structure under various driving vibration is analyzed. The test results show that, the dynamic characteristics of the bridge is very good.