The Dynamic And Static Behavior Analysis And Load Test Of Prestressed Concrete Continuous-Box-Girder Bridge

Nowadays, with the rapid development of national economy of our country, many new types of bridges are used in the wide of China, such as large span bridges, cloverleaf junctions and complicated viaducts. Dynamic and static tests are needed in order to get hold of the main construction characteristics indicators; based on these basic test data, they will be analysed with the theory results to evaluate the structure quality, in order to ensure the structure behaviors and forced conditions must be fayed in with the requirement of designing standard and safety. At the same time, these basic test data can verify the bridge design theory and construction quality, and give a reference of the bridge management and maintainment, which is one of the most important key stages of bridge construction.The purpose of this paper is to take the case of the Baihe bridge test, the bridge is the part of Xinyang-Nanyang in Henan of Shanghai-Xian freeway, the total length of the bridge is 1560.2m, the skew angel of bridge axes and Baihe is 85°, five span prestressed concrete continuous box girder of varying section depths is used in Baihe bridge main section depths, Span reorganize: 56m+3×100m+56m, and separate section is used in the bridge, half bridge breadth is 16.75m, central separating breadth is 1.0m ,single box-single section inclined web is used in half bridge, the contrast of web inclined highness and breadth is 5: 1. The bridge has opened to traffic in 2006.12. To test whether a prestressed continuous box girder bridge qualifys for the safe property, then provides scientific data for the subsequent management, the load test scheme is designed according to the initial data of the designing and construction. Some following conclusions are drawn through the test results combined with finite element analysis.1. The testing of dead load. The average strain-verify-coefficient of the box-girder section of the main bridge in the different simulation load conditions is between 48% to 67%; the average deflection-verify-coefficient is between 58% to 60%. The results indicate that the bridge structure is in the flexibility condition, the rigidity and bearing capacity satisfies with the design, the bridge is safe; the strain and deflection of the box-girder section is according with the plane hypothesis under the side load, this indicates the torsion strength is good.2. The testing of live load. The testing results indicate that the measured impact coefficient can approach to the theoretical values of the design impact coefficient. The testing results indicate that the bridge has the specific integral strength and rigidity, and the bearing capacity measured up to the design requirement. 3. The load transverse distribution coefficient is homogeneous, which shows the whole forced condition is good. The results of finite element calculating are near to the test results, which accounts for the feasible test scheme and the test data.4. The dynamic conclusion is same to the static conclusion, further more, it corresponds with the fact.The conclusions and actual test data have supplied the science information for the bridge management.