Safety Evaluation Of Donghuayu Aqueduct Bridge

The Donghuayu Aqueduct Bridge located in Meixian County in Shaanxi Province was first built in 1980's. Its structural form was rib arch with simple hole and frame supporting. At present, whereas so many reasons such as its using function changing from irrigation to city water supply, the increasing of importance, the original design standard on the low side, the damage and aging of structure, the demand for seismic fortify in strong earthquake region and offering data of technical alteration for adding flux aftertime, it is important for safety and seismic capability of this aqueduct bridge.This paper has evaluated testing in site, structural analysis and seismic. In the testing on the spot, with the method of undamaged testing for priority and drilling core for supplement, the author gets the concrete intensity of main components. The author has adopted SAP2000 procedure to make 3-d static and dynamic analysis and obtained the designing internal force, displacement and dynamic characteristic parameter of each element under different load cases. The seism response analysis of aqueduct bridge is analyzed with modal superposition method based on response spectrum which participant mode of vibration chooses the former 1 0 steps and combinatorial method was SRSS.For the safety evaluation of Donghuayu Aqueduct Bridge, the main problem is that no seismic design code is valuable. This paper has benefitedinfrom close trade's experiences and combined with the trait of this aqueduct bridge to bring forward the method of classification evaluation, which was successfully used in the evaluation of this aqueduct bridge. It also has important reference value for the similar construction.By the safety and seismic evaluation of this aqueduct bridge, it has shown that (1) Besides the structure of this aqueduct bridge was basically unharmed without some flake of concrete cover and revealing stirrup, its intensity basically reached the need of primary design. (2) From the side of carrying capacity, rib arch could satisfy the needs under the action of wind and earthquake, but some individual frame crossbeams and most rib arch tie beams couldn't satisfy the need. The load case reckoned in horizontal earthquake action was design control load case. (3) From the structure measure, each element couldn't satisfy the need completely. It should be emphasized that the equipments that hadn't set drop-prevent beams were not matching the need. (4) While the using of the aqueduct bridge had needs to be adjusted, seismic reinforced measure should deal with servicing and alteration. (5) In the method of reinforcing, it should be mentioned that the reinforce part must combine with the former structure element to guarantee the associated force of the reinforce part when considering earthquake shock. From above conclusion, the author suggests that it is prior to adopt the fixing measure with local outer-wrap reinforced concrete cover.