Study On Design Parameters Of Collapse-proof Restrict Device For Railway Simply Supported Bridge In High Earthquake Intensity Area

Unseating of superstructure at the expansion joints and abutments is the primary reason for collapsing of bridge during earthquake. If the seismic force was beyond the strength of structure, the bearings would be destroyed. When the lap length is shorter than the relative displacement between beam and pier, the superstructure will collapse. The restrict system is a new technology, which could reduce seismic and enhance structure; decreasing the relative displacement to prevent superstructures collapse from the bearing is the primary function. The girder falling in the earthquake have aroused many scholars’attention, in recently years, many a researches have got some extent achievements. But the design method of restrainer system, researches about parameters optimization of restrainer system and the product development still have many problems. In specially, such research is in the start stage in China. Although some actually projects have used the restrainer and unseating prevent device, we just considered that as a detail of design, which is lack of corresponding theoretical analyses. So, it is the high time to do some researches in such field.This paper in order to solve the existed problem, which is the design of Restrict device for railway simply supported bridge in high earthquake intensity region in our country, studying the influence rule of parameters of restrainer device, the factors of restrainer efficiency and the optimization of parameters restrainer system. The main research works are as follows:1. Setting up two simply supported bridges FEAM, systematically study the influence factors of restrainer efficiency of Collapse-proof Restrict Device, and optimize the parameters of longitude restrainer device.(1) Comparing to the domestic and foreign experts and scholars’design methods to longitude restrainer, and the advantages and the disadvantages of various methods which could provide meaningful reference for our country’s longitude collapse-proof design.(2) By establishing FEAM,8kinds of high piers, andl1kinds of restrict stiffness ratio, based on dynamic time-history analysis, we can get the influence rule of restrainer device to restrict efficiency.(3) To compare the restrict efficiency of different longitude restrainer devices, it is concluded that the single pull model of longitude restrainer device is better.2. Setting up a two simply supported bridge FEAM, systematically study the influence factors of restrainer efficiency of Collapse-proof Restrainer Device, and optimize the parameters of transverse restrainer device.(1) Setting up transverse collapse-poof FEAM, using concrete’s plastic damage constitutive model, then getting the ultimate bearing capacity of transverse block.(2) Studying the restrict effect of the transverse restrict device by the clearance between girder and transverse restrict device systematically. By the calculation results based on ABAQUS finite element software, we suggest the value scope of clearance is from4centimeter to6centimeter.(3) Researching the influence rule of the transverse restrict device, such as the stiffness of bearing, the stiffness of block and the seismic wave.3. Setting up two simply supported bridges FEAM, choosing7groups actual seismic wave as vertical dynamic incentive, based on dynamic time-history analysis of the whole bridge, the calculation show that when the bearings are damaged, the vertical relative displacement of pier and girder is relatively large. However, when the bearings are not damaged, the vertical relative displacement of pier and girder is relatively smaller, and we needn’t make a restrict design, just to check the sliding resistance and so on. Through calculated.4. Studying the restrict efficiency by the stiffness of the restrainer device under the combinations of seismic wave of longitude+vertical and transverse+vertical, after the bearing was damaged. Then comparing two cases’restrict effect with and without the vertical restrict device, the results showed that the restrict effect would be decreased under three-direction seismic wave, longitude+transverse+vertical. We must pay attention to this rule in collapse-proof restrainer device design in future.