Shaking Table Test Of "Integrated Station-Bridge" High-Speed Railway Station Structure

The system of "Integrated Station-bridge" high-speed railway station structure is an important type of large-scale transportation hub station.As an important transport node project of the city,it has the characteristics of complex structure and uneven distribution of mass stiffness.At present,there is a lack of unified code for seismic design specifications.The research on dynamic response characteristics and failure mode of this kind of structure under earthquake is not comprehensive.Therefore,the typical "Integrated Station-bridge" high-speed railway station structure is taken as the research object.Combining shaking table test with numerical analysis,the dynamic response characteristics of such large and complex station structures under earthquake are systematically studied.The main contents are as follows:(1)Establishment and analysis of "Integrated Station-bridge" high-speed railway station structure.The structure model of high-speed railway station is established by using finite element software.The natural vibration characteristics and the response spectra in the elastic stage are analyzed.Dynamic characteristics of high-speed railway station structure and seismic response characteristics in elastic stage are obtained.The response spectrum based dual-band control method is used to select appropriate input ground motion records.Dynamic elastoplastic analysis of structure under rarely occurred earthquake is carried out.The dynamic response characteristics of high-speed railway station structure under ground motion excitation are studied.The results show that the in-plane layout of such station structure is regular,but the grid structure is greatly affected by higher order vibration modes.The prototype structure of the station can meet the seismic fortification targets under small and large earthquakes.(2)Design of shaking table test model,fabrication and installation of test model,and load test plan determination.According to the similar dimensional analysis,the similar relationship between prototype structure of high-speed railway station structure and test model structure is determined.Then,according to the bearing capacity of the test equipment,the additional mass of each layer of the test model structure is reasonably arranged.The dynamic similarity constants of the test model structure are derived.The values and frequencies of the input ground motion acceleration are adjusted to ensure the dynamic similar relationship between the test model and the prototype structure.Finally,according to the dynamic response characteristics of the prototype structure,representative points are selected as measuring points for sensor arrangement.So far,the fine design of the shaking table test model has been completed.(3)Based on the shaking table test results,the dynamic response characteristics of this type of high-speed railway station structure under earthquake action are analyzed.The shaking table test with scale ratio of 1/25 is carried out and the accuracy of the test model structure is verified by analyzing the natural frequency.The acceleration,displacement,layer shear force and dynamic stress response of the test model structure under earthquake are analyzed,and the dynamic response characteristics of the structure under different seismic intensities and ground motions are obtained.Based on the failure phenomena of test model structure,the failure mechanism and weak points of this kind of large station structure are summarized.The results show that the secondary trusses and waiting floors of the "Integrated Station-bridge" structure are the first to be damaged.It is the weak part of the whole structure.There is a risk of collapse of the waiting floor under the action of huge earthquake,and part of the seismic isolation measures can be added to improve the overall seismic performance of the structure.(4)The finite element model of shaking table test model is established,and the accuracy and reliability of shaking table test model design are verified by means of finite element analysis.Through eigenvalue analysis of the finite element model,the good dynamic similarity between the shaking table test model and the prototype structure is verified;The dynamic elastic-plastic time-history analysis of the finite element model under different earthquake intensity is carried out,The dynamic response analysis results of the model structure obtained from the test are compared with the time-history analysis results,it not only proves the accuracy of shaking table test model design,but also verifies the reliability of shaking table test.There are 63 pictures,45 tables and 139 references in this paper.