| With the rapid development of high speed railway, a number of representative elevated railway stations have been built in Europe, Japan, South Korea and China, each of which has become a major transport hub integrating railway, subway, bus, aviation and other modes of transportation. Now the common structure style of elevated railway stations is“structural integration of vehicle, bridge, and the station building". In this station, the columns of overhead waiting hall sit directly on the traffic bridge structures under the waiting hall. When a railway multiple-unit with a high speed passes through, the vibration induced by train is directly transferred to the overhead waiting hall floor. However, due to the fact that overhead waiting hall floor is long spanned, light weighted, with a lower self-excited vibration frequency, passengers in waiting hall tends to feel uncomfortable when a high speed train passes through.Therefore, with reference to the project of Vibration and Noise Test in Changsha South Station during integration test of Wuhan-Guangzhou High Speed Railway, the law of vibration transmission is obtained after analyzing the data obtained from station vibration test. And 4 criteria are used to evaluate the waiting environment in the elevated railway station, which are GB/T 13441.1-2007“Mechanical vibration and shock-Evaluation of human exposure to whole-body vibration-part 1:General requirements”, BS 6472-1:2008 “Guide to Evaluation of Human Exposure to Vibration in Buildings(0.5Hz～80Hz)”, ISO 2631-2“Mechanical vibration and shock-Evaluation of human exposure to whole-body vibration-Part 2: Vibration in buildings”, and US ATC“Reducing Floor Vibration Design Guideline”. The conclusion about vibration comfortability of floor varies with different evaluation criteria.In this paper, the vehicles-ballastless track-bridge coupling dynamic analysis program is improved by adding ballastless track model and spring-damper element model to ameliorate the existing ballastless track model in dynamic analysis. Due to the fact that ballastless track model and spring-damper element model include the track slab’s own flexibility and the stiffness and damping between track slab and bridge, improved program can not only be applied to vehicles-ballastless track-station coupling dynamic analysis and vibration attenuation optimization analysis but also enrich the function of simulation program. It makes up a disadvantage that the previous vehicles-ballastless track-bridge dynamic analysis program can not analyze the vibration attenuation structures. Further more it provides a mean of dynamic response analysis and vibration attenuation optimization’s evaluation abased on large-scale complex elevated railway station.Taking Changsha South station as a research background, vehicles-ballastless track-station coupling dynamic analysis program is used in this paper to do simulation calculation about a elevated railway station. The simulation calculation result is compared with the site vibration test to modify the calculated parameters to make them coincide. Through comparative analysis, the correctness of the theoretical models and the dynamic program are verified.Simulation means is used to analyze factors that affect station vibration, such as train speed, model of car, train passing through the station on single (double) line, rigidity of track, track irregularity. Single factor fitting is adopted for factors which affect station vibration. Based on above fitting, a vibration theory analysis is established under influence of multi-factor. Through theoretical analysis, using vibration acceleration amplitude as an evaluation indicator of floor vibration comfort is proposed. The peak acceleration can be obtained of overhead waiting hall floor, including vibration caused by high speed train operation and floor vibration caused by walking.Based on German DIN4150 standard, the limit of floor peak acceleration is derived, and the overhead waiting hall vibration is evaluated of Changsha South Station. With combination of site vibration test of Changsha South Station and elevated station structure style of Beijing-Shanghai HSR, a peak acceleration is proposed to this kind of structure for HSR elevated stations, i.e., peak acceleration of elevated station floor for HSR is suggested to be less than 0.4 m/ s2.As the main railway line bridge in Changsha South Station is not separated from main station building, vibration will be passed to overhead waiting hall through bridge piers and platform columns on piers, which will cause vibration of waiting hall floor. On condition that main structures of station building will not be modified large-scaled, this paper designs vibration attenuation optimization schemes for 3 track structures and 1 bridge structure, which are:①introducing steel spring floating slab track which are extensively used in MRT into HSR track structure, and limit their lateral and longitudinal deformations, and the vibration decreases by 25%.②improving elasticity of rubber tie-plates under rail, and the stiffness is suggested to be at 16.7 kN/mm~58kN/mm, and when the stiffness takes 16.7kN/mm, the vibration of the waiting hall floor decreases by 13%.③laying rubber cushions under track slabs to improve elasticity of track slabs, which results in a vibration-reduction track slab and the floor vibration decreases by 10%.④adopting MTMD vibration control of the main railway line bridge, and the bridge vibration at mid-span decreases by 35%, and the floor vibration decreases by 10%.The effect of the first optimization scheme is obvious, but the project costs higher and vibration of car increases along with the decease in track vibration. The effects of the back three options are basically the same. Taking into account the stability of jointless line and practical operability, it is suggested that the third scheme is an appropriate vibration attenuation scheme, namely laying rubber cushions under track slabs, which not only costs lower but also makes routine maintenance easier. |
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