Research On Train-induced Vibration And Comfort Of Two-storey High-speed Railway Station

High-speed railways feature prominently in fast transportation,good comfort and high safety,providing significant convenience for people to travel.The high-speed rail stations,as the connection node of the high-speed railways,are designed for passengers to wait for their trains and to transfer.While,with the changes in the function and structure of high-speed railway stations,more attention has been paid to issues like vibration,noise and comfort level.This paper studies the structural vibration characteristics of the novel double-deck high-speed railway station when the train is in operation,where theoretical analysis,numerical simulation and field measurement,etc.,are made.The main contents and findings are as follows.（1）A theoretical analysis of train-induced structural vibration is conducted.First,the mechanism of train-induced vibration is explained,and the track irregularities that will lead to excitation of wheel-rail vibrations are introduced.Then,the general laws and characteristics of the train-induced vibration of three types of railway rail transit system are discussed.In addition,existing standards and indicators for railway vibration are summarized,so as to theoretical basis for subsequent analysis and evaluation.（2）A finite element model of the double-deck high-speed railway station is established.Taking the Fengtai Railway Station as an example,which is the first double-deck station in China.Based on the structural symmetry,parts of the station are selected for modeling,which cover eight sets and 15 lines in total within the two floors.Then,the natural vibration analysis is made,which indicates that the vertical,local vibrations constitute the main vibration of the passenger-station structure.The same modeling method is used to establish the finite element model of the Tianjin South Station,so as to verify the modeling method by comparing with the measured data in the Tianjin South Station.（3）The vibration characteristics of the station structure under train load are analyzed.Twelve analysis cases are defined according to the train speed,the number and location of roads,and whether the roads have been covered with the roadbed damping pads.The calculation results show that the vibration peak at the elevated platform is concentrated at about 40 Hz,while around 60 Hz at the ground platform,showing that the elevated system has the advantage of lower vibration intensity compared to the ground system.In general,the structural vibrations will get increased when there are more driving trains,or being closer to the driving trains,or there are faster passing trains.In those cases,the vibration-influenced area of various platforms will also get significantly expanded.The vibration response of double-deck driving building is greater than that of single-deck driving building;besides,the vibration peak of the double-deck driving is higher than that of single-deck driving building,while lower than the sum of that of the upper and lower single-deck building.Moreover,the roadbed damping pad can effectively reduce the vibration response,and the damping effect is related to the thickness and material characteristics of the pad.It is found that the damping pad with a small static modulus plays a better role in reducing vibration.（4）The comfort level of the train-induced vibration of the station structure is evaluated.Two areas,i.e.the platform and the station hall,are classified according to their functions.According to relevant research and standards,it is defined that the limit of platform area is86 d B,and station area is 75 d B.According to the analysis results,both the two areas can meet the requirements of vibration comfort level for the twelve analysis cases in this paper.