Study On Environmental Vibration Characteristics Of High Speed Railway With Profiled Steel Sheet Concrete Composite Floor

Train operation will bring negative effects such as vibration and noise to the surrounding environment along the line,and the vibration of adjacent buildings caused by train operation has attracted more and more attention.Prefabricated structure has become the main structure form in the process of building industrialization because of its advantages of good efficiency and high quality.Profiled steel sheet concrete composite floor is one of the floor structure forms of prefabricated structure.In 2021,China promulgated the outline of national comprehensive three-dimensional transportation network planning,which proposed to vigorously develop railway and other transportation.Therefore,the influence of high-speed railway environmental vibration on profiled steel sheet concrete composite floor will become increasingly prominent.It is necessary to study its vibration under the action of train and master its railway environmental vibration characteristics and propagation law.In this paper,based on the experimental study of profiled steel sheet concrete composite floor,the three-dimensional solid model,isotropic model and orthotropic equivalent model of the floor are established based on the thin plate theory;then the finite element model of track subgrade soil prefabricated structure floor is established,and the railway environmental vibration response of the profiled steel sheet concrete composite floor is solved,and the results of the same size are compared Finally,the influence of train distance and train speed on the environmental vibration of high-speed railway floor is studied.The main conclusions are as follows: the larger the span of profiled steel sheet concrete composite floor is,the smaller the fundamental frequency of the floor is,and the greater the vibration response acceleration is when it is excited in the middle of the span;the larger the frequency of excitation load is,the greater the vibration response acceleration of the composite floor is,and the greater the increase amplitude of the vibration response acceleration is;the fitting comparison of orthotropic equivalent model for profiled steel sheet concrete composite floor is also given The results show that the model is accurate,and the calculation efficiency is high;the vibration modes of the prefabricated structure and the cast-in-place structure are almost the same,and the natural vibration frequency of the prefabricated structure is less than that of the cast-in-place structure;under the action of train,the vibration frequency of the profiled steel plate concrete composite floor is 0 ～ 30 Hz,which belongs to low frequency vibration,and the vibration is within the range of human perception;the peak vibration displacement of the prefabricated structure floor is less than that of the cast-in-place structure Under the action of train,the peak value of horizontal X-direction displacement and vertical Zdirection acceleration of profiled steel sheet concrete composite floor is the largest,and the range and dominant frequency of acceleration spectrum of floor are basically unchanged with the increase of floor thickness,while the peak value of displacement and acceleration of floor vibration is slightly reduced,and the response of Y-direction vibration to the thickness is relatively stable The higher the train speed is,the richer the vibration acceleration spectrum of the composite floor is,the larger the main frequency in three directions of the floor is,the amplitude of low frequency and high frequency increases correspondingly,and the high frequency part increases more obviously;the distance between trains has a significant filtering effect on the low frequency and high frequency components of the floor vibration,and the closer the structure is to the train,the higher the vibration acceleration of the floor is The high frequency component of dynamic response spectrum is more obvious.