Study On The Dynamic Characteristics And Vibration Serviceability For A Long-span Floor Under Vehicle Randomly Loads

The long-span pre-stressed reinforced concrete structures have many advantages such as flexible space layout and wide space, so these structures are widely applied on public buildings such as passenger stations. The disadvantages such as great flexibility, small damping, low frequency are obviously. The structure may vibrate under vehicle loads and pedestrian traffic. The study on dynamic characteristics and vibration serviceability is necessary.The dynamic characteristics of a long-span prestressed reinforced concrete floor from Ruian passenger station under random loads are analyzed through numerical analysis and field test, which including characteristics such as frequencies and peak accelerations. The result of engineering test is compared with those of ANSYS, the vibration serviceability of Ruian passenger station is evaluated. The main work is follows:(1)Evaluation standards of vibration serviceability at different time are collected at home and abroad. A new evaluation method based on the Annoyance Rate is used as the standard to evaluate the passenger station.Freguency weighted root mean square acceletation is used as evalution index. Finally, we got the annoyance rate curves under different situations and evaluate the comfortableness of Ruian passenger station.( 2) This paper presents a new method for analyzing vehicle dynamic load by the simulation analysis of random pavement roughness using inverse transformation on the basis of this stimulation through a quarter-vehicle model, by random vibration theory. Probabilistic dynamic load coefficient is proposed combined with engineering example and the probability distribution of vehicle peak dynamic load. The relationship between the dynamic load coefficient and the road level and vehicle velocity is studied.(3)The vibration serviceability of the long-span floor is studied with the results of modal analysis method and time history analysis method by the finite element analysis software ANSYS. The influence of different variables such as section sizes and diatances of main and secondary girders on structural dynamic characteristics.( 4) dynamic characteristics of the long-span floor of passenger station are measured. Different indexes such as peak acceleration and velocity are studied through the comparison of the results of dynamic test and finite element calculaition, acceleration response spectra are obtained at the same time, the vibration serviceability of Ruian passenger station is evaluated.