The Vibration Propagation Characteristics By The Small Vehicle Crossing Speed Bumps

In recent years, with the increasing importance of road traffic safety in our country, all kinds of road deceleration facilities has been widely applied. Speed bump as one of the effective speed road deceleration facilities, its application rate is extremely high. However, things often there are always two sides to everything, although speed bumps improve the safety of traffic, but the vibration caused by the vehicle through the speed bump has a great impact on the surrounding environment. Therefore, it is of great theoretical and practical significance to explore the propagation and attenuation characteristics of ground vibration caused by the vehicle through the speed bump.First of all, starting from the definition of speed bumps, elaborated the domestic several common speed bump with the advantages and disadvantages and applicable occasions. From the theoretical analysis of the vehicles through speed bump caused by two main processes of ground vibration, wheel decelerating impact zone and the vehicle hit the ground. at the same time, analysis the vibration propagation forms in soil and sums up the domestic and foreign to the ground vibration attenuation prediction formula.Secondly, first through the field experiment test analysis the vibration of surrounding environment differences when the vehicle passes through the speed bump, and clearly the main direction of propagation of vibration, the speed bump in front of the lateral ground. Then, select the vehicle velocity, road surface material, vehicle load and speed bumps and so on four main influencing factors to conduct a comprehensive test and data acquisition. At the same time, to determine the peak to the trough of the vibration acceleration extremum and vibration acceleration as the time domain and frequency domain analysis indicators respectively.Finally, in the time domain signal, through numerical analysis detailed study of the driving speed, road surface materials, vehicle load and speed humps materials etc four main factors for ground vibration transmission and vibration damping degree of influence. In the frequency domain signal, for each test point the main vibration frequency range and the peak acceleration of statistical analysis. The results showed that the vibration frequency of the vehicle through the cement pavement with steel deceleration is caused by the high-frequency range of 750-1950 Hz. When fully loaded vehicle by rubber cement pavement and vehicle with no load through speed bumps with asphalt pavement, we have had low and high frequency two main vibration frequency band and high frequency vibration acceleration peak decay rapidly in the distance. In the rest of the program, the vehicles through speed bumps cause vibration frequency for low frequency vibration within 0～70 Hz. In short, in the vehicle through speed bumps caused by the peak acceleration of vibration frequency on the attenuation with increasing distance are the source. Meanwhile, puts forward a model is Ar=a(?)-blg(1+r) to predict environmental vibration is caused by the vehicle through speed bumps, and use nonlinear regression methods, combined with the measured data to calculate the environmental vibration attenuation coefficient in the regression formula of optimal values of a and b.