A multi-parameters assessment method and prediction model for ground vibration under the high-speed railway bridge.

In this work, through the field monitoring and vibration signal analysis, we proposed a multi-parameters vibration assessment method for ground vibration induced by high-speed railway trains. And also, based on the assessment results, we developed a prediction model of z-vibration level, which is characterized with multiple piers vibration source and exactly applicable to the ground vibration prediction under the high-speed railway bridges. Firstly, by carrying out the field monitoring test, the ground vibration signals induced by high-speed railway trains were collected, with the ground vibration characteristics and influencing factors under the high-speed railway bridge are analyzed. Secondly, the ground vibration assessment was conducted by Peak Particle Velocity (PPV), Peak Particle Acceleration(PPA) and the z-Vibration Level (VL) respectively, and on this basis, we proposed a multi-parameters vibration assessment method for ground vibration around the high-speed railways. Then, according to the assessment results, based on the vibration attenuation model under railway traffic load effect and the superposition feature of multi-piers vibration sources under high-speed railway bridges, we developed a ground vibration attenuation prediction model of VL, which is characterized with multi-piers vibration sources and exactly applicable to the ground vibration prediction under the high-speed railway bridges. Besides, an application example of environment vibration prediction was given, and the site selection distance threshold away from the high-speed railways of different types of environmental vibration function areas were determined. The study showed that the proposed multi-parameters vibration assessment method was so comprehensive that it could take the vibration safety of building structures, human perception comfort and environmental vibration limit all into consideration. And meanwhile, by comparing the predicted VL with the field monitored data and the empirical formula calculated value, the developed ground vibration attenuation prediction model was tested with better prediction accuracy and wider effective prediction range. As a result, the study was expected to provide a theoretical reference for the construction of ground vibration assessment system around high-speed railways, with potential engineering application value in ground vibration attenuation prediction and site selection of building structures under the high-speed railway bridges.