Abstract：Based on the discontinuous barrier theory for near-field waves, a new type of vibration mitigation track, called a row-layout cavity-ballastless track (RLCBLT), is proposed and its mitigation principle and performance are analyzed. First, shear waves with horizontal displacement were used to investigate the barrier vibration isolation and analytical solutions of the scattering effects of a single hole. Then, formulations of the diffraction wave field of a hole group were derived. The barrier can scatter the vibration energy and enlarge the geometric damping of the incident wave, thus providing the possibility of superposing and reducing the incident and scattering waves. RLCBLT can cause a diffraction effect that reduces the vibration energy in the area behind the barrier. Next, a track-tunnel-soil three-dimensional dynamic-finite-element model was established to calculate and compare the dynamic responses at the wall of a circular tunnel and at the ground surface under two conditions: a single line RLCBLT and a regular track. Under these two conditions, the profiles of the accelerations in the time domain, the frequency domain, and the one-third octave band are similar. Above 20 Hz, the acceleration level under the RLCBLT condition is slightly lower than that under the regular track condition, with the maximum difference appearing at 50 Hz. The insertion loss of the receiver point at the tunnel wall and at the ground surface is positive above 20 Hz, with the insertion loss of the former bring lower than that of the latter. The characteristics of the track system are not altered by the application of RLCBLT, and its vibration mitigation effect is more obvious above 50 Hz. RLCBLT can better mitigate train-induced vibrations beyond a certain distance from a barrier.
孙晓静 刘博 徐利辉. 基于近波场非连续屏障理论的孔列道床减振性能分析[J]. 土木工程学报, 2021, 54(S): 97-103.
Sun Xiaojing Liu Bo Xu Lihui. Vibration mitigation performance analysis of a row-layout cavity-ballastless track based on the discontinuous barrier theory. 土木工程学报, 2021, 54(S): 97-103.
