Analysis of Three-Dimensional Vibration Characteristics of Single-Circle Double-Track Subway Tunnel under Moving Load

Mengying Yang,Chunquan Dai,Quanlei Wang,Jaime Gallardo Alvarado,Kun Jiang,Tingzhi Yang

doi:10.1155/2021/6620301

Abstract

With the development of urban rail transit, subway lines are becoming more and more denser, the departure time interval is short, and the probability of subway trains meeting is high. The impact of vibration caused by double-line subway meeting on the surrounding environment cannot be ignored. Taking the typical cross-section of a single-circle double-track subway tunnel as an example, a single running scenario and three typical meeting scenarios, namely, 4 s meeting, 6 s meeting, and 8 s meeting scenarios were considered, and a track-tunnel-foundation three-dimensional ABAQUS finite element model was established. The dynamic response of monitoring points at different distances between the center of the track bed and the center line of the track was analyzed. Results showed that due to the consistent load action period, the center acceleration of the track bed increases significantly during the meeting, the main frequency of vibration and the peak value of the 1/3 octave spectrum were increased by about 5 Hz, and the vibration level at the dominant frequency was increased by about 7 dB. The center displacement of the track bed and the peak compressive strain increased significantly under the 4 s meeting and 6 s meeting working scenarios; while the 8 s meeting and 4 s single running scenarios were basically the same, only the action time was doubled. The dynamic response of the 4 working scenarios decreases with the increase of distance, and the attenuation rate gradually decreases and has gradually stabilized within 15–19 m above the vault.

Highlights

With the acceleration of China’s urbanization process, the problem of traffic congestion has become increasingly prominent
Compared with single-hole single-track tunnels, single-hole double-track tunnels will encounter meeting scenarios, with greater dynamic load and longer acting time. erefore, it is of great engineering significance to study the vibration characteristics of single-hole double-track tunnel
Ren et al [1] and Lei et al [2] studied the dynamic response of subway tunnels in saturated soft soil and semiinfinite elastic space caused by subway moving loads by using analytical solutions and 2.5-dimensional finite element methods, respectively

Summary

Introduction

With the acceleration of China’s urbanization process, the problem of traffic congestion has become increasingly prominent. Lei et al [8] used ABAQUS to establish a three-dimensional dynamic finite element model and numerically simulated the settlement of soft soil foundation under subway train load. Because the initial meeting positions of the up and down trains are not fixed, for a given cross-section, there are multiple combinations of working scenarios for the given crosssection under the load of the double-track train On this basis, Pan et al [12] used PLAXIS finite element software to establish a plane finite element model, considering single running scenarios and three typical vehicle crossing scenarios, and analyzed the dynamic response of a single-circle double-track tunnel. Based on the ABAQUS finite element calculation program, this paper establishes a subway train double-track tunnel-foundation model. As the up and down trains are running at the same time, multiple combinations of load scenarios may appear at the control section of a single-hole double-track subway tunnel. Point A is the center point of the track bed, and point F is the monitoring point on the surface directly above a1 P11 P12

A Tunnel

Model Validation

Environmental Vibration Response Analysis