Numerical Analysis of Vibration Responses in High-Speed Railways considering Mud Pumping Defect

Abstract

As a newly appeared defect under slab tracks in high-speed railways, mud pumping weakens the support ability of the subgrade to slab track, bringing about deviations on the vibration responses of the vehicle, slab track, and subgrade. Therefore, this paper proposes a vehicle-slab track-subgrade coupled model based on the multibody simulation principle and the finite element theory to highlight the influences of mud pumping defect. As an external excitation to this model, random track irregularity is considered. In order to simulate the mud pumping defect, the contact between the concrete base and subgrade is described as a spring-damper system. This model is validated by field test results and other simulation results, and a very good agreement is found. The vibration responses of the vehicle, slab track, and subgrade under different mud pumping lengths and train speeds are studied firstly. The deviations of vibration responses in high-speed railways induced by mud pumping are then obtained, and the limited mud pumping length is put forward finally to provide a recommendation for maintenance works of high-speed railways in practice.

Identification of Temperature-Induced Deformation for HSR Slab Track Using Track Geometry Measurement Data

“…Compared with deterioration analysis and effect characterization of structural damages for slab track, less attention has been paid to the development of a sophisticated detection method of such deformation. Since Note: 1 The number of slabs that are detected as warped slabs based on geometry data; 2 The number of healthy slabs that are detected as warped slabs based on geometry data; 3 The number of warped slabs that are realized as healthy slabs based on geometry data.…”

“…Total Slabs Anomalies 1 False Alarms 2 Missed Alarms 3 Section I 6202 33 6 2 Section II 6201 61 12 4 Section III 6202 60 10 3 Section IV 6201 29 4 0 Total 24,806 183 32 9 Note : 1 The number of slabs that are detected as warped slabs based on geometry data; 2 The number of healthy slabs that are detected as warped slabs based on geometry data; 3 The number of warped slabs that are realized as healthy slabs based on geometry data.…”

“…The design of HSR slab track has been improved a lot since 1970s (earlier slab track systems constructed in Germany and Japan [1,2]), which made it successful in HSR applications, especially in Japan and China where the newly built lines include a high percentage (up to 96 %) of slab track [3]. Nevertheless, some problems inevitably occur in track substructures due to the coupling effect of the trainload and environmental actions [4][5][6][7].…”

“…To investigate how track slab damages initiate and how they affect vehicle-track system dynamics and track irregularities, previous studies carried out numerical simulations [3][4][5][6][7][8][10][11][12][13][14][15][16], full-scale tests [9,[17][18][19], and field tests [15,20,21]. These studies shed some light on repair works for defects, slab maintenance, and life-cycle management of slab track.…”

Saturated Ground Vibration Analysis Based on a Three-Dimensional Coupled Train-Track-Soil Interaction Model

“…By the end of 2018, the operating mileage of high-speed rail networks reached 29,000 km in China. These high-speed trains will impart higher dynamic forces in rail infrastructures and result in an elevated vibration level for the ground [4][5][6]. Hence the assessment of ground vibration becomes increasingly essential for the design, operation, and maintenance of railways in practice.…”