Chapter 1 Advanced Laboratory Characterization of Railway Track Geomaterials 1.1 Constant confining pressure (CCP) triaxial tests 1.1.1 Traditional track materials 1.1.2 Nontraditional recycled track geomaterials 1.2 Variable confining pressure (VCP) triaxial tests Chapter 2 Modeling the Coupled High speed Train-ballasted Track-subgrade System 2.1 Deterministic model and analysis 2.2 Probabilistic model and analysis Chapter 3 Advanced Performance Monitoring and Evaluation Technologies of High speed Railway Track 3.1 Particle movement-based compaction quality evaluation 3.2 Materials tested 3.3 Vibratory plate compactor and loading parameters 3.4 Smart sensing technology for monitoring particle movement 3.4.1 SmartRock sensors 3.4.2 Processing workflow of particle motion data 3.4.3 Time-frequency analysis based on continuous wavelet transform (CWT) 3.4.4 The laboratory vibratory compaction test matrix 3.4.5 Results and discussions 3.4.6 Particle movement characteristics during different compaction stages 3.4.7 Particle movement characteristics in different positions 3.4.8 Effect of gradation on particle movement characteristics 3.4.9 Effect of vibratory frequency on particle movement characteristics 3.4.10 Effect of vibratory frequency on particle rotations 3.4.11 Effect of vibratory frequency on particle kinematic energy 3.4.12 Compaction quality assessment based on particle motion characteristics 3.4.13 Summary and conclusions 3.5 Particle movement based track defect evaluation 3.5.1 Introduction 3.5.2 Description of the transition zone studied 3.5.3 Field instrumentation plan for measuring dynamic responses 3.5.4 Dynamic parameters of track foundation 3.5.5 Test train 3.6 Dynamic responses of the subgrade bed in longitudinal direction 3.6.1 Time history data 3.6.2 Frequency-domain characteristics 3.6.3 Variation of dynamic response amplitudes along the longitudinal direction 3.7 Dynamic responses of the subgrade bed under different train speeds 3.7.1 Variation of dynamic stress amplitudes with train speed 3.7.2 Variation of dynamic displacement amplitudes with train speed 3.7.3 Variation of vibration characteristics with train speed 3.8 The influence of the train axle load 3.8.1 Time history data 3.8.2 Comparison of amplitudes of dynamic responses 3.8.3 Comparison of frequency spectrum data 3.9 Summary & conclusions Appendices References