Response of high-speed railway tunnel-track system under strike-slip fault dislocation-Part 1: Model test design and implementation

Abstract

Conventional cross-fault tunnel model tests are limited by incomplete representation of shear deformation in fault zones, omission of internal track structures, reliance on traditional sensors, and large boundary dimensions that reduce geometric scaling, posing challenges for the design and safe operation of tunnels under fault dislocation. To address these issues, this study develops a repeatable large-scale physical modeling platform to investigate the mechanical response of high-speed railway tunnel-track systems under strike-slip fault dislocation. The test scheme, based on similarity theory and enhanced with three-dimensional laser scanning technology, ensures structural fidelity and high-precision, full-field measurement. Key aspects, including model box design, material selection, structural fabrication, and boundary effects verification, were systematically optimized. The physical model realistically incorporates tunnel lining, ballastless track, and surrounding rock, with displacement-controlled loading applied to simulate fault-induced deformation. Experimental results closely match field observations and numerical simulations, demonstrating the reliability of the platform. This study achieves methodological breakthroughs in system design, monitoring strategy, and boundary treatment, providing an effective and reproducible framework for understanding tunnel-track interactions, evaluating anti-fault measures, and optimizing the structural design of high-speed railway tunnels across complex fault zones.