Purpose The rapid expansion of high-speed railway (HSR) networks in Western China has increased the exposure of linear infrastructure to active faults. This study establishes and applies a probabilistic fault displacement hazard analysis (PFDHA) framework to quantify both on-fault surface rupture and distributed off-fault permanent ground deformation (PGD) hazards for HSR crossings of the Xiaojiang Fault Zone (XJFZ). Design/methodology/approach A PFDHA framework is developed, integrating a Poissonian seismicity model with spatial rupture randomness. The methodology is applied to the XJFZ, which crosses the Nanning-Kunming (NK) and Shanghai-Kunming (SK) HSR. Permanent displacement hazards are evaluated for 2 probability levels: 10% and 2% probability of exceedance in 50 years. Findings Through the evaluation of displacement hazards for 50-year exceedance probabilities of 10% and 2%, this study finds that for the NK and SK HSR, permanent displacements at a 10% probability of exceedance range from 1.0 m to 2.9 m, peaking at fault intersections. Comparative analysis shows that traditional deterministic estimates (1.3–2.0 m) generally align with the probabilistic results but fail to capture the full range of risk. Originality/value This work adapts PFDHA to linear infrastructure in a tectonically active region of China, explicitly considering both on- and off-fault displacement within engineering-relevant corridors. The integration of regional rupture scaling and segment-based constraints provides a reproducible basis for displacement hazard assessment in HSR planning and retrofit.
Jiahui Feng (Tue,) studied this question.