Risk Assessment and Early-Warning System for High-Speed Railway during the Construction and Operation of Underpass Bridges

Abstract

Potential risk assessment and early-warning system are essentially important to ensure the safety of high-speed railway (HSR) bridges. This paper presents an in-depth methodology of this risk assessment and early warning. Firstly, the risk sources, occurrence probabilities, and hazard consequences were investigated by consulting specialists. For kernel-risk sources, such as excavation and dewater activities, finite-element models were established to evaluate the deformation of foundations and approach embankments in various conditions. Then, with combined quantitative and qualitative analysis, the as low as reasonably possible (ALARP) criterion was utilized to obtain the results of risk assessment. On the early-warning system, autoregressive integrated moving average (ARIMA) method was used to predict the continuous deformation and to analyze the kernel indices that may affect the railway operations. At last, the forewarning interval of each index that can be used in the construction monitoring was suggested. The proposed methods of risk assessment, settlement prediction, construction monitoring, and early-warning system have been successfully applied to the Cuiheng Road Underpass of the Beijing-Tianjin Intercity Railway and may be used in future similar projects. Practices have shown that these methods can effectively reduce risks, ensure structural safety, and maintain sustainable development.