Coupling Analysis and Management Framework of Subway Construction Risks Based on WBS-RBS and CRI

Subway construction risk characteristics are becoming increasingly complex amid continuous urban subway construction and dense, sensitive development along the routes. This study uses the Shenzhen Metro Line 27 construction project as the engineering background. The research combines systems engineering and multi-dimensional risk coupling perspectives. The study systematically identifies adverse engineering factors. It determines the characteristics of complex engineering risk scenarios. The research introduces construction functional units. It builds a three-level Work Breakdown Structure (WBS) system. The study establishes a Risk Breakdown Structure (RBS) system based on the 5M1E theory. The research intersects the WBS and RBS. This action builds a quantitative matrix for work package-risk type identification. Subsequently, the study builds a risk coupling network. The research introduces a coupled risk index model. This model quantitatively evaluates the risk coupling level of different processes in the network. Finally, the study constructs an integrated subway construction risk management framework based on the results of risk identification and coupling characteristic analysis. This framework includes organization, processes, tools, and models. The results indicate that eight core risk nodes—including isolated boulders/complex strata, instability of excavation retaining structures, and abnormal shield tunneling parameters—have a critical impact on the risk evolution of this project. The coupling risk indices for shield tunneling parameter control and prefabricated component hoisting are 8.19 and 8.06, respectively, making them critical control work packages along the entire line and requiring dedicated risk management. This research provides a reference for risk evaluation and refined management of subway projects in similar complex urban environments.