Tunnel and underground construction projects form the backbone of modern urban infrastructure, enabling sustainable transportation, utility networks, and subsurface development in growing cities worldwide. From metro systems and road tunnels to underground storage facilities and utility corridors, these complex engineering endeavors are essential for urban mobility, economic growth, and resilient city planning.
However, tunnel projects are notoriously prone to schedule delays and cost overruns. Geological uncertainties, groundwater challenges, technical complexities, equipment failures, regulatory hurdles, and logistical constraints often disrupt timelines, inflate budgets, and defer public benefits. In megaprojects involving tunnel boring machines (TBMs) or deep excavations, even minor delays can cascade into significant setbacks, affecting project viability, safety, and stakeholder confidence.
Effectively understanding and mitigating delays in tunnel and underground construction has become a priority for engineers, project managers, and decision-makers. By identifying recurring risk factors, adopting proactive planning approaches, and leveraging lessons from global projects, the industry can improve time performance, control costs, and enhance the successful delivery of essential subsurface infrastructure.
Below, we present a curated list of key research articles and studies addressing delay causes, risk analysis, and mitigation strategies in tunnel and underground construction. This collection aims to support professionals, researchers, and stakeholders in navigating the complexities of subsurface project delivery.