Aspects of Risk Analysis in the Micro-tunnelling Process

Despite its widespread use, micro-tunnelling is often perceived as a low-risk process, leading to a lack of comprehensive risk analysis and management. This chapter challenges this notion by examining the qualitative and quantitative risks inherent in micro-tunnelling, which are frequently overlooked in design and construction phases. It contrasts the prevalent reactive risk management strategy, which addresses issues post-occurrence, with a proactive approach that emphasizes pre-emptive measures such as feasibility studies and continuous monitoring. The chapter also underscores the significance of data management in achieving rational and economic operation of micro-tunnelling processes. It discusses the technical perception of risk, defining it as the product of consequence probability and associated costs, and explores how this understanding can influence risk management strategies. Furthermore, it identifies key risk aspects in micro-tunnelling construction, including geological uncertainties, obstacle presence, and the impact of perceiving pipes as mere transport objects rather than structural elements. The chapter also touches on practical risk mitigation strategies, highlighting the often-neglected phenomena of settlement and buoyancy, and the consequences of avoiding intermediate stations. It concludes by emphasizing the importance of advanced statistical algorithms and risk analysis in modern risk management, positioning micro-tunnelling as a model example of risk analysis and management in dynamic processes.