Unfavorable Geology and Mitigation Measures for Water Inrush Hazard during Subsea Tunnel Construction: A Global Review

Abstract

Water inrush hazard seriously threatens construction safety of subsea tunnels in unfavorable geological areas. In recent years, a large number of subsea tunnels have been built worldwide, some of which have experienced many water inrush disasters, especially in Japan and Norway. In this paper, a systematic methodology is proposed to rigorously review the current literature about water inrush in subsea tunnels. Emphasis is placed on recorded causes and evolution processes of water inrush, as well as relevant mitigation measures. In particular, the geological conditions that generate such water inrush hazards are initially discussed by counting cases of tunnel water inrush in the past decades (43 cases of water inrush hazards in tunnels (including mountain tunnels)). The process of formation of failure modes of water inrush, and the corresponding research methods (including theoretical, numerical and experimental) are reviewed, and can be used to pave the ways for hazard prevention and future research. This is followed by a summary of the prevention methods and mitigation measures used in practice, and a short discussion of the achievements and limitations of each method. Then combined with the evolution characteristics of the failure area, the water inrush process of different modes is divided into three stages, with a proposed a grouting scheme for each stage. Finally, concluding remarks, current research gaps and future research directions on subsea tunnel water inrush are provided and discussed.

An Integrated Method for Tunnel Health Monitoring Data Analysis and Early Warning: Savitzky–Golay Smoothing and Wavelet Transform Denoising Processing

“…relevant literature [30,31,[33][34][35], we used an enumeration method to list every combination of parameters to smooth the data. We take some combination of parameters with Win_len (3-11, must be odd), Orders (1-5), and Delta (1)(2)(3)(4)(5). SNR and RMSE are used to evaluate the smoothing effect.…”

“…In recent years, highway tunnel diseases have become increasingly prominent, especially in tunnels with serious adverse geological locations, significant structural damage, mechanical fractures [1,2], or hidden dangers, which are prone to bridge breaks, tunnel collapse, mudslides, and other accidents [3][4][5]. These accidents can cause substantial economic and life losses.…”

Effect of Constrictivity of Gel/Capillary Pores in Concrete on Chloride Ions Migration

“…Reinforced concrete (RC) lining is the most important supporting structure of subsea tunnels, and its durability is an important factor related to tunnel safety, operating costs, and service life (Qu et al, 2007). Compared to mountain tunnels, subsea tunnels are usually large high-risk projects due to the high water pressure and unlimited water recharge (Niu et al, 2022). Once the local damage to the subsea tunnel occurs, the huge amounts of unstoppable water gushing or bearing capacity loss of the lining structure of the subsea tunnel will lead to a large number of casualties inside the tunnel (Zhang et al, 2012), and even the whole tunnel would also be scrapped (Chen et al, 2022a), which is undoubtedly a terrible disaster.…”

Improving the Anti-washout Property of Acrylate Grouting Material by Bentonite: Its Characterization, Improving Mechanism, and Practical Application

“…They also have strong adaptability in both large-pore strata and small fissures, making them widely applicable in controlling groundwater leakage [7][8][9]. However, the acrylate grouting materials' weak resistance against dynamic water washout restricts their utility in tunnels in groundwater environments characterized by high flow velocity and water pressure [10,11].…”