In response to the challenges of detecting and forecasting adverse geological bodies and water inrush risks in long tunnels, this paper, based on the comprehensive analysis of seismic reflection waves and electroseismic effect coupling, has achieved a long-distance tunnel construction process, adverse geological detection, and early warning, and has realized precise forecasting of the scale and location of adverse water-containing bodies. Meanwhile, the transient electromagnetic theory and technology for detecting the position and scale of water-containing bodies have been proposed, achieving medium-distance water inrush risk detection. Finally, for water-containing bodies that are close, ground penetrating radar methods are used for detection and forecasting to achieve the purpose of close-range detection and forecasting. Ultimately, a comprehensive detection and forecasting theory and technology for adverse geological bodies and water inrush in long tunnels using electromagnetic, seismic wave, and electroseismic multi-means at long, medium, and short distances have been established. This technology has been applied to the detection and forecasting of adverse geology and water inrush in a tunnel in Fuzhou, and good application effects have been achieved through on-site excavation verification. By multi-means comprehensive forecasting technology and early warning systems, fine detection of adverse geology and water inrush during the tunnel construction process can be achieved, providing guidance and support for the safe construction of tunnels.
In deeply buried, small-clearance tunnels, the failure of the surrounding rock is profoundly influenced by the superposition of stresses and the cumulative disturbance effects from multiple blasting events. Consequently, the failure characteristics and mechanisms of the surrounding rock are highly complex. Through a comprehensive analysis encompassing failure investigations, geological assessments, and surrounding rock pressure monitoring, this study systematically examines the spatio-temporal failure characteristics and geological discrepancies across 3 parallel tunnels (namely, a pilot tunnel, a left tunnel, and a right tunnel). The analysis reveals the asymmetric failure behavior of the surrounding rock and offers a detailed discussion of the underlying mechanisms. The temporal and spatial evolution of the surrounding rock pressure in these tunnels is carefully analyzed, with an emphasis on uncovering the asymmetric failure mechanisms during the excavation of deep, small-clearance tunnels. The results demonstrate that the failure of the surrounding rock exhibits significant asymmetry during excavation, with the damage being more pronounced on the valley side compared to the mountain side. Furthermore, the degree of damage in the advance tunnel is substantially greater than that in the backward tunnel, particularly in sections following the excavation of the backward tunnel. Additionally, the distribution of the surrounding rock pressure in the advance tunnel also exhibits pronounced asymmetry. The asymmetric failure of the surrounding rock is primarily attributed to the stress concentration in the deep valley and the disturbances introduced by the excavation process, which induces tangential stress concentrations in the surrounding rock mass. The findings of this study hold considerable significance for the design and optimization of tunnel support systems, as well as for disaster prevention strategies in deeply buried, small-clearance tunnels.