Application of comprehensive prediction method of water inrush hazards induced by unfavourable geological body in high risk karst tunnel: a case study

Abstract

While tunnelling in karst terrains, karst fissure water may endanger the safety of tunnel engineering and cause geological disasters such as water inrush. To ensure the safety of tunnel construction, in investigation stage, engineering geological and hydrogeological conditions of Jigongling Tunnel was analysed firstly. In design stage, a reasonable prediction method combining with optimization principle was selected to calculate the water inflow according to the geological and hydrogeological conditions analysed in the investigation stage. Then the advanced geological prediction was divided into different classes based on the water inflow. To make an accurate prediction, tunnel seismic prediction method, transient electromagnetic method, induced polarization method and advanced geological drilling were comprehensively applied in construction stage. This method combined with geology analysis, water inflow calculation and classification of advanced geological prediction is successfully applied in the Jigongling Tunnel of Fanba Expressway, and has provided a reference for the similar engineering constructions.

Risk assessment of water inrush in tunnel through water-rich fault based on AHP-Cloud model

“…The storage condition of groundwater determines the material source of water inrush (Shi et al 2017;Xu et al 2018). As faults and karsts are filled with water, water inrush disaster is likely to occur in tunnels through water-rich fault.…”

Risk Control Technology for Water Inrush during the Construction of Deep, Long Tunnels

“…Strata. According to formula (21), the parameters affecting the stability of waterproof strata are tunnel radius R, thickness d of waterproof strata, and wall rock unit weight c. By analysing the relationship between the parameters and the structural stability of waterproof strata, especially finding the factors having the greatest influence on structural stability, we provide guidance for strengthening the structure of the waterproof strata and reducing the risk of water inrush: because of the large number of parameters, when analysing the relationship between a certain parameter and safety factor, based on the geological information of the research project object, other parameters are selected as follows: c � 24 kN/m 3 , c t � 1.2 MPa, φ t � 34°, P � 8 MPa, d � 3 m, and H � 600 m.…”

“…Li et al [18,19] established a risk assessment model for tunnel water inrush based on attribute measures, and then Hao et al [20] developed the corresponding improved model. In response to the prevention and control of karst fissure water inrush disasters, Shi et al [21] proposed a water inrush risk prediction model based on geological analysis and water inrush volume prediction. rough the construction of their water inrush risk assessment model, a comprehensive understanding and mastery of the factors influencing water inrush risk were reached.…”

Risk assessment of water inrush caused by karst cave in tunnels based on reliability and GA-BP neural network

“…Typical karst structures are mainly divided into three types, large karst cave, karst fault and dissolution fissure, which are the main difficulties in tunnel construction (Bukowski 2011). Once large-scale water and mud inrush is triggered, it will lead to delayed construction period, increased cost, casualties and other incalculable disaster consequences (Li et al 2015;Shi et al 2017). According to the previous engineering cases, the water inrush disaster caused by karst cave accounted for the largest proportion.…”