Dynamic optimization of support parameters and risk prevention and control during tunneling with fractured surrounding rock: a case study of the Gande’er Mountain tunnel project

As rock tunnel construction gradually progresses into the complex engineering stages characterized by long, large, deep, and challenging projects, evaluating the quality of surrounding rock and ensuring excavation safety become formidable tasks due to the intricate and variable geological conditions encountered during tunnel excavation. Precisely extracting the characteristics of rock structures and scientifically assessing tunnel stability have emerged as critical issues requiring urgent solutions. This study integrates computer aided engineering (CAE) with tunnel seismic tomography (TST) advanced geological prediction techniques to dynamically assess the quality of surrounding rock during tunnel construction. Additionally, it employs the discrete element method (3DEC) to dynamically simulate the excavation of various support methods in environments with fracture development. Research findings indicate that CAE technology can precisely reveal the dynamic changes in the rock integrity coefficient during tunnel excavation. TST technology provides advanced geological predictions for complex structures like weak interlayers and fracture zones within the rock mass to be excavated, thereby reducing the risk of failure in the surrounding rock caused by unfavorable geological formations. The numerical simulations based on 3DEC offer a scientific foundation for the safe and rapid construction of fractured rock tunnels and allow optimization of subsequent support proposals. This study suggests a viable construction approach addressing the potential risks in tunnel construction. This approach enables continuous monitoring of changes in the surrounding rock and provides a basis for adjusting excavation methods and optimizing support methods. The findings have significant practical implications for the construction of similar underground projects. A novel approach integrating CAE and TST technologies is proposed to dynamically evaluate the quality of complex fractured rock masses during tunnel construction and optimize support schemes. Numerical simulations confirm that the improved support design significantly enhances construction stability, reduces deformation risks, and minimizes support stress. This study presents a construction concept suitable for complex geological conditions, offering practical guidance for safe execution and cost control in similar projects.