104 / 2024-08-12 16:05:22

Evolutionary Characteristics and Influencing Factors of 3D Load-Bearing Zones in Large Section Tunnels（投稿期刊：International Journal for Multiscale Computational Engineering）

deep-buried tunnel; surrounding rock load-bearing zone; 3D morphology; evolution law

In tunnel engineering, the surrounding rock serves as both the source of load and the load-bearing structure, and its "structural" attribute is achieved through the "load-bearing zone" within the surrounding rock. Understanding the development pattern and 3D characteristics of the surrounding rock load-bearing zone is crucial for determining the timing and parameters of support and ensuring tunnel stability. Firstly, the 3D spatial effect of the load-bearing zone is determined by the stress release coefficient. Furthermore, numerical calculation methods are employed to analyze the 3D characteristics of the surrounding rock load-bearing zone, taking into account the influence of geological conditions and tunnel engineering conditions. The 3D characteristics of the tunnel load-bearing zone was obtained. The research findings indicate that: The 3D shape of the tunnel's load-bearing zone resembles a thick "bullet" shape. The intermediate principal stress affects the longitudinal dimension of the surrounding rock load-bearing zone, while the horizontal principal stress influences the cross-sectional shape of the load-bearing zone. As the tunnel span increases, the longitudinal dimension of the 3D "bullet" load-bearing zone becomes longer, and the proportion of the non-load-bearing area to the tunnel area increases. This results in greater instability of the surrounding rock and more unfavorable stress conditions in the vertical direction.