Abstract In order to reveal the variation pattern of the surrounding rock bearing arch of deep-buried tunnel after excavation, the mechanical model for load-bearing ring is used to derive the analytical solution of the internal and external boundaries of the surrounding rock bearing arch of deep tunnel, and the finite difference software is used to analyze and investigate the variation pattern of the surrounding rock bearing arch of deep-buried tunnel under different surrounding rock grades, different buried depths and different lateral pressure coefficients and the coupling effect of the influencing factors. As the results indicate: The ranking of the factors in terms of their influence on the surrounding rock bearing arch of deep tunnel is surrounding rock grade> buried depth of tunnel> lateral pressure coefficient; the surrounding rock grade will directly determine the scope of the bearing arch, i.e. worse surrounding rock conditions will bring greater scope of stress redistribution induced by tunnel excavation; the scope of bearing area is largely in linear relation with the buried depth of tunnel, because as the buried depth increases, both internal and external boundaries of the bearing arch will shift toward the deeper part of the surrounding rock; lateral pressure coefficient imposes the greatest influence on the form variation of the bearing arch, where the morphological characteristics of the internal and external boundaries exhibit different variation patterns as the lateral pressure coefficient changes.
Abstract：
In order to reveal the variation pattern of the surrounding rock bearing arch of deep-buried tunnel after excavation, the mechanical model for load-bearing ring is used to derive the analytical solution of the internal and external boundaries of the surrounding rock bearing arch of deep tunnel, and the finite difference software is used to analyze and investigate the variation pattern of the surrounding rock bearing arch of deep-buried tunnel under different surrounding rock grades, different buried depths and different lateral pressure coefficients and the coupling effect of the influencing factors. As the results indicate: The ranking of the factors in terms of their influence on the surrounding rock bearing arch of deep tunnel is surrounding rock grade> buried depth of tunnel> lateral pressure coefficient; the surrounding rock grade will directly determine the scope of the bearing arch, i.e. worse surrounding rock conditions will bring greater scope of stress redistribution induced by tunnel excavation; the scope of bearing area is largely in linear relation with the buried depth of tunnel, because as the buried depth increases, both internal and external boundaries of the bearing arch will shift toward the deeper part of the surrounding rock; lateral pressure coefficient imposes the greatest influence on the form variation of the bearing arch, where the morphological characteristics of the internal and external boundaries exhibit different variation patterns as the lateral pressure coefficient changes.
PAN Tong1 ZHANG Junru1 DAI Yi1 CHEN Pengtao1 MA Kaimeng1,
2
.Variation Pattern of Surrounding Rock Bearing Arch of Deep Tunnel and Analysis on Its Impact[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(3): 72-84
2024, Vol. 61 