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Stability Analysis of the Surrounding Rock of Large-Span Multi-Arch Tunnels Based on the Hoek-Brown Criterion
Abstract Compared with the Mohr-Coulomb strength criterion, the Hoek-Brown strength criterion comprehensively considers more influential factors such as the characteristics of the rock structure surface, rock mass strength, and the deterioration of rock parameters caused by construction disturbances. It can also reflect the nonlinear failure characteristics more accurately, thereby facilitating rock engineering practice much better. Based on numerical simulation, the geology strength index (GSI ), the empirical constant of the rock (mi), the factor of construction disturbance (D,) and the uniaxial compressive strength of the rock (σci) were analyzed to explore the influence on surrounding rock stability. Conclusions can be drawn as follows: GSI is a highly sensitivity parameter, and its value is directly related to the accuracy of the analysis results; mi is greatly impacted by GSI , and mi is not a sensitive factor if GSI is greater than 30; and the relationship between the construction disturbance factor D and vault settlement is parabolic when the rock is weak, and tends toward a linear relationship with improvement of the rock mass quality. The measures for maintaining rock stability during construction are ultimately discussed.
Abstract：
Compared with the Mohr-Coulomb strength criterion, the Hoek-Brown strength criterion comprehensively considers more influential factors such as the characteristics of the rock structure surface, rock mass strength, and the deterioration of rock parameters caused by construction disturbances. It can also reflect the nonlinear failure characteristics more accurately, thereby facilitating rock engineering practice much better. Based on numerical simulation, the geology strength index (GSI ), the empirical constant of the rock (mi), the factor of construction disturbance (D,) and the uniaxial compressive strength of the rock (σci) were analyzed to explore the influence on surrounding rock stability. Conclusions can be drawn as follows: GSI is a highly sensitivity parameter, and its value is directly related to the accuracy of the analysis results; mi is greatly impacted by GSI , and mi is not a sensitive factor if GSI is greater than 30; and the relationship between the construction disturbance factor D and vault settlement is parabolic when the rock is weak, and tends toward a linear relationship with improvement of the rock mass quality. The measures for maintaining rock stability during construction are ultimately discussed.
.Stability Analysis of the Surrounding Rock of Large-Span Multi-Arch Tunnels Based on the Hoek-Brown Criterion[J] MODERN TUNNELLING TECHNOLOGY, 2013,V50(6): 94-100
2013, Vol. 50 