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Influence of the Tectonic Stress Field on Stress and Deformation Failure Characteristics of a Tunnel's Surrounding Rock
(1 School of Resources and Environment, North China University of Water Resources and Electric Power, Zhengzhou 450045; 2State Key Laboratory of Shield Machine and Boring Technology, Zhengzhou 450001)
Abstract Based on the measured geostress of a tunnel and FLAC3D software, stress and deformation failure characteristics of surrounding rock after tunnel excavation were simulated with or without consideration of tectonic stress. The results show that: 1) obvious changes to rock stress occur after tunnel excavation, with stress concentration occurring on the sidewall under no tectonic stress and on the top or bottom of the tunnel under tectonic stress, and the area and degree of the stress concentration under a tectonic stress are significantly greater than that under no tectonic stress; 2) the maximum displacement and influence depth occur on the top and bottom of the tunnel under no tectonic stress while they occur on the sidewall under tectonic stress; 3) the outer boundary of the deformation area is shaped like a vertical butterfly under no tectonic stress while it is shaped like a horizontal butterfly under tectonic stress; 4) the outer boundary of the shear strain increment area is approximately shaped like a vertical ellipse under no tectonic stress while it is shaped like a horizontal ellipse under tectonic stress. The research results have particular significance for the stability analysis and support design of deep buried tunnels in zones with tectonic stress.
Abstract：
Based on the measured geostress of a tunnel and FLAC3D software, stress and deformation failure characteristics of surrounding rock after tunnel excavation were simulated with or without consideration of tectonic stress. The results show that: 1) obvious changes to rock stress occur after tunnel excavation, with stress concentration occurring on the sidewall under no tectonic stress and on the top or bottom of the tunnel under tectonic stress, and the area and degree of the stress concentration under a tectonic stress are significantly greater than that under no tectonic stress; 2) the maximum displacement and influence depth occur on the top and bottom of the tunnel under no tectonic stress while they occur on the sidewall under tectonic stress; 3) the outer boundary of the deformation area is shaped like a vertical butterfly under no tectonic stress while it is shaped like a horizontal butterfly under tectonic stress; 4) the outer boundary of the shear strain increment area is approximately shaped like a vertical ellipse under no tectonic stress while it is shaped like a horizontal ellipse under tectonic stress. The research results have particular significance for the stability analysis and support design of deep buried tunnels in zones with tectonic stress.
.Influence of the Tectonic Stress Field on Stress and Deformation Failure Characteristics of a Tunnel's Surrounding Rock[J] MODERN TUNNELLING TECHNOLOGY, 2016,V53(2): 54-62
2016, Vol. 53 