Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and th...Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and the design steps of the plug's length are illustrated.During the progress to determine the plug's length,the equivalent plastic strain on the potential slip surface is assumed as the flag to tell the failure against sliding,and the plug stability is overall estimated from the plastic zone range and connectivity.展开更多
The paper first analyzes the failure mechanism and mode of tunnel according to model experiments and mechanical calculation and then discusses the deficiency of taking the limit value of displacement around the tunnel...The paper first analyzes the failure mechanism and mode of tunnel according to model experiments and mechanical calculation and then discusses the deficiency of taking the limit value of displacement around the tunnel and the size of the plastic zone of surrounding rock as the criterion of stability. So the writers put forward the idea that the safety factor of surrounding rock calculated through strength reduction FEM(finit element method) should be regarded as the criterion of stability,which has strict mechanical basis and unified standard and would not be influenced by other factors. The paper also studies the safety factors of tunnel surrounding rock (safety factors of shear and tension failure) and lining and some methods of designing and calculating tunnels. At last,the writers take the loess tunnel for instance and show the design and calculation results of two-lane railway tunnel.展开更多
Taizishang slope of Qingjiang Reservoir in Huibei is within the range of atomization rainfall. The authors created the finite element model with ANSYS 10.0 and used strength reduction FEM to calculate thesafety coeffi...Taizishang slope of Qingjiang Reservoir in Huibei is within the range of atomization rainfall. The authors created the finite element model with ANSYS 10.0 and used strength reduction FEM to calculate thesafety coefficient of the slope on conditions with no rain, and theatomization rainfall lasting for 0.2 hours and 0.4 hours. The results show that the atomization rainfall would decrease the stability of the slope, and with rainfalls increasing, the stability would reduce much more.展开更多
基金National Natural Science Foundation of China(No.50809051)
文摘Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and the design steps of the plug's length are illustrated.During the progress to determine the plug's length,the equivalent plastic strain on the potential slip surface is assumed as the flag to tell the failure against sliding,and the plug stability is overall estimated from the plastic zone range and connectivity.
基金This research was funded by the National Project"973"(GrantNo. 2010CB732100)NSF of Chongqing (Grant No. CSTC2009BC0002)
文摘The paper first analyzes the failure mechanism and mode of tunnel according to model experiments and mechanical calculation and then discusses the deficiency of taking the limit value of displacement around the tunnel and the size of the plastic zone of surrounding rock as the criterion of stability. So the writers put forward the idea that the safety factor of surrounding rock calculated through strength reduction FEM(finit element method) should be regarded as the criterion of stability,which has strict mechanical basis and unified standard and would not be influenced by other factors. The paper also studies the safety factors of tunnel surrounding rock (safety factors of shear and tension failure) and lining and some methods of designing and calculating tunnels. At last,the writers take the loess tunnel for instance and show the design and calculation results of two-lane railway tunnel.
文摘Taizishang slope of Qingjiang Reservoir in Huibei is within the range of atomization rainfall. The authors created the finite element model with ANSYS 10.0 and used strength reduction FEM to calculate thesafety coefficient of the slope on conditions with no rain, and theatomization rainfall lasting for 0.2 hours and 0.4 hours. The results show that the atomization rainfall would decrease the stability of the slope, and with rainfalls increasing, the stability would reduce much more.
