Displacement Analytic Solution of a Deep Elliptical Tunnel in Transversely Isotropic Rock Mass

2011 ◽  
Vol 402 ◽  
pp. 593-597
Author(s):  
Zhi Zeng Zhang ◽  
Jin Hu Zhang ◽  
Dong Qi Hou ◽  
Xiao Peng Chen
Keyword(s):  
Rock Mass ◽  
Layered Structure ◽  
Transversely Isotropic ◽  
Mapping Method ◽  
Transversely Isotropic Rock ◽  
Variable Expression ◽  
Layered Rock ◽  
Transversely Isotropy ◽  
Isotropic Rock ◽  
Layered Rock Mass

Sedimentary rocks with layered structure account for two third of global land area, and this proportion is 77.3% in China, lots of metamorphic rocks also have significant features of layered structure, so there are a large number of stability problems about layered rock mass in mining engineering. Layered rock mass is generally considered to be transversely isotropic solid in mechanics. Based on the complex variable expression of displacement components of transversely isotropy, the displacement analytical solution of a deep elliptical tunnel in transversely isotropic rock mass is derived by conformal mapping method.

scholarly journals Optimization of Measuring Points Layout around a Tunnel in the Transversely Isotropic Rock Mass

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhizeng Zhang ◽  
Yongtao Li ◽  
Weili Yang ◽  
Shunchuan Wu ◽  
Xiaoli Liu ◽  
...  
Keyword(s):  
Rock Mass ◽  
Lateral Pressure ◽  
Back Analysis ◽  
Transversely Isotropic ◽  
Anisotropic Rock ◽  
Maximum Displacement ◽  
Transversely Isotropic Rock ◽  
Isotropic Rock ◽  
Anisotropic Rock Mass ◽  
Principle Of Maximum

The arrangement of measuring points has a great impact on the uniqueness and accuracy of the back analysis of displacement. To explore the arrangement method of measuring points in the anisotropic rock mass, the principle of maximum displacement is applied to study the optimization of measuring points layout around a tunnel in the transversely isotropic rock mass. Firstly, the criterion of maximum displacement is deduced. Secondly, the variations of displacement with angle and radius are analyzed, respectively, and two key lateral pressure coefficients are obtained. Thirdly, some principles of measuring points arrangement are summarized according to the criterion of maximum displacement. Finally, an example is given to prove the correctness of these principles. These principles can be used to guide the arrangement of displacement measuring points in the transversely isotropic rock mass, especially suitable for shaft excavation in horizontal sedimentary rock.

Model Test Study on Influences of Layered Rock Mass Dip Angle on Stability of Deep-Buried Tunnel

2011 ◽  
Vol 90-93 ◽  
pp. 2363-2371
Author(s):  
Bin Wei Xia ◽  
Ke Hu ◽  
Yi Yu Lu ◽  
Dan Li ◽  
Zu Yong Zhou
Keyword(s):  
Rock Mass ◽  
Physical Model ◽  
Model Test ◽  
Physical Models ◽  
Physical Model Test ◽  
Stress Distributions ◽  
Failure Characteristics ◽  
Layered Rock ◽  
Layered Rock Mass ◽  
Dip Angle

Physical models of layered rock mass with different dip angles are built by physical model test in accordance with the bias failure characteristics of surrounding rocks of layered rock mass in Gonghe Tunnel. Bias failure characteristics of surrounding rocks in thin-layered rock mass and influences of layered rock mass dip angle on stability of tunnel are studied. The research results show that failure characteristics of physical models generally coincide with those of surrounding rocks monitored from the tunnel site. The failure regions of surrounding rock perpendicular to the stratification planes are obviously larger than those parallel to. The stress distributions and failure characteristics in the surrounding rocks are similar to each physical model of different dip angles. The stress distributions and failure regions are all elliptic in shape, in which the major axis is in the direction perpendicular to the stratification planes while the minor axis is parallel to them. As a result, obvious bias failure of surrounding rocks has gradually formed. The physical model tests provide reliable basis for theoretical analysis on the failure mechanism of deep-buried layered rock mass.

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