Analysis method and design charts for bolt reinforcement of the tunnel face in cohesive-frictional soils

2015 ◽  
Vol 47 ◽  
pp. 162-181 ◽  
Author(s):  
G. Anagnostou ◽  
P. Perazzelli
Keyword(s):  
Analysis Method ◽  
Tunnel Face ◽  
Design Charts ◽  
Bolt Reinforcement ◽  
Frictional Soils

scholarly journals Face Stability Analysis of Shield Tunnels in Homogeneous Soil Overlaid by Multilayered Cohesive-Frictional Soils

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Kaihang Han ◽  
Chengping Zhang ◽  
Wei Li ◽  
Caixia Guo
Keyword(s):  
Failure Mechanism ◽  
Shear Failure ◽  
Three Dimensional ◽  
Earth Pressure ◽  
Support Pressure ◽  
Tunnel Face ◽  
Arch Effect ◽  
Theory Approximation ◽  
Homogeneous Soil ◽  
Frictional Soils

In order to better interpret failure features of the failure of soil in front of tunnel face, a new three-dimensional failure mechanism is proposed to analyze the limit support pressure of the tunnel face in multilayered cohesive-frictional soils. The new failure mechanism is composed of two truncated cones that represent the shear failure band and a distributed force acting on the truncated cones that represents the pressure arch effect. By introducing the concept of Terzaghi earth pressure theory, approximation of limit support pressures is calculated using the limit analysis methods. Then the limit support pressures obtained from the new failure mechanism and the existing approaches are compared, which show that the results obtained from the new mechanism in this paper provide relatively satisfactory results.

Stability analysis model for a tunnel face reinforced with bolts and an umbrella arch in cohesive-frictional soils

2020 ◽  
Vol 124 ◽  
pp. 103635 ◽  
Author(s):  
Xiao Zhang ◽  
Mingnian Wang ◽  
Zhilong Wang ◽  
Jiawang Li ◽  
Siguang Zhao ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Analysis Model ◽  
Tunnel Face ◽  
Umbrella Arch ◽  
Frictional Soils

scholarly journals Rotational Failure Mechanism for Face Stability of Circular Shield Tunnels in Frictional Soils

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Yuan Zhou ◽  
Yuming Zhu ◽  
Shumao Wang ◽  
Hu Wang ◽  
Zhengxing Wang
Keyword(s):  
Failure Mechanism ◽  
Upper Bound ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Circular Cross Section ◽  
Support Pressure ◽  
Tunnel Face ◽  
Face Stability ◽  
Rotational Failure ◽  
Frictional Soils

Face stability analyses of shield-driven tunnels are often carried out to determine the required support pressure on the tunnel face. Although various three-dimensional mechanisms have been proposed for circular faces of tunnels in frictional and/or cohesive soils to obtain the limit support pressure, the most critical one has not yet been found. Based on a rotational failure mechanism for the frictional soils, this paper modifies the circular cross section as an ellipse to make the generating collapse surface inscribe the entire circular tunnel face. Using the kinematical approach of limit analysis yields an upper bound to the limit support pressure. Through comparisons with the existing results in the literature, the improved mechanism can better estimate the upper bound and is very similar to the observed failures in the experimental tests. The influences of the pore water pressure are also included in the stability analysis of tunnel faces. Calculated upper-bound solutions are presented in a condensed form of charts for convenient use in practice.

Safety factor analysis of a tunnel face with an unsupported span in cohesive-frictional soils

2020 ◽  
Vol 117 ◽  
pp. 103221 ◽  
Author(s):  
Xiao Zhang ◽  
Mingnian Wang ◽  
Jiawang Li ◽  
Zhilong Wang ◽  
Jianjun Tong ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Safety Factor ◽  
Tunnel Face ◽  
Frictional Soils
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