Abstract With the development of tunnel projects, problems related to the squeezing deformation of highway tunnels under asymmetrical loads are more prominent. In this paper, based on Rubinnat's solution for the plastic zone of a circular tunnel section and by means of rotating the direction of the maximum principal stress, an analytical formula for the radius of the plastic zone of surrounding rock around a non-circular portal of a deep buried tunnel section was derived by the complex variable function theory. Furthermore, referencing the analytical solution to the elastic-plastic displacement of a circular tunnel under an asymmetrical load and using the mapping function and transformation law, a calculation formula for the actual squeezing deformation of tunnel surrounding rock was deduced accordingly. The analysis indicates that the actual plastic zone distribution of a tunnel's surrounding rocks is related to the maximum principal stress and shape of the tunnel, and the actual distribution scope of the plastic zone of a tunnel's surrounding rocks can be obtained by analysis and calculation, which provides a reference for the design and construction of similar tunnels.
Abstract：
With the development of tunnel projects, problems related to the squeezing deformation of highway tunnels under asymmetrical loads are more prominent. In this paper, based on Rubinnat's solution for the plastic zone of a circular tunnel section and by means of rotating the direction of the maximum principal stress, an analytical formula for the radius of the plastic zone of surrounding rock around a non-circular portal of a deep buried tunnel section was derived by the complex variable function theory. Furthermore, referencing the analytical solution to the elastic-plastic displacement of a circular tunnel under an asymmetrical load and using the mapping function and transformation law, a calculation formula for the actual squeezing deformation of tunnel surrounding rock was deduced accordingly. The analysis indicates that the actual plastic zone distribution of a tunnel's surrounding rocks is related to the maximum principal stress and shape of the tunnel, and the actual distribution scope of the plastic zone of a tunnel's surrounding rocks can be obtained by analysis and calculation, which provides a reference for the design and construction of similar tunnels.
CHEN ,
CHAO ,
LI Tian-Bin etc
.Analytical Solution to the Squeezing Deformation of Highway Tunnels Under Asymmetrical Loads[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(5): 54-60
2015, Vol. 52 