Study of squeezing deformation and support characteristics of tunnels
Author(s): LIU Zhi-qiang, SONG Ye, HU Yuan-fang, China Railway Southwest Research Institute Co., Ltd.
Pages: 413-418
Year: 2013 Issue: S1
Journal: Rock and Soil Mechanics
Keyword: squeezing deformation; weak surrounding rock; high ground stress; yielding support;
Abstract: In light of the squeezing deformation problem,based on Muzhailing tunnel research and other relative data analysis,it is concluded that large value and long time deformation are the squeezing deformation characteristics,both sides are usually advantage location in the whole deformation of tunnel.Test data show that surrounding rock pressure,stress of steel arch centering,axial force of anchor have a larger value in rigid support,where stress of steel may exceed the yield strength of material;anchor is more effective on side walls than other position;surrounding rock pressure and deformation increment is inversely proportional.The results show that rock pressure can be reduced by control release of surrounding rock deformation,is beneficial to the long-term stability of the tunnel structure.Yielding support is proposed,and reserved deformation can be predicted preliminarily.Numerical calculation shows that large enough stiffness is required for rigid support to control displacement in a small range,Yielding support has advantages in control deformation and reduces stress of steel;it is a better control technology in squeezing deformation tunnels.
Pages: 413-418
Year: 2013 Issue: S1
Journal: Rock and Soil Mechanics
Keyword: squeezing deformation; weak surrounding rock; high ground stress; yielding support;
Abstract: In light of the squeezing deformation problem,based on Muzhailing tunnel research and other relative data analysis,it is concluded that large value and long time deformation are the squeezing deformation characteristics,both sides are usually advantage location in the whole deformation of tunnel.Test data show that surrounding rock pressure,stress of steel arch centering,axial force of anchor have a larger value in rigid support,where stress of steel may exceed the yield strength of material;anchor is more effective on side walls than other position;surrounding rock pressure and deformation increment is inversely proportional.The results show that rock pressure can be reduced by control release of surrounding rock deformation,is beneficial to the long-term stability of the tunnel structure.Yielding support is proposed,and reserved deformation can be predicted preliminarily.Numerical calculation shows that large enough stiffness is required for rigid support to control displacement in a small range,Yielding support has advantages in control deformation and reduces stress of steel;it is a better control technology in squeezing deformation tunnels.
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