Effect of straight bolt corrosion on mechanical properties of shield tunnel under DC stray current

Abstract

The strength of straight bolt is an important index affected the mechanical properties of shield tunnel, at present most studies only focus on the effect of bolt corrosion on local structure performance under DC stray current, but the performance change of local structure cannot reflect the stiffness degradation of the whole ring tunnel structure. The purpose of the research is to study the influence mechanism of bolt corrosion on mechanical properties of shield tunnel under DC stray current. Combined with numerical and experimental analysis methods, the coupling calculation of electric, chemical and mechanical fields is realized based on the theory of electrochemical and structural mechanic, the deformation and internal force of shield tunnel contained corroded bolt are also presented. The major conclusions include: the effect of straight bolt corrosion on the deformation and internal force of shield tunnel understraightjointassembling is greater than that understaggered joint assembly. When the number of DC stray current input point is equal, the effect of bolt corrosion on tunnel deformation and internal force under current bilateral input mode is greater than unilateral input mode and hypotenuse input mode.