Stress redistribution and ground arch development during tunneling

Three-dimensional stress adjustment caused by tunneling is related with ground arching development. Investigating the development of ground arching by stress redistribution during tunneling is presented. A three-dimensional numerical simulation model was developed to gain understanding of adjustment of tunneling stress. Vertical stress adjustments σZZ above the tunnel roof during tunneling are analyzed, using four different cover depths H and four lateral pressure coefficients K. Shift of the inflection points of σZZ-depth curves above the tunnel roof during tunneling can be a reliable index to show the development of ground arching.