Elasto-Plasticity of Circular Tunnel Consioering Seepaye Field in the Construction Period

The circular tunnel is a common structure in civil engineering.It is assumed that all the influence factors surrounding circle tunnel are axially symmetrical,and interface of elastic and plastic regions is in surrounding rock.Applying Mohr-Coulomb yield criterion and principal of effective stress,the elasto-plastic stress analysis method is established considering the seepage field in construction period and corresponding analytical formula is also presented.Firstly,plastic radius are resolved through trial or iteration method.Secondly,external press of tunnel is obtained,Thirdly,the stress and displacement of circular tunnel and surrounding rock is gained.An example is analyzed based on this method.