|Abstract Field ev idence has show n that large??sca le and unstable discontinuous p lane s in the rock m ass surrounding tunne ls in r ich w a ter
reg ion a re probab ly g enerated after ex cav ation. The tunnel surro unding ro ck w as div ided into three zones, inc lud ing e lastic zone,
p lastic dam ag e zo ne and shear fracture zone for asse ssing the stab ility of the tunnel surro unding ro ck. B y lo cal hydro geo lo gy, the
stresse s of surro und ing rock o f Jinshazhou circular tunne lw a s ana lyzed and the stress so lutions on the elastic and plastic dam age zo nes
w ere obta ined by app ly ing the theo ries o f fluid??so lid co upling and e lasto??p la stic dam agem echanics. The shear fracture zone generated
by jo ints w as studied and its rang e w as determ ined by using M ohr??C oulom b streng th cr iterion. Fina lly, the co rrectness of the
theoretical resultsw as va lidated by com par ing the scopes of shear fracture zones calculated in this paper w ith tho se from litera ture.