In order to choose rock cover of Xiamen subsea tunnel now
3D elastoplastic constitutive relation and damage evolution equation for 4 profiles has been done along the longitudinal of the tunnel. The numerical results of stress distribution
displacements
plastic zones and damage zones of rock mass after excavation are got. By means of analysis of stress disturbed area
and comparing rock cover of weak regolith with stress disturbed area at axis and raising or decreasing
it is easy to determine minimal rock cover; similarly
it is satisfying to evaluate stability from the numerical results of stress distribution
displacements
plastic zones and damage zones of rock mass after excavation. Thus
it can be concluded that the tunnel is stable even the rock cover of the subsea tunnel decrease 4m compare to the original design elevation by organic integration of the two.