Abstract：Firstly the momentum equilibrium equation，the continuity equation for water are established. Secondly by using the Galerkin method all the governing equations are discredited in the space domain and in the time domain respectively，thirdly a two dimensional FEM code for coupled hydro-mechanical elastic analysis of saturated porous medium is developed tentatively. Then the computations of the effects of rock bolting for an underground opening located under water table，in which the rock mass is assumed to be saturate，are given. For the cases without water and with water (the seepage coefficient K are constants and the functions of the normal stresses respectively)，the elastic analyses are carried out by using the developed FEM code. After investigating the distribution states of the displacements and the pore pressures in the rock mass，it is known：under the condition of groundwater existing，(1) the main action of rock bolting is also limiting the displacements of surrounding rock mass but the action becomes weaker compared with the case without groundwater，(2) rock bolting does not have obvious restraining effect for percolation，(3) the determining patterns of permeability values will greatly influence the distributions of pore pressures in rock mass.
