Based on the upper bound theorem of limit analysis,the factor of safety for shallow tunnel in saturated soil is calculated in conjunction with the strength reduction technique.To analyze the influence of the pore pressure on the factor of safety for shallow tunnel,the power of pore pressure is regarded as a power of external force in the energy calculation.Using the rigid multiple-block failure mechanism,the objective function for the factor of safety is constructed and the optimal solutions are derived by employing the sequential quadratic programming.According to the results of optimization calculation,the factor of safety of shallow tunnel for different pore pressure coefficients and variational groundwater tables are obtained.The parameter analysis shows that the pore pressure coefficient and the location of the groundwater table have significant influence on the factor of safety for shallow tunnel. Based on the upper bound theorem of limit analysis, the factor of safety for shallow tunnel in saturated soil is calculated in conjunction with the strength reduction technique. Analyze the influence of the pore pressure on the factor of safety for shallow tunnel, the power of pore pressure is considered as a power of external force in the energy calculation. Using the rigid multiple-block failure mechanism, the objective function for the factor of safety is constructed and the optimal solutions are derived by employing the sequential quadratic programming. According to the results of optimization calculation, the factor of safety of shallow tunnel for different pore pressure coefficients and variational groundwater tables are obtained. the parameter analysis shows that the pore pressure coefficient and the location of the groundwater table have significant influence on the factor of safety for shallow tunnel.