A two dimensional visco-plastic finite element model capable of handling the multistep excavaton was developed for investigating the effect of excavation-support sequences on the behaviour of underground openings in the jointed rock mass. Ubiquitous joint pattern was considered in the model and joint properties in each set were assumed to be identical. Passive, fully-grouted rockbolts were considered in the model. Visco-plastic deformations of joints and rockbolts were assumed to be governed by Mohr-Coulomb and von Mises yield criteria, respectively. With the ability of removing elements, the model can von Mises yield criteria, respectively. With the ability of removing elements, the model can simulate the multi-step excavation-support sequences. The reliability of the model to the stability analysis for the underground excavation in practice was checked by simulating the behavior of underground crude oil storage caverns under construction.