To investigate the influence of existing building load on the deformation and earth pressure of the ground in shallow tunneling, two-dimensional trap-door model tests and the corresponding numerical analyses are carried out. A stack of aluminum rods is used in the model tests. Shallow and pile foundations supporting an initial dead load are modeled in the laboratory tests and numerical analyses. For the sake of comparison the laboratory tests and numerical simulations for tunneling in the initially undisturbed ground condition (i.e., green field) are performed as well. In the finite element analyses, a recently developed elastoplastic constitutive model, named subloading tij model, is used. The observed and computed results for the ground with existing building load are compared with those for the green field condition.