Evaluation of the ultimate bearing capacity of a reinforced concrete slab of a pedestrian bridge with stiff rebars is a relevant issue investigated in the article. Dynamic analysis takes account of low velocities of dynamic loading. A 3D model of a structure is made. A stiff rebar is a U-shaped perforated profile welded to the plate. The focus of the computation methodology is the model verification. Towards this end, mechanical characteristics of materials are experimentally identified; full-size specimens are made and subjected to static load testing. The numerical study focuses on analyzing two sessions of loading by an impactor located in the center of a span. The impactor has symmetrical and nonsymmetrical impact spots. Dynamic loading is proposed to be simulated in several stages. At the final stage, the structure vibrates together with the impactor. The Menétrey–Willam model is chosen to describe the deformation of concrete; the stress-strain state of the structure and stiff rebars is described by a curvilinear diagram that conveys strengthening and shows the actual behavior of the rebars. An implicit integration scheme is employed to identify detailed dependences showing the time-dependent change in the stress-strain state components affecting structural safety. The conclusion is that nonsymmetrical loading is the most substantial dynamic effect, and stiff rebars can greatly increase the survivability of the system subjected to impacts of man-induced origin.