The article presents numerous studies of strengthening variants for the prefabricated reinforced concrete girth rail of trapezoidal cross-section by means of software package “LIRA SAPR”. The considered girth rail was found during a technical inspection of the responsible load-bearing structures of a five-storey garage building. It is in an emergency technical condition and requires measures to strengthen it. The authors propose the three most rational strengthening schemes and performed their comparative analysis of the effectiveness of increasing the load-bearing capacity. The calculated analysis of the most dangerous sections of the reinforced concrete construction of the girth rail is performed in the module “Section Designer” according to the method of nonlinear deformation model considering the nonlinear operation of concrete and reinforcement.