Calculation method for a steel-reinforced concrete bridge span structure with material separation along the neutral axis

Abstract

Introduction. In steel-reinforced concrete spans, the strength of reinforced concrete is not fully used due to the twostage inclusion of the cross section in the work and the irrational distribution of materials in the section. To increase the efficiency of the materials used, it is proposed to combine the steel and reinforced concrete parts along the neutral axis of the cross section. With such a cross-section design, the steel will always be in the tension zone, and the concrete in the compression zone. It is possible to implement such a design by constructing a span in one stage from prefabricated steel-reinforced concrete blocks.Materials and methods. It is possible to implement the calculation method with the separation of the material along the neutral axis when organizing the installation of the span structure in one stage, assuming that the section of the span structure operates in the elastic stage and following the laws of structural mechanics. To cover the features of the calculation of split and continuous span structures, a cantilever-beam static scheme was adopted.Results. The presented results of analytical calculations make it possible to estimate the consumption of materials in the manufacture of the span. The steel consumption of the span under study is 6.12 t/lm, the reinforced concrete consumption is 6.54 m3/lm.Installation of the span. The installation of the span is described, considering the design features.Conclusions. The optimal static layout of the span structure has been determined. A method for calculating a steel-reinforced concrete span with material separation along the neutral axis has been developed. An analytical calculation was performed to select the geometric parameters of the cross sections of the span.