CALCULATION OF THE LOAD-BEARING CAPACITY FOR ROOF TRUSSES ON THE LIRA-SAPR PC BASED ON THE RESULTS OF A POST-FIRE INSPECTION

The article presents a computational analysis of the modeling of a prefabricated reinforced concrete roof truss, taking into account the deterioration of the physico-mechanical properties of reinforced concrete: a decrease in the adhesion of reinforcement to concrete; a decrease in the modulus of elasticity and, as a result, the ability to resist deformation; a decrease in the strength and overall rigidity of the structure under fire as a result of fire. The stress-strain state of structures in the elastic formulation of problems under static load was studied Subject of research: numerical model of a precast reinforced concrete roof truss. Materials and methods: data for this article were obtained during the survey of precast reinforced concrete roof trusses. The LIRA-SAPR software package was used for the analysis. Results: as a result of the computational analysis, mosaics of nodal displacements of the calculated reinforcement for elements were obtained taking into account damage after fire exposure. Conclusions: the bearing capacity of the reinforced concrete roof truss was calculated taking into account damage and changes in the properties of concrete and reinforcement after fire exposure by using the LIRA-SAPR software package and the requirements of SP 468.1325800.2019, recommendations for the reinforcement were developed.