Research Into Seismic Performance Of Reinforced Concrete Frame Structure After Fire

Fire is one of the most destructive disasters for building structures, once a buildingcatches fire, it may endanger people’s lives and result in great economic losses. With theimprovement of construction technology and the increasingly heightening of buildings, if abuilding is subjected to a localized fire, demolition and reconstruction of the whole buildingwill harass the local residents and waste a lot of money, so the most economical choice islocally strengthening for the building. But before doing so, it’s important to size up the overallperformance of the burnt building,especially the seismic performance analysis of high-risebuildings in the seismic regions, which can provide more adequate theoretical basis forstrengthening design,and guarantee the safety of building after reinforcement.In recent years, on the basis of a large number of experiments, researchers have maderemarkable achievements in the awareness of the fire disaster for RC building structures. Interms of material performance, scholars have had a deep understanding of the thermodynamicand thermal performances of steel and concrete materials. In terms of structure members,through the finite element discretisation of the cross section or equivalent section method,scholars have summarized the computational formula of the bearing capacity of the membersafter fire. In terms of frame structures, due to the limitation of experimental conditions,experimental study on the overall framework after fire is still scarce, but mostly focused onthe scale ratio test and software simulation stage; the analysis of seismic performance of anoverall framework, is generally conducted by using a statistical formula to deal withcharacteristic parameters in the skeleton curve of section moment and curvature restoringforce after fire, and by using the truss model of the software for research.This paper makes a case study of a post-fire textile building in Xining, Qinghai province,mainly covering the following duties:1. The mechanical and thermal properties of reinforced concrete materials under or afterfire are expounded in detail.2. The two-dimensional heat conduction equation is composed by the use of differencemethod and in combination with the comparatively perfect theory of high temperature performance of reinforced concrete materials.3. The temperature field of the rectangle cross section components under the condition ofthe specified temperature is calculated by using the finite element software ABAQUS, incomparison with Assessment Standard of Existing Build Structures After Fire, in the standardheating curve and under the corresponding temperature condition, the accuracy of theprogram is verified, furthermore, the temperature field distribution of various beams andcolumn sections for the model in the standard heating curve under different temperatures iscalculated.4. Its bearing capacity after fire is analyzed by using the SAP2000software function ofsection designer, according to the analytical results of the temperature field, with each beamand column section added, the whole building model is eventually set up, analyses of theelastic and dynamic elastic-plastic time history are conduct respectively, the change in seismicperformance after fire is comparatively analyzed.