Seismic Performance Analysis Of Reinforced Concrete Frame Structure Teaching Building With Sloping Roof In High Intensity Area

The teaching building is a special building for teaching activities,with the characteristics of personnel concentration.If it is damaged by an earthquake,it will cause a lot of casualties;In addition,the teaching buildings are often used as emergency shelters and temporary command centers in earthquakes.The seismic damage of buildings in high-intensity earthquake area will be more serious,and the slope roof makes the frame structure bear complex force,so it is necessary to study the seismic performance of teaching buildings.The project of this teaching building is located in an area with seismic fortification intensity of 8 degrees and seismic acceleration of 0.2g.It belongs to the area with high intensity.Firstly,PKPM is used to design the structure of the teaching building of Tongguan Jincheng Primary School with sloping roof.Then,based on this,SAP2000 software is used to conduct elastoplastic time history analysis and nappe analysis on the structure to study its seismic performance.In addition,the elastic-plastic analysis models of the roof slopes of 0 degree,25 degree,40 degree and 50 degree were established to study the influence of the roof slope on the seismic performance of the structure.Finally,by adjusting the support mode at the lower end of the ladder,the effects of the cast-in-place stairs and sliding support stairs on the seismic performance of the frame structure are studied.Through comparative analysis,the following conclusions can be drawn:1.The length-width ratio of the teaching building is 4.625.Its length-width ratio is relatively large,and the structure’s bi-directional stiffness distribution is quite different.PKPM software was used to analyze the response spectrum of the structure,and the analysis results showed that the deformation parameters of the structure were less than the limit value of the code,which met the requirements of the seismic code.Based on the analysis results,the seismic design of the teaching building structure is carried out according to the "three levels".2.According to the results of the aseismic design of reinforcement by using SAP2000 software for structure elastic-plastic time history analysis and pushover analysis,the base shear,vertex displacement and displacement between structure layer structure,etc.The analysis results show that the plastic hinge distribution Liang Xian yield under severe earthquake frame,frame column will not yield,which can realize the seismic fortification goal is not "big".3.According to the results of nappe analysis,when the building roof slope is 25 degrees,the stress of the frame structure is reasonable.When the roof slope is 50 degrees,the bending moment of the roof frame column at the structural performance point increases by about 10 times.The roof frame beam is under tension or full-section compression at the mid-span of the roof frame beam,and the structure is in an unsafe state.It is recommended that the slope roof slope does not exceed 50 degrees.4.The cast-in-place stairs in frame structures are easy to cause abnormal distribution of vibration mode and torsion of vibration mode.The influence of stair members on earthquake action should be included in the seismic calculation of the structure.The frame column of stairwell produces abrupt change of internal force in the rest platform,and the ladder column should be strengthened.When the sliding support is set at the bottom of the ladder,the abrupt shear force of the ladder column is reduced by 40%compared with that of the cast-in-place staircase,which is beneficial to the seismic resistance of the structure.