Study On The Reinforcement Scheme Of Existing Frame Structure In The Seismic Fortification Intensity Enhancement Area

With the development of science and technology and the renewal of seismic research results,the level of seismic design and the requirement of seismic appraisal of buildings are gradually improved and perfected.Especially with the new generation of Zoning Map of China's Earthquake Motion Parameters(GB 18306-2015),the seismic fortification intensity of a large number of areas in our country has been improved compared with that before.The existing buildings in these areas have been improved according to the current national standards The seismic appraisal standard for buildings(GB 50023)clearly stipulates that the appraisal and reinforcement work should be carried out in accordance with the new fortification requirements.The main problem of existing building reinforcement in these areas is that the overall performance of the structure is insufficient,which is different from that of ordinary reinforcement and transformation,which mainly solves the problem of insufficient bearing capacity of local components.Therefore,it is necessary to study the reinforcement scheme of existing frame structure in the area with increased fortification intensity.Based on the concrete engineering example of seismic reinforcement of existing frame structures in the area of enhanced fortification intensity,this thesis firstly uses SETWE module of PKPM software to analyze the effect of increased fortification intensity on existing frame structures,compares and analyses the seismic control parameters of existing frame structures under four different fortification intensity,such as reinforcement usage,inter-story displacement and shear-weight ratio,and summarizes the effect of increased fortification intensity on existing frame structures.The influence of reinforcement and reconstruction.Then according to these influences and the results of the trial calculation of PKPM software,the reasonable reinforcement scheme of the existing frame in the area with enhanced fortification intensity is selected.Finally,the reinforcement scheme based on the change of structural system and the reinforcement method based on component is selected,and the selection principle of the reinforcement scheme of the frame structure in the area with enhanced fortification intensity is summarized.Finally,this thesis uses the Pushover analysis method based on SAP 2000 to analyze the seismic performance of structures under rare earthquakes.The comparative analysis results of Pushover curve,capacity demand spectrum,internal force state of frame members and plastic hinge development before and after reinforcement show that:(1)the vibration shape of the structure after reinforcement is not different from that of the original structure,but the structural period is obviously reduced,which indicates that the problem of insufficient structural stiffness has been greatly improved,but attention should also be paid to the reduction of effective period of the structure.The influence of near site period on the increase of seismic response.(2)The lateral displacement of the structure strengthened by the system has been effectively controlled,and the seismic performance of the structure under the action of frequent or rare earthquakes has been improved.(3)Compared with the original structure,the internal force of structural members has been effectively controlled after the reinforcement of the system,which significantly reduces the amount of reinforcement work.This thesis proves that the combination of system reinforcement and component reinforcement can effectively improve the seismic performance of the structure,and the amount of reinforcement work is effectively reduced,the economic effect is remarkable,which can provide reference and basis for the selection of reinforcement schemes of existing frame structures in the area of increased fortification intensity.