Analysis On The Effect Of Structural Stiffness And Longitudinal Seismic Performance Of A Modification In The Single Story Industrial Building

In recent years, with the continuous development of China’s construction industry, a growing number of buildings need to be reinforced and renovated to meet the growing needs of owners, construction industry is into a new period that new projects construction and building maintenance and modification coexists. It is of particular importance to modify factory buildings, because of its predominant position in the national economy, so it is necessary to pay attention to do much deeper research about the modification of factory buildings.Based on the rebuilding project of the Jinchuan Nonferrous Metals Company’s converter workshop, this paper studies deeply on the propping beams and extracting column method(PBECM) of single story industrial building, puts forward PBECM in which case modification doesn’t destroy the roof through detail study on the original blueprint and field investigation. Firstly, this paper build spatial finite element model of pre modification and post modification plant by SAP2000 and then verify the reliability of the model through vibration analysis and analyze the whole structure of pre modification and post modification statically and dynamically to get the stress state and the horizontal displacement of pre modification and post modification, and supply evidences for proper selection of strengthening members and measures to ensure the overall stiffness. This paper complements comparative analysis about no additional plate of the bracket and unreinforced column, discusses its impact on plant stiffness, and evaluates the rationality of modification project. Secondly, modal analysis of the finite element model calculates the first three vibration mode of pre modification and post modification, analyzes comparatively the impact of plant modification on the overall stiffness of the structure. Finally, this paper applies spectrum response analysis and time-history analysis under longitudinal horizontal earthquake to get the conclusion that: plant modification to some extent reduces the vertical seismic performance of the plant, it has changed the internal force, resulting in the inequality of the stress of the column bracing and the stress of the column bracing located in the removing column increases remarkably. By elastic-plastic analysis, plant modification makes components to advance into the plastic, but doesn’t change the plant yield mechanism of the structure, the column bracing firstly appears the hinge, and then column base next the column bracing, and finally the other column foot, and all none of the column foot destroy, the plant of post modification has enough safety reliability.Practices indicate that, with respect to the project of destroying the roof, PBECM have remarkable economic and social benefits, this paper would provide other similar projects with practical experience and theoretical reference.