Dynamic Analysis Of Thermal Power Plant Steel Main Building Articulated Braced Frame System

With large thermal power plant project requirements increase, the structural design requirements also a corresponding increases. The steel structure itself has the advantages of light weight, high strength and production of convenient installation, so it has become the main form of main building in a large thermal power plant. Compared braced frame structure system with frame support structure system, frame structure system has a lot of advantage, such as manufacturing simple, speeding up the construction progress and saving material. Traditional thermal power plant includes turbine house and deaerator bay and coal bunker, bunker has larger rigidity, can provide larger lateral resistant ability, guarantee the stability of the plant. The braced frame structure system of the main plant which composed of turbine house room and deaerator bay needs seismic analysis to verify that it can meet the seismic design requirements.Anglicizing the seismic performance of steel main building can provide the reference for the application of this kind of project.The Laos hongsa 3 × 600 MW coal-fired power plant project as the engineering background,the thermal power plant of steel structure of main building consists of two parts, turbine house and deaerator bay. It is braced frame structure system. According to the main structure layout uses finite element software Midas/Gen to establish three-dimensional model for modal analysis,adjusts the layout of the support by the modal analysis results. It uses the vibration spectrum method for seismic design of structure decomposition reaction. According to the elastic and elastic-plastic time history analysis of the main building research the seismic performance of the main plant. The elastic stage consists of unidirectional and bidirectional seismic wave input conditions. And the elastic time history analysis results and modal decomposition response spectrum calculation results are compared.The results show that: when the main building longitudinal axis layout two main brace, two main modes of vibration frequency close to the main shaft. the dynamic characteristics of two directions are similar, which can improve the torsion effect. The difference between the results of elastic time history analysis and the response spectrum method meet the specifications. As for the main plant of this kind of irregular structure elastic time history analysis should consider the effect of bidirectional earthquake wave input; Deaerator bay higher part has obvious torsion effect. Under the action of rare earthquake, the maximum storey drift angle is 1/59, although it can meet the requirements of seismic code 1/50, but the margin is less; The seismic response of the bottom of the staggered, column section change parts and the top of deaerator bay is a larger,so these parts become weak part. It should be paid attention to these parts when designing thiskind of structure.