Seismic Research Of Combined Main Building-multiply Supported Equipment System Of Coal Preparation Plant

Multiply supported equipment are often used in industrial buildings, that have large longitudinal length, and across multiple floors, belong to multi-exciter of the building. Pressure filter blow down device in coal preparation plant is typically a kind of multiply supported equipment. Main building-multiply supported equipments in coal preparation plant consists of multiply supported equipment and main building. Dynamic interaction exists in composite system: the property of dynamic and seismic response are changed by multiply supported equipment. At the same time, seismic wave is filtered by main building, the seismic response of the device is affected through multiple point connection. Therefore, it is very meaningful for the seismic design of such industrial structure to study the seismic response of main buildingmultiply supported equipments in coal preparation plant.At first, the mechanical model and dynamic equation of multiply supported system are built, direct method, displacement-input method, relative motion method and large-mass method are adopted to deduce the seismic response of multiply supported equipment. Secondly, regard story shear model of main building-multiply supported equipments as research object, frequency-domain analysis method is adopted to analyze the effect of frequency ratio and site-type to dynamic response of complex system.In order to reduce the dynamic response of main building, the frequency ratio of multiply supported equipment and main building is optimized. Based on SAP2000, three-dimensional model of main building-multiply supported equipments in coal preparation plant is built. The effect of frequency ratio and mass ratio of multiply supported equipment and main building to natural vibration period of complex system are analyzed, and compared with the traditional design method. Under bi-directional earthquake action, elastic time-history analysis of main buildingmultiply supported equipments is completed. The internal force and deformation of important component of main building are studied and compared with the results of traditional design method.The results show that seismic response of main structure is the minimum when the frequency ratio of multiply supported equipment and main building is about 0.9, and the optimal frequency ratio is related to the location of connection point. It is greater influence on dynamic characteristics of main structure when the effect of multiply supported equipment has been considered instead of single supported equipment. The vibration period of first three orders of multiply system have changed significantly when the rigidity connecting main structure floor and supported equipments become greater in amount. Main vibration mode of multiply system has changed when quantity of rigidity connecting main structure floor and supported equipments is less.With the increasing of characteristic site period value, seismic response of the main building become significantly. Compared with single supported equipment, the dynamic interaction of multiply supported equipments and main building is more obvious. The dynamic amplification factor of adjacent to under layer of multiply equipments supporting floors is more obvious, and this tendency is more significant in elastic-plastic stage.