Research On Wind Load And The Interference Effect On The Large Gas Tank Structures

With the development of the gas industry and large-scale steel enterprises inChina, the demand for the large gas tank has been increasing. Large gas cabinet isusually designed to be huge cylindrical structure with thin wall and large size. Thiskind of structure is sensitive to wind load which is the main dominant load for design.Due to the gas tank playing an important role in daily production and life, it isnecessary to investigate the distribution of wind load on the surface, the interferenceeffect between cabinets, and the calculation of the equivalent wind load andwind-induced response, which are helpful to find out the approaches for windresistance.Based on the gas tank of Shanghai Baosteel, this thesis has done a series ofresearches about the gas tank and some great achievements have been made. Firstly, itgives an introduction of the analysis methods of equivalent wind load andwind-induced responses based on the theory of random vibration, as well as theclassic design method for the wind resistance by Davenport–gust load factor method.Secondly, wind tunnel test had been carried out with synchronously measuredpressure on the rigidity model of the gas tank in two cases, with and withoutsurrounding buildings. The pressure distribution features on the surface of the gastank have been obtained through the wind tunnel test. As for the gas tank, the averagewind pressure coefficient in each layer of the variations, and shape coefficient alongthe ring to the cabinet are analyzed in detail, as well as the variations of the averagewind pressure coefficient and shape coefficient along the height of the cabinet. Again,the interference effect between pairs of cabinet is detailed discussed by differentspacing of the two gas tanks.Thirdly, the finite element model of gas tank structure had been established in thefinite element program ANSYS. Besides, this thesis analyzes the natural vibrationcharacteristics of the gas tank and proposes the gust load factor method to calculatethe equivalent wind load and wind-induced response of the gas tank structure. Basedon the results of wind tunnel test, the variations of the gas tank top wind-inducedacceleration response and the gas tank bottom of the base shear and basal bendingwith the approaching wind direction changing are investigated. In addition, thedifferences and the reasons of the calculation results under the disturbance of surrounding buildings and without surrounding buildings are discussed in detail.Finally, rigid model testing of a gas tank, with and without surrounding buildings,were performed respectively based on the force balance. The changes of mean and rmsmoments of the base shear and basal bending in two body axes with the wind directionangle are obtained, which shows that there is interference between pairs of cabinets.The overall coefficient of the gas tank is obtained by calculation and analysis of thegas tank bottom of the base shear and basal bending, and has been compared with theload specification.