Study On Lateral Pressure Of Bulk-Storage Buildings Caused By Granular Materials Under Gravity And Horizontal Earthquake

Silos and airformed RC domes are widely applied to the field of industrial storage.During the process of structural designing,the lateral pressure caused by granular material is the key load to the structure.Airformed RC domes are very different from silos both geometrically and mechanically.However,there is no existing standard aiming at the design of airformed RC domes and there is also some argument over the constitutive model of granular material.Therefore,a finite element model with contact algorithm is built in this paper to calculate the lateral pressure caused by granular material in the gravity field and horizontal earthquake.The model is first applied to silo and later to airformed RC domes.Parametric study on three constitutive models of granular material has been done and the results can offer reference to the future structual design.The detailed research contents and results include:(1)A research on how material parameter affects the lateral pressure has been made respectively by elastic model,Mohr-Coulomb elasto-plastic model and von Wolffersdorff hypoplastic model.Two curves have obtained including the relationship between Young’s modulus and internal friction angle and the one between critical friction angle and internal friction angle;(2)The upper lateral pressure curve of the RC airformed dome is a positive parabolic line and it’s less than the value obtained by Chinese standard.A certain reduction of the upper lateral pressure is suggested.The maximum value of lateral pressure is between the values obtained by Chinese standard and Eurocode.It’s suggested that the upper bound is the Eurocode value.(3)Time-history analysis is committed on the silo FE model under horizontal earthquake.Compared with the test result,base moment of the silo is studied parametrically.The first natural frequency is obtained by FFT method and the FE model is verified.It’s pointed out that the value obtained by modal analysis is bigger than the test value.(4)The simulation is done on an airformed RC dome by above-mentioned model.The concentrated-mass model recommended by standard is also analyzed as a comparison object.It’s found that base moment exceeds the comparison model under certain circumstances,which means the effective mass factor of granular material may exceed 0.8.The distribution of addition lateral pressure is also different from standard and the maximum value may occur on the bottom of the dome.