Shaking Table Test And Numerical Analysis Of Column Bearing Silos

China is not only a large agricultural country,but also a country with abundant natural resources.It has a large amount of storage in grain,coal,building materials and chemical industry.As one of the storage and transportation structures,the cylindrical silo is simple and clear,and its ventilation and lighting are good.It has been developed rapidly and has been widely used.China is in the Pacific seismic belt and the Eurasian seismic belt,which is one of the most serious earthquake disasters in the world.As an important hub structure in the storage lifeline system,it will bring great property loss to the country and the people once the silo is destroyed.This paper takes the actual project as the research background.The seismic model test of column supported silo is carried out on the simulated vibrating table,and the finite element model of the silo structure prototype is established to be compared with experimental results,in oder to study the damage characteristics,failure modes of column supported silos and the effects of aftershocks on structural cumulative damage.The specific research contents include the following aspects:(1)The dynamic characteristics and dynamic response of the silo are studied through the shaking table test of the column supported silo model.Under the empty storage condition,the silo structure is in the elastic range,and there is no plastic deformation.Under the full storehouse condition,the structure has obvious transverse and oblique cracks on the column top and the column foot with the increase of peak acceleration of the ground motion,and the column top and the bottom of the column are the weak parts of the structure.But the wall of the silo does not produce cracks during the whole test process.The peak acceleration of seismic waves is reduced to simulate aftershocks.After the main shock action,the structure has been damaged,and the structural damage has become larger after aftershocks.(2)The modal analysis of the prototype is carried out.The dynamic characteristics of the structure are verified by comparing with the test results,and the rationality of the established finite element model is verified.The one or two order frequency of the structure is equal and the four or five order frequency is equal.(3)The static analysis of the prototype was carried out,and the static pressure measurement values,theoretical calculation values and model test values of silos are compared and analyzed.The dynamic pressure of silos is larger than that of static ones,and increases with the increase of the peak acceleration of seismic waves.Under seismic action,the pressure at the top of the silo wall is increasing rapidly,and the design of storehouse roof in seismic design needs to be strengthened.(4)The time history analysis of the prototype was carried out.It is further determined that the structure is easy to be damaged at the top of the column and the bottom of the column,and the structural design should be strengthened.(5)Cumulative damage analysis of column supported silos is carried out.Aftershocks make the overall damage of the structure larger.With the increase of aftershock peak acceleration,the overall structural damage increases.The influence of the aftershock on the structural damage can not be ignored.Aftershocks not only increases the structural damage caused by energy dissipation,but also increases the displacement of the structure,resulting in the overall structural damage.