Research Of Strength And Stability Of Flat-bottom Squat Steel Silos Strengthened With Steel Sheet Strips

Flat-bottom squat steel silo is a vertical storage container which contained granules, powder and other loose material, widely used in cement, metallurgy, coal, electricity, food and many other areas. Compared with reinforced concrete silo, it has a lot of advantages such as simple convenient construction, simplified structure and so on.Silo wall is susceptible to buckle under vertical friction force. Silo is sensitive to small disturbances, easily buckle. For example, it can lead the silo to destruction when the storage declines along the wall down, because of the asymmetric distribution and local stress concentration which the storage material produced on the wall tension and circumferential pressure. The data indicate that, the stress can easily mutate in the location of the changed thickness of the steel strips, and the high stress is nearly close to the critical stress. The steel strips buckle because of the stress level exceeding its capacity.In our country, steel silo made of rolling or assembling steel sheets is thin-walled structure with large radius-thickness ratio and poor stability, and it is easily collapses. In order to ensure safety and extend the service life, it is necessary to firm the silos with security risk. The tradition method is using ring stiffener in the surface of the silos. In this paper, sticking steel strips to the key positions to improve the strength and stability of the silo. Steel-bonded Reinforcement has been broadly used in strengthening structures. It is bonded to surface of structures by adhesive mechanical performance of structures. Bonding steel strips to silo-wall has many advantage compared with welding ring stiffener, such as no stress concentration, no residual stress, easy to construct and low maintenance. Also, the physical and mechanical property of steel is isotropic and good mechanical properties.Numerical analyses including linear stress analyses, linear eigenvalue buckling analyses, geometric-material nonlinear buckling analysis are carried out to investigate the stability behavior and strength of the non-strengthened silo and the strengthened silo with steel stripes. The results show that jacketing steel strips can effectively improve the strength and the stability of the silo.This paper analyzed the effect of thickness, height and location of the steel strips. The strength and the stability of the silo will continuously raise with the increase of the thickness and the height of the steel strips. Increasing the thickness is more effective than others. Sticking vertically is more effective than sticking circumferentially. Limited by the width of the vertical shell strips, there is a certain degree of difficulty. And Sticking vertically is not effective than sticking circumferentially to enhance the strength of the silo.