Experimental Study On Pressure Of Large - Diameter Concrete Shaped Cylinder Under Eccentric Discharge

The internal force of squat silo structure is asymmetry under the effect of eccentric discharge. It increases the complexity of structural stress and the difficulty of structural design. This paper was supported by the National Natural Science Foundation "Research on Dynamic Action Mechanism and Design Method of the Wall in Large-diameter Concrete Squat Silos under Eccentric Discharge". The experiments of eccentric discharge of scale silo model were carried out. The lateral pressure distribution model of squat silo under eccentric discharge was obtained. The major work and achievement are described as follows:In order to study the lateral pressure distribution of silo wall under eccentric discharge, experiments of squat silo model were carried out under eccentric discharge in this paper. The results showed that the intense fluctuate and overpressure phenomenon of lateral pressure occurred more easily near the silo outlet in single hole discharge. The overpressure measuring point located 1/3 to 2/3 height away from bottom.While the dynamic action was not obvious away from the silo outlet. When the squat silo was strip discharged, the overpressure phenomenon was more obvious, and overpressure measuring point located 1/6 to 2/3 height away from bottom.A series of experiments were carried out with different eccentricity ratio, ratio of height to diameter and flow velocity. The results showed that overpressure coefficient presented the trend of becoming larger with the increase of eccentricity ratio. The overpressure phenomenon appeared more easily at the top of silo with the increase of ratio of height to diameter. The measuring points that overpressure coefficient was greater than one were increasing gradually. The overpressure phenomenon appeared more easily at the top of silo with the decrease of flow velocity, and the overpressure position of silo was affected by the direction of storage flow.The eccentric discharge process of squat silo was based on the discrete element method (DEM) software. The lateral pressure of the silo wall obtained from DEM agreed with the measured values of the tests, as well as the specification. The stored material under eccentric discharge showed the funnel shaped pattern by analyzing particle velocity fields and force fields. The maximum of dynamic lateral pressure of the silo wall occurred in the initial stage of discharge process and the overpressure of the upper wall was more serious than the lower wall.The lateral pressure distribution models of silo wall under eccentric discharge in the specifications of China, Europe and Australia were compared. Then the application scope, the advantages and disadvantages were discussed. According to experimental results and numerical simulation results, the distribution model of lateral pressure of squat silo under eccentric discharge was proposed.