Prestressed Concrete Silos Stress Test And Finite Element Analysis

As the storage of bulk containers with the large volume,small land area,simple operation,environmental protection,low consumption and other advantages,has been sought after by the production practice industry.China's coal silo continues to develop in the direction of large capacity in recent years.However,the research of the lateral pressure of the silo wall caused by the storage load is much more than the study of the effect of the prestressed tension on the hoop stress of the silo.Under the influence of factors such as actual construction,environmental change,material aging,structural damage and so on,the prestressed steel strand(steel beam)will result in the loss of initial stress.The degree of stress loss is increasing under the interference of many factors,the effective prestress is reduced,and the safety factor is smaller.Therefore,in this paper the main work and achievements of the unbonded prestressed concrete silo in Inner Mongolia are as follows1?Through the finite element software ANSYS to the ordinary concrete silo and silo static performance analysis and prestressed tendon layout on silo wall stress analysis of influence discoveried: Prestressed silo can better control the development of silo cracks and if there is no tensile stress after the prestressing force is arranged in the larger part of the reinforcement,the tensile stress will not exist in the silo wall.This is not only can improve the working performance of the silo structure,but also can save the economic cost.2?Through the long-term monitoring of the data processing silo each circu mferential stress with time variation and ordinary steel bar stress and concrete stress sustained growth to peak(240d/112d)after a slow decrease trend;The v ariation of the height of the wall along the silo is basically a trend of decreasi ng with the increase of the height of the silo.3?The stress of prestressed tendon decreases with time,but there is no regularity along the height;The total stress loss increases to a stable parabola: 0 ~ 75 d loss rate is very fast and 75 d ~ 330 d stress loss began to rise slowly.4 ? The total prestress loss averaged 24.89% which the instantaneous loss of19.37% accounted for 77.82% of the total losses Because of the short monitoring time so the proportion of long-term loss is small but it will also increase the prestress losswhich can not be ignored;The total loss is larger than the recommended value of the bridge engineering loss 20%which is big about 4.89%.It is found that the temperature stress has a great influence on the stress change.In order to make the effective stress reach the expected effect,it is suggested to increase the tension control stress.5?A simple error analysis is made for the long-term monitoring data.