Stress Analysis Of Large Diameter Reinforced Concrete Circular Underground Granary Warehouse Roof Slab Structure

In order to study the new generation of green energy-saving new granary,our universityapplied the national "Twelve Five" technological support project： the research anddemonstration of energy saving and efficiency increasing key technology.In this paper, asone of the studies of the project,the primary research is about the stress condition of granarytop.During years of research, our team has identified a variety of new warehouse-typeunderground granary. The reinforced concrete underground granary which is large diametercircular, has become one of preferred options to new warehouse-type underground granary.This article conduct stress analysis of the underground granary top’s beam-slab by thecombination of test result and finite element analysis. Due to the location of the granary, itsforce situation has very big difference with the granary on ground,meanwhile,consideringthe complexity of the granary top’s structural form and force situation,there is nocorresponding calculation method for the granary underground. In order to design a morereasonable granary top structure, we must make the force situation clear. This paper studiesthe stress of granary top’s beam-slab under6conditions,and then provide guidance for theoptimal design of underground granary top. The six conditions were: condition1(thepressure of silo wall only）、condition2（the pressure of silo wall and the upper load of soiltop）、condition3（the pressure of silo wall and grain）、condition4（the pressure of silo walland grain、the upper load of soil top）、condition5（the load of soil top）and condition6（the load of soil top and the pressure of the grain）.It’s difficult to determine the influence of the underground water and soil pressure fortop of silo’s force situation. Therefore, this paper creates a model of the overall with silowall and top of silo,and calculates by applying the loads to the top of silo and silo wall.Through the comparison between the test data of embedded steel bar in the top of soil of thesimulation experiment warehouse and simulated data,it can be seen that reinforcement is under pressure due to the impact of shrinkage of concrete and other non-load factors. Afterthe non-load factors being stable, reinforcement stress will be about37MPa. According tothe result of the finite element analysis, short positions is the most unfavorable condition tothe silo top of the granary underground, the maximum compressive stress appears at theintersection area of soil wall and beam, the maximum tensile stress area is the lower part ofthe middle beam. For the reinforced concrete underground granary top’s beam-slab which islarge diameter circular, the load of the top of soil is the most important factor whichinfluence the internal force variation of the beam-slab, following is the soil and waterpressure outside the warehouse; meanwhile, the influence of containing grain inside or notis very small and can be ignored while design.