Research On Cracking Mechanism And Control Technology Of The Large-diameter Concrete Cement Raw Meal Silos

In modern production practice of many fields, reinforced concrete silos have been widely used due to its predominance such as warehouse capacity, the small size of land occupied and high economical efficiency in use. With the increasing project demand and the gradual improvement and refinement of engineer and construction technology, diameter and height of concrete silo, that markedly increased nowadays, are more than those in the past. The silo wall cracking phenomenon has continued to arise when cement production enterprises used large diameter concrete silos and it is relatively lack of the study of the causes and controlling technologies. So researching the causes and controlling technologies of the cracks in the large diameter concrete silo structures has important theoretical and practical significance.Based on a actual project of large diameter concrete cement raw meal silo in this paper, the author principally carry out a research and achieve some results as follows, by means of theoretical and simulated methods:(1)By the computation comparison among2types of general design methods, it can be concluded that the theory with moment has high accuracy and can reflect the real force of the silo wall.(2)According to the actual project, a model is established by the finite element software MIDAS FEA, and a parameter study has been conducted to investigate pressure effect. The parameters include internal diameter, height to diameter ratio, wall thickness and the bottom rotational restraint stiffness.(3)Some prestress distribution models are analyzed to select the appropriate one and the layout scheme of prestressing tendons are also determined. Then a prestressed silo model is established by MIDAS FEA to study the influence of the prestressing tendons on the internal force distribution of silos and crack control. Finally the optimal allocation of prestressed tendons is also discussed.