Abstract
Reinforced concrete (RC) silos are robust structures that are used in many applications of bulk storage, from the mining to agricultural industry. They provide effective storage solutions to the many different types of particulates that they must retain. Due to the circular shape of silos, they resist forces induced by the stored particulates more effectively, and therefore inherently have unique load carrying characteristics. The magnitude and nature of bulk storage structures make these structures prone to structural problems and failures, which requires careful selection of the materials used for their construction, i.e. steel reinforced concrete. Proper engineering design and materials play a critical role in the structure’s ability to prevent failure and collapse. This interaction between the steel reinforcement and concrete together with the design philosophy is what creates a structure that is robust and has a service life that is safe and economical. Structural problems and failures with RC silos are a recurring phenomenon, commonly resulting from inherent design shortfalls and/or construction defects. This research dissertation aims to provide insight into the analysis of RC silos, by comparing the application of BS 8110 (1997) and EN 1991-1-4 (2006) in determining the lateral horizontal pressures that develop at internal faces of silo walls, due to the stored solid particulates. In the research, a silo design case study is conducted on a typical silo configuration and analysed using a classical analytical method and finite element analysis (numerical method). An example of silo design is presented based on BS 8110 (1997) and analysed using the numerical method. The resultant forces calculated in the design example are compared with results of the silo design case study. Concrete strengths of 20 MPa and 40 MPa are used in the silo case study to evaluate serviceability requirements. Finally, stresses in the concrete silo walls and steel reinforcement are determined, then steel reinforcement quantities and crack widths of the two concrete grades are calculated using EN 1992-1 (2004). It is found that the effect of reduced concrete strength has a significant impact on serviceability of the silo structure, but it does not adversely influence the structural capacity.
M.Eng. (Structural Engineering)