Papers by Obinna Ranks Ubani
Lecture Notes in Civil Engineering, 2021
In this paper, four different solid shear wall-frame arrangements of equivalent stiffnesses were ... more In this paper, four different solid shear wall-frame arrangements of equivalent stiffnesses were symmetrically placed and considered on a 15-storey (45m) rigid reinforced concrete framed office building; to withstand a wind induced net surface pressure of 0.25 KN/m 2. The three dimensional modelling and analysis of the different shear wall-frame arrangements were carried out on Staad Pro V8i software, and the deformation of the structure in the x, y, z global coordinates (yupwards) were compared when the wind is coming in the z direction of the structure. All the shear walls were modelled to resist lateral load with respect to the z coordinate axis only. This is peculiar to cases where the shear walls are not applied in the core areas of structures like elevators and stairwells. The results show that the best arrangement in terms of minimal storey displacement was the one where the shear walls were positioned away from the centroidal axis of the frame, parallel to the direction of the wind.
In this paper, a twenty storey multi-storey rigid frame was subjected to a uniformly distributed ... more In this paper, a twenty storey multi-storey rigid frame was subjected to a uniformly distributed wind pressure load of 5.05 KN/m 2. The deflection behaviour of the rigid frame was investigated using manual method, and computer based method (finite element analysis). From the results of the two methods employed, it is observed that the value obtained from manual method gave a lower value for the top deflection of the building. The maximum deflection from finite element was 60.441mm, while the result from manual calculation was 55.524mm. This shows that the result from finite element analysis to manual method was about 8.135% greater than that of the manual method. However, this offers a great insight for the speedy check of computer based processes and results.
The famous Maxwell-Mohr's integral forms the backbone of force method of structural analysis, and... more The famous Maxwell-Mohr's integral forms the backbone of force method of structural analysis, and computing of displacements in analysis of beams and frames. It is more ideal for hand calculation purposes than following the direct stiffness method which may involve large matrices which are not very convenient for manual calculation. The Mohr's integral may be solved by direct multiplication and integration of bending moment equations (one linearly and the other of any arbitrary form), or by using the bending moment diagram multiplication/graphical method which is based on Vereshchagin's rule. In this paper, a lot of formulars are derived for combining different shapes of bending moment diagrams for use in the graphical method than can be found in many structural engineering textbooks.
Teaching Documents by Obinna Ranks Ubani
In this paper, the verification of the ultimate load capacity of piles founded in sand was carrie... more In this paper, the verification of the ultimate load capacity of piles founded in sand was carried out according to Eurocode 7. The soil parameters used were obtained from geotechnical investigation from Lekki Pennisula, Lagos.
In this paper, a simplified method of preparing the structural layout of buildings was presented ... more In this paper, a simplified method of preparing the structural layout of buildings was presented especially when the architectural drawing is presented in AUTOCAD format. The idea shows that while it is a technical issue, it is also an art.
In this paper, a statically indeterminate frame to the 2nd order has one of its supports subjecte... more In this paper, a statically indeterminate frame to the 2nd order has one of its supports subjected to vertical settlement by 25mm. The frame is completely analysed using force method, and stiffness methods.
In this paper, a hall of 12m x 20m dimensions was designed with no interior columns using Eurocod... more In this paper, a hall of 12m x 20m dimensions was designed with no interior columns using Eurocode 2. The floor system of the hall was supported by an interaction of primary and secondary beams. The full steps for load analysis, load transfer from secondary beam to primary beam, structural analysis, and full design of the structure was carried out manually. After the analysis and design, a section of 900mm x 400mm, and reinforcement ratio of 1.786% was found to satisfy both ultimate and serviceability limit state requirements of the primary beams. 1.0 Introduction In some construction cases, it is desirable to have large uninterrupted floor areas, and in such cases, the presence of columns has to be minimal. This feature is desirable in buildings such as conference halls, stadiums, churches, dance halls, and all buildings where there is need for performing stage, and spectators. The structural implication of such features is usually the presence of long spans elements, and a lot of solutions already exist for such constructions. It is already a well known fact that the use of beams becomes more uneconomical as the construction span increases. This is primarily because the predominant internal forces in beams are bending moment and shearing forces, which are all functions of the length of the beam. To accommodate these internal forces during design calls for increase in the member sections to satisfy ultimate and serviceability limit state requirements. This further adds to the total dead load of the structure, which is conventionally undesirable for economical reasons. A better solution for handling the problem of long span construction is the use of trusses. Trusses are arrangements of straight members connected at their ends. The members are arranged to form a triangulated system so as to make them geometrically unchangeable, and hence will not form a mechanism. They resist loads by developing primarily axial forces in their members especially if the ends of the members are pinned together. In typical trusses, loads are applied only at the joints. Trusses provide practical and economical solutions to engineering problems. Trusses can efficiently span greater lengths than beams, and hence can be found in roof of buildings, bridges etc. Figure 1.0: Different truss configuration systems, and their possible loading conditions
Uploads
Papers by Obinna Ranks Ubani
Teaching Documents by Obinna Ranks Ubani