Author: Mezie Ethelbert

Reading Time: 7 minutes Trusses resist axial forces (member forces) only. These forces are usually tension and compression forces. A typical example of a truss member is the roof truss with members such as kingpost, rafters (in roof truss) or boom in other usage, tie members (and not tie beams), etc. The first step in the analysis of a statically determinate structure is to determine the support reactions. This can be done either by using the equations of static equilibrium or by the funicular polygon. Afterward, the determination of the member forces can be accomplished by either of the following methods: Method of Joints…

Reading Time: 2 minutes The following table provides guide on the values of minimum superimposed floor loads to be used for the structural design of buildings and other simple structures according to the Nigerian Code of Practice (NCP 1: 1973). Class Type of Floor/Building Load (kN/m2) 1 Private dwelling not exceeding two (2)storeys in height 1.43 2 Private dwelling exceeding two (2) storeys in height; floors other than those in private dwellings, used for residential purposes; hospital wards and rooms. 1.96 3 Rooms used as offices – floors above entrance floor only. 2.46 4 Classrooms in schools and colleges. 2.94 5 Rooms used as…

Reading Time: 6 minutes Accurate loading of buildings is necessary if accurate analysis and design would be carried out for the building. In the loading of structures, two types of load are encountered, dead load (BS 8110) or permanent action (EC 2) and live load (BS 8110) or temporary action/imposed loads (EC 2). For all types of structures, these two loads are encountered. Permanent actions chiefly consist of the self-weight of the structures or construction works. Self-weight is usually represented as single characteristic value or estimated as the product of the nominal dimensions as shown on the drawings of the structural elements, non-structural elements,…

Reading Time: 4 minutes California Bearing Ratio (CBR) is a very important test used to access the strength of soil prior to construction. Though many new pavement structural design methods such as: empirical-mechanistic and mechanistic methods that are based on stresses are being developed, CBR is still being identified as the best indicator of soil strength despite some challenges in its measurement especially with mixed fine and coarse graded materials. Factors that Contribute to Failure of Subgrades Although subgrade CBR value and design traffic are solely employed in most empirical design formulas to determine the thickness of the pavement layers, it is also necessary…

Reading Time: 2 minutes Fire incidences in buildings are phenomenon that can be avoided but which nevertheless occurs. Reasons for its occurrence include but not limited to: 1. Acts of arson 2. Faulty electrical equipment 3. Human error 4. Poor maintenance of heating equipment 5. Natural events such as lightening To avoid fire incidences, buildings should be designed to minimize the probability of a fire and to protect life and limit property damage if a fire should occur. The steps to achieve this include: 1. Limit potential fire loads, with respect to both combustibility and ability to generate smoke and toxic gases. 2. Provide…

Reading Time: 2 minutes Flood plains are areas that can be overwhelmed by flood. Though not a regular occurrence, when flooding occurs, which chiefly involves rising of a river above its elevation (flood stage), it causes a lot of damage beyond its banks. Generally, it is advisable should not be constructed around flood plains. However, if risk to life of such areas and social and economic considerations justify the construction of buildings at around flood plains, the following points are worthy of note: 1. If there are high areas around the flood plains, preferably cluster the buildings around the high areas. 2. If high…