Author: Mezie Ethelbert

Reading Time: 3 minutes One of the most important aspect of soil investigation processing is sampling i.e. making test holes at desired intervals for observation and to obtain soils for laboratory analysis. The depth of these test boreholes is often vague but these should be predetermined before starting the investigation activities, though, they may change depending on the subsoil encountered in the process. To determine the approximate minimum depth of boring for foundations, engineers may use the rules established by the American Society of Civil Engineers (1972) as described in the steps below: Borehole Depth Step 1 – Determine the net increase of vertical…

Reading Time: 2 minutes Introduction: Liquefaction or quick sand condition of soils is a common term in earthquake prone soils. it is one of the natural hazards associated with earthquakes. Other hazards may include: ground shaking, surface rupture, landslides, lateral spreading, shear failure of foundations, settlement of structures, failure of retaining walls and Tsunami/Seiches. Liquefaction commonly occurs in saturated cohesionless soils and involves the reduction of the shear strength of the soil to zero due to pore water pressure caused by vibration during the earthquake such the soil starts behaving like a liquid. Effects of liquefaction of soils Bearing capacity failureSinking or tilting of…

Reading Time: 4 minutes Introduction: A Rivet is a permanent mechanical fastener (see Figure 1) with head-on at one end and a cylindrical stem called a tail at the other end that has the appearance of a metal pin. Parts of a rivet includes head, shank/body and tail. Rivets are non-threaded fasteners typically made of mild steel, or brass, copper and aluminum. Types of rivet may include: blind rivet, solid rivet, split rivet, friction-lock rivet, self-piercing rivet, drive rivet, span head or cup head rivet, pan head rivet, countersunk head rivet, hollow head rivet etc. They are used in structures, sheet metal operations, ships…

Reading Time: 3 minutes Background: When a clay is compacted at a lower moisture content, it possesses a flocculent structure. Approximately at the optimum moisture content of compaction, the clay particles have a lower degree of flocculation. A further increase in the moisture content at compaction provides a greater degree of particle orientation; however, the dry unit weight decreases, because the added water dilutes the concentration of soil solids per unit volume. Research showed that; 1. For a given compaction effort, the hydraulic conductivity, k, decreases with the increase in molding moisture content, reaching a minimum value at about the optimum moisture content (that…

Reading Time: < 1 minute The following soil types and range of sizes are commonly found in practice

Reading Time: 4 minutes According to Rogers (2018), the functional effectiveness of a highway is measured in terms of its ability to assist and accommodate the flow of vehicles with both safety and efficiency. In order to measure its level of effectiveness, certain parameters associated with the highway must be measured and analysed. These properties include: The quantity of trafficThe type of vehicles within the traffic streamThe distribution of flow over a period of time (usually 24 hours), qThe average speed of the traffic stream, uThe density of the traffic flow, k Among the list above, the last three parameters are usually function of…

Reading Time: 2 minutes Different earth moving equipment have optimum output and cycle times which can be used as a basis for estimating anticipated productivity taking into account the tasks involved, task efficiency of the machine, operating efficiency and in case of excavators, the type of soil. Data for the factors to be taken into consideration can be obtained from timed observations, feedback information from people who have done similar work or are experienced or published tables contained in Manufacturer literature or reliable text books. For information sake, see Table below for approximate productivity rate per day for some labour-based tasks in road construction…

Reading Time: 2 minutes Earthworks is one of the most important aspect of road construction projects and often among the costliest. Earthworks may begin from stripping of topsoil where these are present. However, this is not usually considered among roadwork excavation. Unlike roadwork excavation that is measured in cubic metres (m3), stripping of top soil is measured in square metres (m2) and payment is made in m2. Roadwork excavation consists of the total quantity of measured fill together with the quantity of unsuitable materials and/or excess cut placed to spoil which are determined from the cross-sections of the road. Earthworks shall be measured by…