DEPARTMENT OF CIVIL ENGINEERING

This project examines road traffic accident problems in Benin City, Nigeria in an epidemiological approach. The project entails the source of data compiled in a questionnaire, hospital records, FRSC reports and press media data on accident reports. The identification of risk factors, data interpretation of accidents and their general preventive measures are discussed. Accident prediction models are used to predict future occurrences. The Haddon Matrix Analysis was used to model the Pre-crash, Crash and Post-crash phases of accidents. This is done to determine to what extent accident and casualty involvement are related, and so assist policy makers and relevant authorities to explore counter-measures in the allocation of scarce resources in reducing road traffic accidents. The generalized linear regression method (GzLM) was modelled using number of accident outcomes as the dependent variables while the time of the day (T), host (H) and speed (Sp) of the accidents were selected as the independent variables so as to obtain a model equation.

The soil water characteristic curve (SWCC) is a graphical relationship between the matric suction (pore water suction)  and the water content (gravimeter  or volumetric  or degree saturation s). It is one of the basic characteristics of unsaturated soils and as such, it is useful for estimating the other properties of soil when solving engineering problems in areas like fluid flow, irrigation scheduling, compressibility and shear strength. SWCC also provide input to the design of a compacted clay cover liner and earth Dam due to its potential impact of flow rate and the dessication processes. Since the experimental procedures, in which a filter paper or pressure plate test adopted for determining the matric suction-water content relationship is time consuming and cost-intensive, hence the need to produce the SWCC using some mathematical functions (models). The fundamental aim of this research is to determine the mechanical behaviour of lateritic soil using SWCC. The soil samples that were used in this research work are residual reddish brown lateritic soil that was obtained from University of Benin Campus. The method of disturbed sampling was employed in obtaining soil samples for laboratory testing. Full laboratory investigation were carried out on the soil samples, these include; liquid limits, plastic limit, plasticity index, liquidity index, specific gravity, particle size analysis and specific gravities. Soil water characteristics curve (SWCC) specimens were prepared with one compactive effort (BSL) to relative OMC. 2.5kg of each specimen was moistened with tap water, mixed thoroughly and compacted in BS moulds and later cored into stainless steel rings with inside diameters of 50mm and heights of 50mm with the aid of a mallet. Each of the 15 specimens was covered with caps at both ends before saturation. The samples were subjected to full saturation by capillary action for a period of 3 weeks. The pressure plate drying test used in this study was conducted to determine the relationships between volumetric water content and matric suction potentials in a soil subjected to pressures ranging between 0 - 1500kPa. Pressure was applied to a predetermined value to induce matric suction. Testing was terminated when the outflow stopped indicating that specimens had equilibrated with the applied matric suction. The specimens were removed and their volumetric water content was determined. The procedure was repeated to develop an entire SWCC by subjecting the soil specimens to different pressures (0 – 1500kPa). In this study, the author used 3 models and they are Van Genuchten equation, Fredlund and Xing equation and Brooks – Corey equation. With the data from the pressure plate extractor to predict hydraulic productivity and volumetric water content of the soil samples. The results of index properties shows that the natural moisture content of the soil is between 36%- 46%, plasticity index is between 17,92% to 28.03%. The specific gravity is between 2.31%-2.57% and the soil is classified as lateritic soil of low plasticity. The SWCC data from pressure plate extractor have been fitted with Van Genuchten (1980); Brooks-Corey (1964); Fredlund and Xing (1994) equation. The result show that the air entry value and residual matric suction for residual soils are in the range of 18kpa to 30kpa and 43kpa to 670kpa respectively.The result shows that: Generally, Van Genuchten and Brooks-Corey models over predicted volumetric water content (θ) at low suctions, while Fredlund-Xing model under predicted it but the values are close to laboratory measured values

In this study, the levels of tin (Sn), antimony (Sb), iron (Fe), cadmium (Cd), lead (Pb), and zinc (Zn) in soil and vegetables were examined, as well as the potential health risks of eating vegetables obtained from areas around second cemetery, Iyakpen, Benin City, Edo state, Nigeria. Soil samples were collected with hand auger from 0 – 20cm depth, air-dried, powdered, and sieved. Four different vegetables (mango, orange, potato and bitter-leaf) were also were randomly collected from around the cemetery and transported to University of Benin Civil engineering laboratory, Benin City, Nigeria, for sample preparation. The vegetables were washed with distilled water to remove any traces of dirt, separated, air-dried and further dried in oven for 72 h at 65 °C to attain constant weight. The dried leaves were then pounded with a mortar and pestle and converted to powder and stored each in a plastic bag for analysis. The soil and vegetable samples were analyzed with a wavelength dispersive X-ray fluorescence spectrometer (SKYRAY INSTRUMENT EDX3600B). Health risk indication parameters (health risk index, daily intake of heavy metals and target health quotient) were evaluated.

In rural areas, water contamination remains a major public health concern, exposingresidents to chemical and microbiological pollutants that can cause severe illnesses. Many households rely on untreated water sources such as wells, boreholes, and rivers, which often contain pathogenic microorganisms and elevated levels of heavy metals exceeding recommended safety limits. This study evaluates boiling as a low-cost, effective domestic water purification method, alongside other household treatment options such as filtration, coagulation, chemical disinfection, and distillation. Water samples were collected from the Obazagbon Community and analyzed in the laboratory to assess physico-chemical and microbiological parameters both before and after treatment. A multi-criteria decision analysis (MCDA) framework was applied to rate each purification method based on cost, effectiveness, feasibility, simplicity, sustainability, and accessibility. The results demonstrated that boiling significantly reduced microbial contamination, including total coliforms and E. coli, bringing bacterial counts well within the acceptable limits set by WHO and NSDWQ. Specifically, total coliform counts decreased from 149 CFU/ml (Sample A) and 153 CFU/ml (Sample B) to non-detectable levels, and E. coli was completely eliminated from the treated samples. In terms of chemical pollutants, boiling had limited impact. Levels of dissolved metals such as zinc (1.738 mg/L initially reduced to 1.520 mg/L), iron (0.798–0.801 mg/L), cadmium (0.015–0.018 mg/L), and lead (0.063–0.065 mg/L) remained largely unchanged after boiling, highlighting that thermal treatment primarily targets microbial contaminants and cannot remove dissolved chemical pollutants. Physicochemical parameters such as pH remained within safe limits (6.20–6.23 post-treatment). The persistence of metals is attributable to the geological composition of water sources and potential contamination from human activities, including agricultural runoff, poor waste management, and corroded plumbing systems. Overall, the study confirms that boiling is a highly effective method for microbial disinfection

This study evaluates lightweight concrete produced by partially replacing conventional coarse aggregate with crushed coconut shells, aiming to develop an eco-friendly and cost-effective solution for rigid pavement construction. The research investigates the feasibility of using coconut shells (a readily available agricultural waste) as a substitute to reduce concrete's overall weight while maintaining adequate structural performance. A comprehensive experimental test was carried out in which concrete mixes were designed with varying levels of crushed coconut shell replacement (e.g., 0%, 10%, 20%, and 30%) for the coarse aggregate replacement. The fresh concrete properties were evaluated using standard slump tests, while the hardened concrete was tested for compressive, flexural, and splitting tensile strengths at 7, 14, and 28 days of curing. The tests were conducted following standard procedures, and the resulting data were tabulated and compared across different replacement percentages. The 7-day compressive strength for the control mix (0% replacement) was 21.09 N/mm², while the 10% replacement mix recorded 20.48 N/mm²; at 28 days, the control mix achieved 30.51 N/mm² compared to 28.27 N/mm² for the 10% replacement. Similarly, flexural strength values at 28 days decreased from 5.75 N/mm² for the control to 5.25 N/mm² at 10% replacement.

This research work, evaluated the speed bumps in the Osasogie Community with the use of geospatial techniques. Speed bumps, are important traffic calming devices seen on our roads, which help to physically reduce traffic speed. The work was done in two phases, which were the field study and the questionnaires. During the field study, the coordinates of each speed bump was taken as well as the geometric properties of each speed bump which were the height, length, width and the clear spacing. A comparison was done on the geometric properties of these speed bumps, using the standard of the ‘Federal Heights Municipal Code of Colorado, USA’. A handheld GPS receiver was used to take the coordinates, while measuring tapes were used to measure the geometric properties. The standard width of speed bump was between 0.6m and 1.2m, the standard height was between 0.07m and 0.1m, while the standard length was between 3.65m and 5m. In total, 22 speed bumps were analyzed from 4 streets, of which only 4 speed bumps met the design criteria, which was 18.18% of the entire speed bumps. Also the clear spacing of the speed bumps in all the locations, did not meet the design criteria, as they were either too close to each other, or too far apart. From the questionnaire survey, it showed a vast variation in the response, based on the point of view of each respondent, however, majority of the respondents, were satisfied with the application of speed bumps, in the study area