This study investigated the effects of cement and lime on the mechanical properties of subgrade soils, which are challenging to stabilize due to high plasticity and swelling potential. The study found that both cement and lime are effective stabilizing agents that increase the OMC, with cement being more effective in reducing the OMC of black cotton soil. The engineering properties of stabilized Chokocho subgrade soil were also evaluated, and the use of cement and lime as stabilizers was found to be effective in improving soil characteristics for subgrade applications. This was indicated by increased maximum dry density values, reduced plasticity index values, and increased California bearing ratio and unconfined compressive strength values. The chemical composition test demonstrated that calcium plays a significant role in soil stabilization, while aluminum can potentially affect soil stability negatively. Other elements such as magnesium, iron, silicon, zinc, and nickel contribute positively to soil stability. The low amounts of lead, copper, manganese, potassium, sulfur, and titanium present in the soil indicate a minor contribution to soil stabilization, but their impact on soil properties and plant growth cannot be ignored. Overall, the study highlights the importance of considering specific soil types and conditions when undertaking soil stabilization projects. The findings provide valuable information for future research in this field, particularly in investigating the effectiveness of other stabilizers and their interactions with specific soil types. The use of cement and lime in soil stabilization is an effective method for enhancing the strength and durability of weak soils, as shown by the reduction in plastic limit values observed in the stabilized soil samples. The appropriate content of cement and lime to use in soil stabilization could inform standards and codes for soil stabilization.

In Nigeria, it is standard practice to discharge petrochemical compounds on sewage degradation in a septic tank, which has led to consistent sewage dislodgement in the septic tank that serves our household. The study was carried out to determine the effect of some petrochemical products, such as petrol, kerosene, and diesel. Some laboratory tests were conducted, which included biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, conductivity, and total coliform count. Under aerobic conditions, the researchers built four different experimental sewage treatment systems in the lab. We used a scale ratio of 2: 1 for the effluent and petrochemical products in order to get a total mixture of 200ml for both since the reagent bottle, we used for the test has a total measurement of 300ml. With respect to the above ratio, 33 mL of effluent and 67 mL of petrochemical products such as petrol, kerosene, and diesel were poured into each of the three samples (i.e., the 300 mL reagent bottle), and the last sample was used as the control. Samples were collected at a weekly interval for a period of four weeks for the laboratory tests. The findings of the tests revealed that there was a slow rise in the BOD and the COD during the second week, but that this rise eventually slowed down and became smaller over the course of time. Weekly, the pH, conductivity, and total coliform count decrease. The abrupt spike in the second for BOD and COD is due to the presence of additional carbon, hydrogen, and oxygen molecules, which eventually decrease with time. This merely indicates that petrochemical products have the potential to be utilised in the reduction of biological oxygen demand (BOD), chemical oxygen demand (COD), and coliform bacteria found in sewage.

Residual soils are in the category of questionable soils which have been experienced in the arid and semi-arid climatic zones of the world. The conditions in these zones favour the development of most unsafe collapsible soils. At their dry natural state, they possess awesome stiffness and high apparent shear strength, however upon flooding, may demonstrate a remarkable reduction in volume, consequently deteriorate in strength and collapse. In this research, the collapse phenomenon of residual soil collected from three locations in Auchi, Northern Edo, Nigeria has been investigated on undisturbed specimens by utilizing single Oedometer test. The results obtained from Oedometer tests were utilized to form the database to develop the Artificial Neural Network model for the prediction of collapse potential induced by flood. The influences of flood, flooding pressure, void ratio, dry density and porosity on soil collapse have been investigated. Six input parameters (i.e. Flooding Pressure, Initial void ratio, Initial water content, Initial dry density, Liquid limit and Initial porosity) are considered to have the most noteworthy influences on the degree of collapse and have been utilized as the model’s inputs while the model output will be the equivalent collapse potential. The proposed network was developed using Microsoft Visual Studio 2010 and the MS.NET Framework 4.0 and source codes were written in C-Sharp (C#). A supervised learning was utilized to train the Back Propagation feed forward multi-layer ANN algorithm with the momentum coefficient and learning rate as its parameters. The prediction performance of the Artificial Neural Network model was assessed by utilizing the primary statistical criterion proposed by Shahin, et al., [1] such as the coefficient of correlation, R2, and the root mean square error, RMSE. The model outcomes demonstrated that it has the aptitude to predict the collapse potential from single Oedometer test in residual soil samples with a good degree of precision with coefficient of correlation, R2 = 0.856 and root mean square error, RMSE = 166.199.

This research work presents a study of the reliability of ground improvement methods in three states of the Niger Delta Area of Nigeria namely: Rivers, Bayelsa and Akwa –Ibom states. Natural soil which is peaty clay in nature was obtained from different locations in the area of study and improved with different percentages of chemicals, cement, ranging from 2% to 10% and geotextile materials after which reliability analysis was carried out on them for CBR and UCS tests. Results show that geotextile materials are not suitable for improving the peaty clay soils in the locations under study due to poor values of reliability while the reliability values obtained for soil improved with cement increases with increase in percentage addition of cement and curing period. Reliability values for soil improved with chemicals shows some variability but increase as curing period increases at percentage addition of chemicals from 2% to 6% for Calcium Oxide, Calcium Chloride, Calcium Hydroxide and Aluminium Hydroxide before a decrease in value. Sodium silicate reliability peaked at 8% while the optimal value of reliability for cement was realised at 10%.