This research is focused on the constant pavement failure in parts of the Enugu-Onitsha expressway. The failed portions are constructed on the natural subgrade known to be the Shale of Enugu and Mamu Formations. Five (5) samples each were obtained from the Formations and were subjected to geotechnical test, mineralogical analysis, scanning electron microscopy (SEM) and, statistical analysis. The outcome of the geotechnical test revealed that the liquid limits (LL) are of high plasticity with values ranging from 57.69–62.61% and 53.57–56.24%, plasticity index (PI) values ranging from 20.32–24.37% and 13.37–15.32%, Slake durability index (SDI) values ranging from 0.55–31.8% and 63.4–71.6%, for Enugu and Mamu Shales respectively. From the Unconfined compressive strength (UCS) test, the cohesion (C) values ranged from 37.36–43.89KPa and 24.22- 27.07KPa, soaked California bearing ratio (CBR) values ranged from 1.03–1.22% and 0.90–1.60% for Enugu and Mamu Shales respectively. The test results are below the requirements laid down by the Federal Ministry of Works and Housing (FMWH) for pavement construction. X-Ray Diffraction (XRD) analysis revealed major minerals to be quartz and kaolinite. Moreover, kaolinite disperses and migrates when moist hence geotechnical failure. Images from SEM revealed the presence of micropores and fractures which can be used as a reference to the geotechnical test results. Statistical analysis of key geotechnical parameters such as SDI, PI, C, and CBR revealed a strong correlation. The evaluated results pointed out that the underlined natural subgrade is poor for pavement construction, and thus requires stabilization.

In Warri, Delta State, Nigeria, 17 groundwater samples were collected and examined using the American Public Health Association (APHA) method. to evaluate the hydrochemical characteristics and health risks connected with using them as drinking water. For the assessment of the impact of heavy metal contamination in groundwater resources within the region, statistical index analysis using Principal Component Analysis (PCA) and Pearson correlation, heavy metal index such as Contamination Index (CI), Contamination Factor (Cf), Pollution Load Index (PLI), Metal Pollution Index (MPI), Quantification of Contamination (QoC), Potential Ecological Risk Index (ERI), and Pollution Index of Groundwater (PIG) were successfully applied. Additional findings from Pearson correlation and Principal Component Analysis (PCA) suggested that there is an interaction within the groundwater aquifer system and that there are weak to moderate relationships between parameters. PCA also suggests that loadings within the groundwater system may have resulted from anthropogenic activities in the area that are affecting the water chemistry. Results from hydrogeochemical facies showed that in the cation area, Na+K > Mg > Ca > Cl > SO4 > HCO3 with a tendency of 35.3 percent SO4 > 5.9 percent HCO3 > 41.2 percent Cl > 17.6 percent no dominant ionic specie. Findings from heavy metals indexes like Cf and PLI suggested that there is no connection between them and the groundwater that is readily available. Additional MPI results showed that the research area's groundwater is regarded as clean, whereas QoC and ERI findings showed that geological processes promote the transport of heavy metals, the possible ecological danger associated with groundwater. The HI for all indicators was higher in children than in adults, according to health risk data. This increasing HI in the studied area may be primarily due to anthropogenic sources. According to the findings, ongoing groundwater assessment is necessary to warn against a decline in groundwater quality in the research region.

The study involved an integration of field observations, geotechnical analysis, slope stability analysis, gully expansion rate analysis and determination of the soil erodibility factor (K). Fifteen representative gullies were studied extensively. The Grain size distribution analysis revealed that the soils are composed of gravel (5.77–17.67% and 7.01–13.65%), sand (79.90-91.01% and 82.47–88.67%), and fines (2.36–4.05% and 3.78–5.02%) for Nnewi and Nnobi respectively. The cohesion and internal friction angle values range from 1–5kPa and 2-5kPa and from 29–38° and 30–34° for Nnewi and Nnobi respectively, which suggests that the soils have low shear strength and are susceptible to shear failure. The plasticity index (PI) of the fines showed that they are nonplastic to low plastic soils and highly liquefiable with values ranging from 0–10% and 0–9% for Nnewi and Nnobi respectively. Slope stability analysis gave factor of safety (FoS) values in the range of 0.50–0.76 and 0.82–0.95 for saturated condition and 0.73–0.98 and 0.87–1.04 for unsaturated condition for both Nnewi and Nnobi respectively indicating that the slopes are generally unstable to critically stable. The erosion expansion rate analysis for a fifteen-year period (2005–2020) revealed an average longitudinal expansion rate of 36.05m/yr and 10.76m/yr for Nnewi and Nnobi gullies respectively. The soil erodibility factor (K) are 8.57x10− 2 and 1.62x10− 4 for Nnewi and Nnobi respectively indicating that the soils in Nnewi have higher erodibility potentials than those of Nnobi. Conclusively, both the Nnewi and Nnobi areas are highly prone to erosion.

The failure of civil engineering structures especially buildings by severe cracks, partial, or complete collapse have kept the natives of communities in Aguamede and Ehamufu (Southeastern Nigeria) communities in a bothered state. Detailed geotechnical techniques and X-ray diffraction analysis were applied to investigate the soil samples from the study area. Geotechnical results revealed that the soil of the area have high clay content (62.78–82.37%), high liquid limit (48–54%) with a plasticity index of 20–28%, high moisture content (25.06–27.28%) and low permeability of 2.21 × 10–8–1.74 × 10–6 (m/sec) which hinders drainage. Maximum dry density values were in the range of 1.73–1.98(g/cm3) with an optimum moisture content of 17.5–19.8% and average specific gravity of 2.5 (mg/m3). Shear strength test revealed high cohesion (32–36.4 KN/m2) to low angle of intergranular friction (10–12°). Coefficient of consolidation ranges from 0.04 to 0.94 m2/year were observed. Coefficient of volume compressibility values were in the range of 0.00012–0.00028 m2/kN and showed that the soils are highly susceptible to compression as the foundations are underlain by an inadequate soil layer that is vulnerable to settlement in amount ranging from 0.553–0.654 mm/year at load pressure of 400 kN/m2. X-ray diffraction analysis revealed that the mineralogy of soil in the study area consist of quartz (89–89.7%) and kaolinite (10.3–11%). Statistical analyses showed that specific gravity, cohesion, clay, silt, NMC, PI, sand, LL and phi have strong interrelation in the correlation table. Comparing the geotechnical parameters from the study area with the Nigerian specification for constructions, it is shown that the study area has poor foundation materials.

The drinking water quality of Akure, in the Ondo State area of southwestern Nigeria, was assessed. 21 groundwater samples were collected and tested for physicochemical characteristics such as pH, main ions, and heavy metals from motorized boreholes and hand-dug wells. From the hydrogeochemical modeling, it shows 77.3% of the samples are of the geochemical zone of 4 (strong acids exceed weak acids) while 22.7% of the samples are of the geochemical zone of 3 (weak acids exceed strong acids) with a hydrogeochemical trend of Mg > Na + K > HCO3 > Cl > SO4 > Ca. WQI results revealed that groundwater needs proper treatment before it can be fit for different purposes. Contamination Factor results showed minimal contamination, Metal Pollution Index revealed that 80.6 percent of the samples had values more than 6, suggesting that they were severely contaminated. Pollution Load Index values in the area were less than 1 showing there isn't any pollution. Geoaccumulation Index results showed that 47.6% of the samples are respectable contamination while 47.6% of the samples are modestly dirty. Principal Component Analysis results indicated loadings of variables within the PCI, PC2, and PC3 while the Correlation Matrix results indicated that there exists weak correlation amongst elements and the majority of the elements. From statistical approach of health risk assessment, it was observed that traceable absorption of poisonous heavy metals have resulted to diarrhea, typhoid fever, cholera, hepatits A and dysentery commonly found in children and youths in the study area. The results of the Hazard index showed that children were more prone to heavy metal hazards. Regular monitoring of the groundwater sources is highly recommended.