Foundation Settlement Determination: A Simplified Approach

The heterogeneous nature of the subsurface requires the use of factual information to deal with rather than assumptions or generalized equations. Therefore, there is need to determine the actual rate of settlement possible in the soil before structures are built on it. This information will help in determining the type of foundation design and the kind of reinforcement that will be necessary in constructions. This paper presents a simplified and a faster approach for determining foundation settlement in any type of soil using real field data acquired from seismic refraction techniques and cone penetration tests. This approach was also able to determine the depth of settlement of each strata of soil. The results obtained revealed the different settlement time and depth of settlement possible

Attenuation Variability in Porous Media: Effects on Phase Delay and Quality Factor

Electromagnetic methods of surveying involve the propagation of time varying low frequency electromagnetic fields in and over the earth. This gives rise to a secondary electromagnetic field and a resultant field which is picked up by suitable receiving coil. This research work modelled electromagnetic method of survey using a Cathode Ray Oscilloscope and a signal generator. This work was aimed at relating the effects of phase delay and the quality factor of a propagating signal to some properties of the homogeneous medium, like porosity (compaction), permeability and hydraulic conductivity. River bed sand was used as the sample, it was washed, oven dried, sieved into different grain sizes and the porosity was determined. Each sample was packed in a square box and connected to a signal generator and an oscilloscope. Two sinusoidal waves of the same frequency, but different amplitudes were sent from a signal generator and the measurement was taken at different frequencies. Graphs of frequency were drawn each against phase delay and Q – factor. Graphs of porosity were drawn each against phase delay and Q – factor. In conclusion, we observed that the porosity of a material increased with the decrease in the mixture of its grain size and signals were more attenuated at lower frequencies but as the frequency of the input signal was increased, the material became more permeable to the passage of the input signal. Keywords: porosity, attenuation coefficient, phase delay, quality factor and electromagnetis

RADIOLOGICAL RISKS OF RADIUM-226 ON GROUNDWATER BASED-DRINKING IN KUBWA AND GOSA AREA OF ABUJA , NORTH CENTRAL NIGERIA

The radiological risks associated with radium-226 in groundwater samples were analyzed using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The mean annual effective dose from the natural radionuclide of radium-226 (226R) was estimated to be 2.2 x 10‒5 mSv. In the groundwater samples, Lifetime average daily dose (LADD) ranged from 1 x 10‒3 to 2 x 10‒3 μg kg‒1 day‒1. The LADDs and the highest cancer mortality risk was found at Kubwa borehole with a value of 3.1 × 10‒8 and lower value reported at Gosa borehole with a value of 1.8 x 10‒8 . The highest cancer morbidity of 9.7 x 10‒9 was noted at Kubwa whereas lower value of 5.2 x 10‒9 reported at Gosa borehole. The radiological risks of 226Ra in the water samples were found to be low, typically in magnitude of 10−7. With this low level of radiological implications, it may be the chemical toxicity associated with 226Ra as a heavy metal. The values obtained in the study area may not pose radiological hazards to the residents that rely on groundwater. At the same time, measures of groundwater quality protection and monitoring should be enhanced and new supply source which has lower risk must foun

Geochemical Analysis of Domestic Groundwater Sources in a Suburb of Ota, Southwestern Nigeria

Groundwater as one of the most valuable natural resources supports human health, economic development and ecological diversity. The activities of many constituents related to groundwater such as micro-organisms, gases, inorganic and organic materials can lead to contamination of well water, municipal drinking water sources and the environment. Therefore, geochemical analyses of domestic groundwater sources within Iju, Southwestern Nigeria have been conducted to determine the groundwater properties of water samples from available hand-dug wells and boreholes within the area. Fifteen (15) water samples sourced from wells and boreholes within the study area were analyzed for their major trace elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in the laboratory and physiochemical characteristics such as pH, total dissolved solids and conductivity were calculated to determine the suitability of such water for agricultural and domestic consumption. The bulk analysis on the water samples revealed that majority of the trace elements when compared with the World Health Organization (WHO) drinking water standards and Acme Laboratory Canada Method Detection Limits (MDL) have values that agree with the recommended limit. These findings show that the present status of groundwater in Iju is good for domestic and agricultural purposes. However, the presence of trace elements such as Lead, Bromide, Copper, Potassium, Manganese, Rubidium and Silicon in fairly high quantities in the groundwater samples which may be as a result of treatment in the water or dissolved salts in the groundwater may constitute major health hazards if not quickly checked. In spite of groundwater studies done in Ota, important information on groundwater resources in Iju is still largely unavailable. Thus, groundwater management can be effectively planned based on these results for the stud

Assessing the Life Average Daily Dose (Ladd) due to Heavy Metal Contents in Water Samples from Covenant University, Canaanland, Ota, South West Nigeria

The consumption of water with elevated concentration of lead (Pb) can prevent Hemoglobin Synthesis (Anemia) and results in Kidney diseases. A cross sectional study was conducted in to estimate the risk of exposure to lead via groundwater and bottled water ingestion pathway for the population of Covenant University, Canaanland, Ota, Ogun Sate using Perkin Elmer Optima 8000 ICP-OES. The concentration of Pb, Cr, Cd and As varies from water sample to another with the highest value of .7.07 ¹gL¡1 was noted in borehole water sample (BH1) behind John Hall. Comparing the value with the International recommended level by USEPA and WHO respectively, 7.07gL¡1is less than 15¹gL¡1 and 10 ¹gL¡1. The Life Average Daily Dose (LADD) estimated in this present study reported higher in BH1 for lead (Pb) and could pose health hazard if accumulated for a long time. This work suggest measures to employ quality water treatment plant to reduce the level of heavy metals in the selected water samples and also more research on radioisotopes in the same water sample

Geochemical Analysis of Domestic Groundwater Sources in a Suburb of Ota, Southwestern Nigeria

Groundwater as one of the most valuable natural resources supports human health, economic development and ecological diversity. The activities of many constituents related to groundwater such as micro-organisms, gases, inorganic and organic materials can lead to contamination of well water, municipal drinking water sources and the environment. Therefore, geochemical analyses of domestic groundwater sources within Iju, Southwestern Nigeria have been conducted to determine the groundwater properties of water samples from available hand-dug wells and boreholes within the area. Fifteen (15) water samples sourced from wells and boreholes within the study area were analyzed for their major trace elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in the laboratory and physiochemical characteristics such as pH, total dissolved solids and conductivity were calculated to determine the suitability of such water for agricultural and domestic consumption. The bulk analysis on the water samples revealed that majority of the trace elements when compared with the World Health Organization (WHO) drinking water standards and Acme Laboratory Canada Method Detection Limits (MDL) have values that agree with the recommended limit. These findings show that the present status of groundwater in Iju is good for domestic and agricultural purposes. However, the presence of trace elements such as Lead, Bromide, Copper, Potassium, Manganese, Rubidium and Silicon in fairly high quantities in the groundwater samples which may be as a result of treatment in the water or dissolved salts in the groundwater may constitute major health hazards if not quickly checked. In spite of groundwater studies done in Ota, important information on groundwater resources in Iju is still largely unavailable. Thus, groundwater management can be effectively planned based on these results for the study area

A study of natural radioactivity in some building materials in Nigeria

Building materials of different brands were assessed for the concentrations of 226Ra, 232Th and 40K using HPGe detector. The activity concentrations in the measured samples ranged from 27 ± 8 to 82 ± 8 Bq kg−1 for 226Ra, 41 ± 4 to 101 ± 8 Bq kg−1 for 232Th and 140 ± 8 to 940 ± 19 Bq kg−1 for 40K, respectively. The Radium equivalent (Raeq) activity from the samples was found to be <370 Bq kg−1 as the recommended value for construction materials. This study will set a baseline data for significant standards on radiation exposure of the measured radionuclides in the selected building materials used in Nigeria