Alluvium Deposit Research Articles

Near surface resistivity investigation of regolith of Middle Benue Trough: implications on road pavement along Lafia-Shendam Axis, North Central Nigeria

ABSTRACT Electrical characteristics and subsurface structures associated with the regolith of Middle Benue Trough have been investigated. Vertical electrical sounding (VES) and constant separation traversing (CST) techniques were employed for data acquisition along Lafia-Shendam Road, Lafia, North Central Nigeria. Forty (40) Schlumberger sounding stations and four (4) Wenner resistivity profiles were occupied along opposite sides of the road to delineate and decipher the subsurface geological structures. Second-order Dar Zarrouk parameters (longitudinal and transverse resistivities, mean resistivity and coefficient of anisotropy) computed from VES parameters were also used to evaluate the pseudo-anisotropy characteristics of the regolith cover. Geoelectric sequences delineated within the study area include thin topsoil, alluvium deposit, weathered layer (laterite and saprolite) and fresh basement. The regolith is hosted by a weathered sedimentary rock at an average depth which varies from 10.2 to 37.3 m. The regolith structure is not complex and has a greater proportion of conductive laterite. The saprolite associated with the host sedimentary rock, masked in the VES technique, is revealed as a very thin zone with moderate resistivity in the CST 2-D structures. The predominance of laterite in the regolith is also corroborated by the range of values of the coefficient of anisotropy and mean resistivity.

Evaluation of physicochemical and microbiological parameters, and their correlation in Himalayan Spring Water Systems: A case study of District Kulgam of Kashmir Valley, India, Western Himalaya.

Total coliforms, E. coli, and fecal streptococci are the important indicators linked to the human health. This study investigated presence of these indicator bacteria in the Himalayan springs at various locations in the district Kulgam of Kashmir valley. A total of 30 spring water samples were collected from rural, urban, and forest areas during post-melting season 2021 and pre-melting season 2022. The springs in the area originate from the alluvium deposit, Karewa, and hard rock formations. The physicochemical parameters were found within the acceptable limits. However, nitrate and phosphate were found above the permissible limit at few sites, thus indicating the presence of anthropogenic activities in the area. Majority of the samples during both the seasons were found highly loaded with total coliforms with maximum limit of greater than 180 MPN/100ml. E. coli and fecal streptococci were found in the range of less than 1 to more than 180 MPN/100ml. The results of Pearson correlation of physicochemical parameters with indicator bacteria showed that chemical oxygen demand, rainfall, spring discharge, nitrate, and phosphate are the main factors affecting the concentration of indicator bacteria in the spring water at each site. Principal component analysis showed the most influencing factors of water quality in most of the spring sites are total coliforms, E. coli, fecal streptococci, rainfall, discharge, and chemical oxygen demand. The results of this study showed that the spring water is unfit for drinking purpose because of high concentration of fecal indicator bacteria.

Geotechnical Characterization of the Subsurface Using Seismic and Electrical Resistivity Techniques in Mikinduri Meru County, Kenya

Abstract Geotechnical study of the Mikinduri area was conducted with the aim to establish the causes of landslides and ground subsidence during the heavy rainfall. Sounding curves, travel time curves, 2D geoelectric sections, and 2D seismic models revealed 3-5 lithologic units to a depth of 30-250m. The study established thick loose alluvium deposits mixed with clay to a depth of 0.3-15m on an impermeable sub-basement as the possible major trigger of the landslides witnessed during rainy seasons. The thick alluvium deposits are due to erosion. They have been transferred by the location of the Mikinduri area, which lies in the lower regions of the Nyambene domes. Geologically, the domes were formed during Mount Kenya volcanic series and parasitic activities between the early Miocene and late Pleistocene eras. Resistivity modeling revealed deep geologic structures, including possible intrusions extending from 50m deep and faulted regions to a depth of 60-150m in the central and northeast area of study. The faulted area is highly saturated, as revealed by the low resistivity values. The delineated top black cotton soils and alluvium deposit are 40-50% clay and have poor foundation bearing capabilities. In contrast, compacted gravel, silt, and compact basaltic rock basement have good foundation capabilities. Keywords: Geotechnical, characterization, subsurface, seismic, electrical resistivity, foundation, geoelectric layer, Mikinduri Meru, Kenya.

Geoelectrical subsurface characterization: A case study of saltwater intrusion in Kudat, Sabah

Saltwater intrusion is one of the primary sources of groundwater contamination, especially near the coastal line, and it is crucial to monitor saltwater intrusion to protect fresh groundwater. Due to the proximity of the coastal line, the area within Kudat Peninsula that was formed by the ophiolite basement, Kudat Formation Chert-Spilite Formation, and alluvium deposit is susceptible to saltwater intrusion. In this study, two survey lines of geoelectrical resistivity and induced polarization imaging survey with a total length of 200 m were carried out. The Wenner configuration was used to characterize the subsurface of the Kudat Peninsula. The interpolation between geoelectrical resistivity and chargeability profiles provided better interpretations of the subsurface environment. The saltwater intrusion zone displays a resistivity value between 0 – 5.0 Ωm and a chargeability value between 0 – 3.0 ms. The results showed that saltwater intrusion was detected at depths as shallow as 1.25 m to 36.90 m and intruded as far as 218.00 m into the mainland, from the coastline.

Post-Earthquake groundwater potential analysis in Mamuju Regency, West Sulawesi

The earthquakes that occurred in January 2021 at Mamuju, West Sulawesi not only caused damage to buildings but also destruction of water facilities. Thus, question is raised about the changes of groundwater quality in the area. This study aims to follow up this question by conducting the geoelectric measurement, pumping test, and water quality analysis. Based on the resistivity values of geoelectrical data, each area has aquifers in different stratigraphic layers of (1) calcareous sandstone of the Mamuju Formation, (2) lapilli rock of the Gunung Api Adang Formation, (3) breccia of the Gunung Api Adang Formation and (4) sandstone of the Alluvium deposit. These aquifers are mainly confined and were grouped into the shallow (less than 25 m deep) and deep (more than 25 m deep) aquifers. Water quality from the groundwater wells meet the criteria of Environmental Health Quality Standards, except for one well GL03-PLDA that has high manganese content. Determined discharge values suggest that water resources are enough to support around 3916 people or 999 settlements in Mamuju District and about 11664 people or 2916 settlements in Simboro District.

Evaluation of iron ore deposit using 2D resistivity imaging and induced polarization technique at Fakarau Potiskum, Northeastern Nigeria

2D Electric resistivity imaging and Induced polarization (IP) techniques were used to evaluate Iron Ore deposit at Potiskum area of Yobe State, Northeastern Nigeria. The area lies between latitudes 110 40' 00'' and 110 50' 00'' N, and longitude 110 00' 00'' and 110 10' 00'' E. The survey was targeted at determining resistivity and chargeability values that are associated with the iron ore deposit. The dipole-dipole array was used for 2D resistivity and induced polarization imaging. Data processing and interpretation were done using RES2DINV software. This research had characterized the study area into two portions: the alluvium deposit that is highly enriched of iron ore and alluvium deposit with disseminated iron ore. The portion of the iron rich alluvium, characterized by low resistivity and chargeability of 32 Ωm to 734 Ωm and 0.403 msec to 3.400 msec are inferred as alluvium that is highly enrich with iron ore, while the portion that are respectively characterized by resistivity and chargeability values of 734 Ωm to 1418 Ωm and 1.90 msec to 6.40 msec are inferred as alluvium with disseminated iron ore. It can be concluded that the occurrence of iron ore deposit is probably more at northeast part of the survey area. The iron ore deposit strikes in the Northeast-Southwest direction.

Impact of Governing Factors on Prediction of Tunneling Induced Surface Settlement in Young Alluvium Deposit

Impact of Governing Factors on Prediction of Tunneling Induced Surface Settlement in Young Alluvium Deposit

Large strain dynamic characteristics of quaternary alluvium sand with emphasis on empirical pore water pressure generation model

The present study focuses on the cyclic behaviour of cohesionless soil collected from the quaternary alluvium deposit at the Middle Ganga Plain (MGP). A series of strain-controlled cyclic triaxial tests have been carried out on collected soil samples at various effective confining stresses, shear strain amplitudes and motion frequencies to estimate the dynamic parameter at large strain. From the results, it has been shown that dynamic properties and liquefaction strength substantially affected by the shear strain amplitude of input motion. However, effective confining stress and motion frequency have no significant effect on dynamic properties and liquefaction strength at large strain. Regression equations have been developed for dynamic and liquefaction strength parameters for the studied soil. It has been found that the consideration of asymmetricity in the shape of hysteresis loops significantly influences the damping ratio estimation at a particular shear strain. Another novel aspect that has been presented in this study is the effect of effective confining stress on the EPWP model parameter F using a mathematical equation. The regression equation for model parameter F proposed in this study has been validated by predicting the maximum EPWP development of studied soil and other quarternary alluvium soils available worldwide.

Salinity of paddy field in main landforms in Indramayu Regency, West Java

One of the main problems of paddy field in Indramayu is the high level of salinity. Paddy fields in Indramayu Regency are located around the North Coast. This area is dominated by the alluvial, fluvio-marine, and marine landforms groups. This study aims to examine the relationship between soil salinity and the type of landform. A total of 102 soil samples on paddy soils were taken and analyzed in the laboratory to obtain soil salinity data. The average of soil salinity value in each landform was compared with one another. Several litho-sequent transects were constructed to observe the pattern of salinity distribution and two soil profiles were observed to confirm the soil forming material. The soils in the marine landform group had the highest salinity, followed by the fluvio-marine and alluvial group, with a mean value was 390.6 mg.L-1, 141.0 mg.L-1, and 61.9 mg.L-1, respectively. The salinity of soils developed from marine deposit is higher than alluvium deposit. The closer distance to coastline makes the possibility of higher sea water intrusion, causing higher soil salinity. The landform approach in estimating soil salinity level is very useful, making it easier to find effective land management to reduce negative impacts on paddy field.

Assessment of lumped particles effect on dynamic behaviour of fine and medium grained sands

One novel aspect addressed here is the effect of the lumped particle on the dynamic behaviour of cohesionless soil. The effects of particle size and fines content on cyclic soil behaviour have been previously studied by mixing fine particles separately with cohesionless soil. The studied cohesionless soil in the quaternary alluvium deposit on Middle Ganga Plain in India contains a significant amount (10%–20%) of soil lumps. Therefore, the present study using strain-controlled cyclic triaxial tests addressed the effect of parameters mentioned above on the liquefaction resistance of sand where the fines were present in a lumped form. A series of undrained cyclic triaxial experiments have been performed on isotropically consolidated samples to quantify the effects of soil lumps present in various types of sand. Experimental results have shown less cyclic resistance for soil samples with lumps compared to clean sands of equivalent grain size. This is believed to be due to lumped particle crushing, and soil particle rearrangement during the sample saturation and loading. This affects dynamic properties such as shear modulus. From the results, it can be concluded that the presence of such soil lumps in cohesionless soil is reducing the initial shear modulus and the soil becomes more susceptible to liquefaction.

Geostatistical evaluation of spatial variability of land subsidence rates in Lagos, Nigeria

Accurate land subsidence prediction is fundamental for effective management of land subsidence and other associated geohazards. Lagos, the most densely populated city in Nigeria, has been adversely affected by widespread land subsidence. Previous studies have largely been restricted to analyzing space geodetic technique data. Unfortunately, this technique imposes spatial limitations resulting in incomplete coverage of the study areas due to atmospheric effects, orbital satellite characteristics, or surface characteristics. The application of geostatistics to georeferenced data obtained from space-based measurements can reliably provide complete information on spatial variability. The objective of this study is to provide an overview of current subsidence rates and to assess the spatial variability of land subsidence in the study area by using geostatistics that integrate semivariogram and ordinary kriging. The study area was partitioned into eight subregions; for each subregion, the experimental variogram was determined from the observed data and fitted to the optimal models. Seven subregions were fitted to exponential models and one was fitted to the spherical model. The model semivariograms were used in the kriging analysis to estimate the spatial variability of subsidence rates. The results showed that the nugget-to-sill ratio lies between 44 and 70%, indicating that the spatial variation of subsidence rates at the scale under study is moderately distributed and the mechanism of deformation is similar. The nugget effect of the subsidence rate is between 0.25 and 0.75, indicating that subsidence rates are influenced by various contributions. The predicted spatial variability of subsidence rates by Ordinary Kriging presents reliable values of R-squared (0.32–0.42) and RMSE (0.21–0.30). Critical subsidence rates characterised the areas around the Atlantic Ocean coastal alluvium deposit, the Lagos lagoon, and the Ogun River flood alluvium. This study successfully demonstrates the suitability of the geostatistical tools to evaluate spatial variability of subsidence rates.

Seismic Behaviour of RC Building with Raft Foundation in the Ganges Basin, India

Many highly populated and important cities of India are situated in the Ganges basin. Deep alluvium deposit of this basin enhances the earthquake vulnerability of these cities due to amplification of seismic energies in the case of an earthquake. Raft foundations are generally provided for critical facility buildings due to their perceived effectiveness against differential settlement during earthquakes. However, the literature available on seismic behaviour of buildings with raft foundation considering soil deformability is relatively limited. In this context, a full three-dimensional finite element model of a four-storeyed building with raft foundation considering the typical layered soil profile of the Ganges basin has been developed in this study. The effects of different seismic parameters on the structural responses and moments induced in the raft have been studied with ground motions from 10 different earthquakes. Since the alluvium deposit of the Ganges basin is prone to get liquefied, effects of liquefaction of soil on the building with raft foundation have been considered simplistically. The results show that the raft foundation reduces the lateral displacement of the structure considerably. However, an increase in the vertical settlement of the raft in case of liquefiable soil is a matter of concern.

Fluctuation of Citrobacter Transport Influenced by High Porous Medium in Homogeneous Silty Formation in Saline Environment

This paper monitor the deposition of Citrobacter in high porous medium in saline environment, the study investigate the behaviour of the contaminant in saline environment, the application of deterministic model developed simulation values that express the behaviour and effect from high porous medium, such shallow phreatic bed were observed to experiences fluctuation in soil porosity thus reflecting on the rate of concentration. The simulation developed locations that the concentration generated fluctuation to the depth were it was in significant in the formation, this was observed to be in an area were Citrobacter experiences degradation due to lack of microelement for growth. Moreso its deposition in shallow Phreatic zone has evaluated the rate of transport with respect to time and depth from the study carried out, it was observed to be predominantly influenced by high porosity in the formation, the influences of alluvium deposit in these condition could not influences the aquiferous zone by uniformity of the Phreatic deposited strata. Formation characteristics stated above were found significant in the migration of Citrobacter from surface to phreatic zone. The models were simulated and it produced theoretical values compared with other measured results, both parameters developed a favuorable fits validating the model.

Spatial delineation of riparian groundwater within alluvium deposit of mountainous region using Laplace equation

AbstractThe interaction between surface and groundwater plays a key role in a riparian ecosystem while the size of riparian groundwater has not been typically incorporated into hydrological modelling systems. An extensive geophysical survey composed of 25 individual DC electrical resistivity profiles was conducted at the Blair–Wallis site in Wyoming. The observed resistivity images show a near‐surface aquifer interpreted as the saturated alluvium deposit along the channel, rather than the geological bedrock. Based on the electrical resistivity images, it can be inferred that only the near‐surface portion of the groundwater actively interacts with the stream flow in the mountainous and hilly watershed. This study attempted the spatial extrapolation of the measured riparian aquifer depths by means of fitting functions based on the surface topography. The analysis indicated that the boundary of the riparian aquifer well corresponds to the topographical inflexion point of the hill slope profile. It was also demonstrated that the extent of alluvium deposit, where the area of riparian aquifer is indicated, can be delineated using the slope and curvature maps in the geographic information system. Then, the parabolic and biharmonic functions were tested for the groundwater depth estimation using the developed alluvium deposit map. The proposed methodology was effective if geological diffusion processes by wind and water dominated the topography. The spatial map of the active aquifer will be useful in hydrological drought analysis because it is considered to be a main source of baseflow during dry seasons.

Fracture controlling of vertical shaft lining using grouting into neighboring soil deposits: A case study

Vertical shaft lining (VSL), which usually performs asa place for shaft sets to bolt into and a smooth surface to minimize resistance to airflow for ventilation, is one of the important approaches to gain access to underground coal seam. Extensive fracturing phenomenon of VSL were uniquely observed in Southeastern China due to the rapid increase of negative skin friction (NSF) from continuous settlement of thick soil deposits. Compaction grouting into these soil deposits was utilized to reduce the existing strain in fractured VSL, thus controlling the fracture development. And the efficacy of grouting was quantitativelyinterpreted via the strain variation in VSL and VSL rise comprehensively. The results showed that the strain as well as the elevation of VSL presents perfect increasing, decreasing, and then increasing characteristics correspondent to the grouting, grouting intermission, and re-grouting respectively. Further, the maximum released strain εmaxre induced from grouting accounts for over 50% of the accumulated strain εbgac, with the maximum VSL rise making up over 25% of the VSL settlement. These significant observations identify that the method of using grouting to stabilize and strengthen fractured VSL works well under such special strata. The capability and reliability of this method make it attractive in controlling of fractured VSL constructed in thick alluvium deposit.

Characterization of Thin Alluvial Bed Aquifers in Manggar River Balikpapan East Kalimantan Indonesia

Abstract Manggar Village is suburban, located in District of East Balikpapan, East Borneo Indonesia. In dry season, clean water crisis always hit this area. Therefore in order to full fill the need of water for domestic use the inhabitant of this area use dug well water. Dug well water comes from the upper most ground water that is stored and transmitted by relatively thin layer of alluvium deposit. In this research surface elevation measurement was done to control the elevation of dug well so that the depth of dynamic water level ( DWL ) could be determined accurately. The equipotential map was made based on the DWL , then flow line can be drawn and gradient hydraulics ( i ) can be calculated. Coefficient of permeability ( k ) that were resulted from fall head test has shown value 1.284 x 10 -3 up to 11.45 x 10 -3 cm/sec which gradually increases toward beach. According to the results of serial test and calculation the ground water transmissibility and velocity increases toward the beach. Generally groundwater has high hardness. The groundwater close to the beach has been mixed with sea water.

Stable Isotopes and Hydrochemistry Approach for Determining the Salinization Pattern of Shallow Groundwater in Alluvium Deposit Semarang, Central Java

DOI: 10.17014/ijog.4.1.1-10A groundwater study has been conducted in the Semarang City in August 2014, aiming to determine the source of shallow groundwater salinization using stable isotopes (18O, 2H) and water chemistry approach, and supported by local hydrogeological data. A number of shallow groundwater samples were taken at several locations with a depth of 0 - 35 m. Based on geological data, shallow groundwater of Semarang alluvium is dominated by insertion of sand-gravel and sandy-clay with average porosity of around 56.0 %. This layer is thinning towards the south and then increasingly thickening to the north and north-east of the studied area. The results of the analyses show that the characteristics of shallow groundwater, i.e. approximately 51% of groundwater, still have the original composition as meteoric water and the remaining approximately 49% obtained a shift in the isotopic composition as caused by interaction with seawater and the little influence of evaporation. The results of chemical analysis of water indicates that in dry seasons, shallow groundwater aquifers in the Semarang City is dominated by chloride (Cl-) with NaCl of water type. While the parameters of bicarbonate, chloride, and Na/Cl ratio, shallow groundwater can be classified into two groups, namely unintruded groundwater around 51% spread from the foot hills to the south towards the hills with elevations of 9 - 142 m above sea level and intruded groundwater around 49% spread from the coastline to the urban direction.

Permanent Deformation Characteristics of Concrete Face Rockfill Dams on Alluvium Deposit Subjected to Different Strong Seismic Excitations

Using seismic analysis theory of CFRD, the numerical calculation of dynamic response of a high CFRD on alluvium deposit in strong earthquake zone subjected to strong seismic excitations of different transcendental probabilities was carried out, with emphasis on the seismic safety evaluation by permanent deformation. The influence of dynamic mechanical properties of the alluvium deposit on the dam's permanent deformation was also analyzed. The results show that permanent deformation will increase gradually with the increasing of peak value of seismic acceleration. The seismic safety of dam is in a normal range under the earthquake with transcendental probability of 2% in 100 years. The alluvium deposit has significant influence on the dam's dynamic response.

Dynamic Interaction between Reservoir and a High Concrete Face Rockfill Dam on Deep Alluvium Deposit

Potential-based fluid model and Westergaard added mass model were used to reflect the dynamic interaction of reservoir-CFRD(concrete face rockfill dam)-foundation coupling system. The deep alluvium deposit was treated as porous medium using Biot's dynamic consolidation theory. In the coupled analysis, the paper focused on hydrodynamic pressures in the reservoir zone, dynamic response and pore water pressure in the structure zone. The result shows that the dynamic response of added mass model is greater than that of potential-based fluid model. The porous medium of alluvium deposit is of great significance in performing soil liquefaction analysis and reservoir-dam-foundation system.

Soil responses near Delhi ridge and adjacent regions in Greater Delhi during incidence of a local earthquake

In this study, soil response was carried out for the Greater Delhi region. A folded Proterozoic formation was identified as Delhi ridge, passes through its central part along SSW–NNE direction, and appears to be a main geomorphic feature for the study area. The Delhi ridge is an exposed quartzite rock of about 10–100 m wide and ~25 km long with gentler dipping both toward east and west. We have considered the exposed part as an outcrop side near the ridge axis and the dipping area as rigid base away from the ridge axis for ground motion study during the occurrence of the 25 November 2007 earthquake with magnitude ML 4.3 (Richter scale) that occurred at Delhi–Haryana State boundary. The degree of shaking was very strong and reported major cracks in the buildings near the epicenter area. We have studied the soil response parameters at the surface level, considering horizontally stratified soil layers above rigid base. The equivalent linear method was used for soil response analysis at 25 sites in Greater Delhi area. The peak amplification factors vary from 3.2 to 5.9 and peak resonance frequency varies from 1.2 to 5.3 Hz. The correlation among the peak amplification factor (A) and frequency (f) was empirically established as A = 0.36f + 3.60. Increasing peak amplification factor was found at sites with increasingly thicker alluvium deposit with lower frequency contains ground motion and vice versa. Seismic zoning map was also reconstructed for peak amplification factors and predominant periods for the study area for the mitigation purposes of earthquake damage. The average shear wave velocity up to 30 m soil depth is also obtained for site classification. The average velocity to 30 m [\( \overline{{V_{\text{s}} }} (30) \)] is a widely used parameter for classifying sites for predicting their potentiality to amplify seismic shaking. A lower value [\( \overline{{V_{\text{s}} }} (30) \)] thus yields a more conservative estimate of ground motion, which generally increases as \( \overline{{V_{\text{s}} }} (30) \)decreases. Present estimate of \( \overline{{V_{\text{s}} }} (30) \)varies from 315 to 419 m/s. In this study, we have identified two site classes C and D, as per National Earthquake Hazard Reduction Program. The city planner or engineers can directly use these data for site-specific assessment during retrofitting of the existing structure, demolition of the old buildings and design a new structure to avoid major destruction of the buildings due to future earthquake.