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Geotechnical Properties of Subsurface Soils in Warri, Western Niger Delta, Nigeria

TL;DR: In this article, the authors used integrated surface electrical resistivity survey, borehole drilling and insitu testing by CPT to determine engineering geological properties of soils underlying Warri metropolis for the planning and design of civil engineering structures.
Abstract: Integrated surface electrical resistivity survey, borehole drilling and insitu testing by CPT were used to determine engineering geological properties of soils underlying Warri metropolis for the planning and design of civil engineering structures. Results revealed that three major sub-soil types underlie the area characterized by dry, swampy and marshy ground conditions. These soils occur in the dry plains and swampy areas, from top to bottom, as silty sand, clayey sand and sand. However in the marshy NPA area, only two soil layers occur: the top 6m thick organic clay layer overlying the sand layer. The geotechnical properties suggest that all the layers can support structural loads from civil structures, provided foundation design is preceded by adequate subsoil investigation to provide construction specific data.

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Citations
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Journal Article
TL;DR: Different geotechnical properties of soils such as specific gravity, density index, consistency limits, particle size analysis, compaction, consolidation, permeability and shear strength and their interactions and applications for the purpose of civil engineering structures have been discussed as discussed by the authors.
Abstract: The occurrence and distribution of soils in nature varies from location to location. The type of soil depends on the rock type, its mineral constituents and the climatic regime of the area. Soils are used as construction materials or the civil engineering structures are founded in or on the surface of the earth. Geotechnical properties of soils influence the stability of civil engineering structures. Most of the geotechnical properties of soils influence to each other. In this paper, different geotechnical properties of soils such as specific gravity, density index, consistency limits, particle size analysis, compaction, consolidation, permeability and shear strength and their interactions and applications for the purpose of civil engineering structures have been discussed.

58 citations

Journal ArticleDOI
TL;DR: In this article, three (3) geotechnical boreholes were drilled at Akenfa in Yenagoa, Bayelsa Local Government Area of Nigeria and the results showed that the samples are low to medium plasticity silty clay.
Abstract: This study aims at establishing the sub-soil types and profile to ascertain the geotechnical characteristics of the underlying soils in Akenfa in Yenagoa, Yenagoa Local Government Area of Bayelsa State, Nigeria and recommend appropriate foundation design and construction of projects in the area. Three (3) geotechnical boreholes were drilled at the site to obtain baseline data on geotechnical properties of the soil and water level monitoring, the boreholes were advanced with the use of a cable percussion boring rig and were terminated to a maximum depth of 30m. The particle size distributions of a number of representative samples of the cohesionless soils were determined by sieve analysis. The results show that the samples are low to medium plasticity silty clay. The lithology revealed intercalations of clay and sand in thin layers to a depth of 2.0 m below the existing ground level. Underlying this clay is a stratum of loose to medium dense sand and dense sand. The sand is well sorted grading from fine to medium as the borehole advances. The laboratory analysis showed that the silty clay has undrained shear strength of 48 kPa. The loose sand has a maximum SPT (N) value of 12 while the medium dense sand has maximum SPT (N) value of 28. Considering the nature of the civil structures to be sited in the area, it is anticipated the load and the moderate compressibility of this near surface silty clay and the underlying loose silty sand be supported by means of raft foundation founded within the clay layer. It is recommended that studies on the geotechnical characteristics of the area be carried out as it provides valuable data that can be used for foundation design and other forms of construction for civil engineering structures in order to minimize adverse effects and prevention of post construction problems.

15 citations

Journal ArticleDOI
TL;DR: In this article, the authors used 3D seismic data and well information to assess the basin's potential for carbon capture and storage (CCS) in the Niger Delta region, showing that the presence of excellent reservoir-seal pair, very large basin size, suitable reservoir depth, matured oil and gas fields, moderate faulting intensity, availability of giant hydrocarbon fields and being a passive margin generally makes the Niger delta basin excellent environment for CCS.

8 citations

DOI
25 Dec 2018
TL;DR: In this paper, a pre-construction site investigation was carried out in a marshy stream channel and adjoining areas for a proposed building site to characterize the subsurface subgrades and recommend foundation design for which proposed structures include a 1-floor 39.7m x 33.6m hostel, a 20.5m x 10.0m 4-bedroom duplex and a 1 -floor 2-bedroom block of flats measuring 28.2m x 11.5 m with 1.5tons mechanical cone penetrometer.
Abstract: A pre-construction site investigation was carried out in a marshy stream channel and adjoining areas for a proposed building site to characterize the subsurface subgrades and recommend foundation design for which proposed structures include a 1-floor 39.7m x 33.7m hostel, a 20.5m x 10.0m 4-bedroom duplex and a 1- floor 2-bedroom block of flats measuring 28.2m x 11.5m with 1.5 factored design dead + live load data as 2700tons, 655tons and 1270 tons respectively. Field investigations include boring of 10 boreholes to a depth of 10m using auger and sounding of 6 cone penetration tests using a 2.5tons mechanical cone penetrometer. The results indicate a soft clay layer existing from ground surface to a depth varying from 1.0m – 1.1m in the stream channel and 0.60m – 0.70m on the adjoining land. These clays are extra-sensitive to sensitive high compressibility Kaolin clays (CH – OH, MH - OH) with undrained shear strength varying from 42 – 75.0KN/m2, angle of internal friction ranging from 0 - 30 with cone resistance values of 3.0 – 11.0 Kg/cm2. Swell potential ranges from 11.45 – 30.64%, swell index from 0.44 – 0.57, activity from 7.0 – 11.0 and swelling pressure 4.776KPa – 4.890KPa. Below this depth a harder clay layer occurs to a depth of between 4.5m – 5.2m and is proposed to found the structures. Pre-consolidation pressures determined from Oedometer test on undisturbed clay samples retrieved from the centre of the second clay layer varies from 125.0KPa – 162.5KPa and Overconsolidation ratios from 2.75 – 6.40 depicting overconsolidation while water table corrected bearing capacities indicates a favourable fully compensated depth of 1.2m for the building foundations. However excessive total settlement determined using Boussinesq’s average vertical stress ranges from 180.1cm - 211.1cm on adjoining land and 160 -111.9cm on the stream channel under the worst case scenario for the structures necessitating further depth compensation to 2.0m. This yielded a reduction in settlement varying from 8.0% to 9.9% on the stream channel and 16.7% - 18.4% on the adjoining land. Rate of settlement depicts that it will take 6.655 and 28.65 years after construction to achieve 50% and 90% settlement under the worst case scenario. Below these clays are loose to medium density sands of varying grain sizes. Load transfer to these sands through pile foundations was considered using the cone penetrometer as a load test to derive unit toe bearing capacities of piles which embedment depth of 11.0m was recommended.

6 citations


Cites background from "Geotechnical Properties of Subsurfa..."

  • ...0 x 10cm/sec which indicates a potentially productive aquifer [18, 8]....

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01 Jan 2014
TL;DR: In this paper, the sub-soil types and profile of the underlying soils in a site in D/Line, Port Harcourt, Nigeria for appropriate foundation design considerations for infrastructural development purposes in the area.
Abstract: The study aims at characterizing the sub-soil types and profile to ascertain the geotechnical properties of the underlying soils in a site in D/Line, Port Harcourt, Nigeria for appropriate foundation design considerations for infrastructural development purposes in the area. Borings were accomplished using a percussion rig with the aid of augers. Representative samples were analyzed in the laboratory in accordance with relevant geotechnical engineering standards. The study revealed that the surface is underlain by a soft – firm sandy clay (about 6m ) of moderate-high compressibility with undrained Strength of 46KN/m 2 overlying a firm-stiff sandy layer. Beneath these layers, are loose sandy layers (with an angle of friction, of 29 o ) overlying a medium dense sandy layer (with an angle of friction of 31 o ). Underlying these layers is a dense sandy layer (with an angle of friction of 36 o ). The allowable bearing capacity profile of the sub-surface shows low bearing capacities characteristics (1m - 2m: <110KN/m 2 ). These values are relatively lower than the projected foundation loading. Pile driven to at least 5m into the sand layer is recommended as the foundation option for consideration for civil engineering structures in the study area.

5 citations

References
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Journal ArticleDOI
TL;DR: In this paper, a new threefold lithostratigraphic subdivision for the Niger delta subsurface is introduced, comprising an upper sandy Benin Formation, an intervening unit of alternating sandstone and shale named the Agbada Formation, and a lower shaly Akata Formation.
Abstract: The coastal sedimentary basin of Nigeria has been the scene of three depositional cycles. The first began with a marine incursion in the middle Cretaceous and was terminated by a mild folding phase in Santonian time. The second included the growth of a proto-Niger delta during the Late Cretaceous and ended in a major Paleocene marine transgression. The third cycle, from Eocene to Recent, marked the continuous growth of the main Niger delta. A new threefold lithostratigraphic subdivision is introduced for the Niger delta subsurface, comprising an upper sandy Benin Formation, an intervening unit of alternating sandstone and shale named the Agbada Formation, and a lower shaly Akata Formation. These three units extend across the whole delta and each ranges in age from early T rtiary to Recent. They are related to the present outcrops and environments of deposition. A separate member of the Benin Formation is recognized in the Port Harcourt area. This is the Afam Clay Member, which is interpreted to be an ancient valley fill formed in Miocene sediments. Subsurface structures are described as resulting from movement under the influence of gravity and their distribution is related to growth stages of the delta. Rollover anticlines in front of growth faults form the main objectives of oil exploration, the hydrocarbons being found in sandstone reservoirs of the Agbada Formation.

1,036 citations

Journal ArticleDOI
TL;DR: A study of the engineering geological properties, distribution and classification of the major superficial soils of the Niger Delta was carried out as part of a study programme to provide the much needed information and data for the infrastructural development of the region as discussed by the authors.

67 citations


"Geotechnical Properties of Subsurfa..." refers background or methods or result in this paper

  • ...The Akata Formation forms the basal unit of the Niger Delta stratigraphic sequence and consists of an open marine facies unit dominated by high-pressured carbonaceous shales....

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  • ...Warri is located in the western portion of the Niger Delta (Figure 1) some 40 kilometers away from the shores of the Atlantic Ocean....

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  • ...This formation is oil-reservoir of the Niger Delta Basin....

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  • ...The western Niger Delta is the area that lies west of the Nun River and is geographically defined by Delta, Edo, and parts of Bayelsa States....

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  • ...3 Corresponding author, Department of Geology, University of Port Harcourt, Nigeria. available (Akpokodje 1989 [1], Abam and Okogbue 1997 [2], Teme 2002 [3], Tse 2006 [4], Onyebolise, and Akpokodje 2008 [5], Ugbe 2011 [6], Youdeowei and Nwankwoala 2011 [7], Tse and Akpokodje 2010 [8]) compared to paucity of data on the soils in western Niger Delta....

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Journal ArticleDOI
TL;DR: In this article, the Niger delta can be divided into three different zones, each with quite dissimilar stratigraphic and geotechnical characteristics: (i) sandy/clayey subsoil strata of the dry, flat plains; (ii) two-layer clay sand sequence of the fresh/salt water swamps; and (iii) three-layer, sand-clay-sand sequence of coastal beaches/ridges.

20 citations


"Geotechnical Properties of Subsurfa..." refers background in this paper

  • ...available (Akpokodje 1989 [1], Abam and Okogbue 1997 [2], Teme 2002 [3], Tse 2006 [4], Onyebolise, and Akpokodje 2008 [5], Ugbe 2011 [6], Youdeowei and Nwankwoala 2011 [7], Tse and Akpokodje 2010 [8]) compared to paucity of data on the soils in western Niger Delta....

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  • ...3 Corresponding author, Department of Geology, University of Port Harcourt, Nigeria. available (Akpokodje 1989 [1], Abam and Okogbue 1997 [2], Teme 2002 [3], Tse 2006 [4], Onyebolise, and Akpokodje 2008 [5], Ugbe 2011 [6], Youdeowei and Nwankwoala 2011 [7], Tse and Akpokodje 2010 [8]) compared to…...

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Journal Article
TL;DR: In this article, samples of deltaic lateritic soils were subjected to mechanical (with or without controlled sand addition), cement and cement-sand (composite) stabilisation methods to improve strength for improved engineering applications.
Abstract: Deltaic laterite is the most suitable and most widely used soil material for road embankment in the Niger Delta. Usually, its natural characteristics fall short of the minimum requirements for such applications hence it has to be stabilised to improve its properties. In this study, samples of deltaic lateritic soils were subjected to mechanical (with or without controlled sand addition), cement and cement-sand (composite) stabilisation methods to improve strength for improved engineering applications. Mechanical stabilisation was found to satisfy subgrade requirements while the addition of sand produced sub-base material quality at best depending on compacted maximum dry density (MDD), which itself is dependent on the optimum sand content (OSC). The OSC was also shown to affect the optimum moisture content (OMC) and the soaked California bearing ratio (CBR) of stabilised specimens. Combination of the test results produced a graphical model to predict the influence of mechanical stabilisation on the soil materials using the percentage fines (that is, passing through a 75 mm sieve) obtainable from wet sieving. Cement stabilisation of the soil (by indigenous highway standard) produced base-course quality materials with cement content in excess of 12 %, which is economically unviable. However, the addition of controlled proportions of sharp sand (also abundant in the Niger Delta) to the soilcement mixtures produced base-course quality materials with 6 % cement (less than half of that obtained through only cement stabilisation) and about 40 % sand content. A model was also presented to predict the other constituents of sand-cement stabilisation using the percentage fines obtainable from wet sieving.

8 citations


"Geotechnical Properties of Subsurfa..." refers methods in this paper

  • ...Such stabilization methods are mainly mechanical and chemical stabilization as suggested by Akpokodje (1986) [16] and Omotosho and Eze-Uzomaka (2008) [17]....

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Journal ArticleDOI
TL;DR: In this article, a sub-surface investigation was performed by drilling boreholes within and along the Nun River Channel covering three communities of Kaiama, Opokuma and Sabagreia, Bayelsa State, Nigeria.
Abstract: Sub-surface investigation was undertaken by drilling boreholes within and along the Nun River Channel covering three communities of Kaiama, Opokuma and Sabagreia, Bayelsa State, Nigeria. The route extent was over 5 km long and the study was necessitated to provide materials as structural fills for road construction purposes. Eight boreholes were drilled in the three locations to a maximum depth of 14 m from the river bed. Results reveal an overlying ligh grey to dark brown, very fine grained (anhedral), soft to stiff consistency, highly plastic silty clay soil in all the boreholes. This unit varies in depth vary in depth of 1.0 to 7.0 m and is proceeding thinner towards the Sabagreia axis from Kaiama. Beneath this overburden lie light grey, medium grained sands, in BH 2 to BH 6 covering the Kaiama and Opokuma axis. The sands are about 7 to 12 m in thickness to the maximum drilled depth of 14 m. In BH 7 and BH 8 in the Sabagreia axis, the underlying sands are coarse grained in texture and about 13 in thickness to the borehole depth. It is recommended that the sand may be derived at minimum depths of about 1.0 m below the river bed in the Sabagreia area, about 2.0 m in the Opokuma region and about 4.5 to 7.0 at the Kaiama axis. Medium to coarse grained; poorly graded (well sorted) sands which display uniform size gradation in the sand range were encountered below the river bed in the area. Key words: Soils, grain size, engineering properties, stratigraphy, Niger Delta.

4 citations


"Geotechnical Properties of Subsurfa..." refers result in this paper

  • ...…of Port Harcourt, Nigeria. available (Akpokodje 1989 [1], Abam and Okogbue 1997 [2], Teme 2002 [3], Tse 2006 [4], Onyebolise, and Akpokodje 2008 [5], Ugbe 2011 [6], Youdeowei and Nwankwoala 2011 [7], Tse and Akpokodje 2010 [8]) compared to paucity of data on the soils in western Niger Delta....

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