scholarly journals Engineering Subsoil Characterization for Shallow Foundation Design in Ode Irele Area of Ondo State, Southwestern Nigeria

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Olumuyiwa O. Falowo ◽  
Michael B. Amodu
Keyword(s):  
Bearing Capacity ◽  
Shallow Foundation ◽  
Soil Conditions ◽  
Cone Penetration ◽  
Foundation Design ◽  
Southwestern Nigeria ◽  
Foundation Soil ◽  
Geotechnical Investigations ◽  
Allowable Bearing Capacity ◽  
Coastal Sand

Integrated geophysical and geotechnical investigations for foundation design have proved to be good veritable tools in effective foundation design and construction. Geophysical and geotechnical methods involving electrical resistivity and cone penetration test have been carried out to investigate the foundation soil conditions of Ode Irele, southwestern Nigeria. Six vertical electrical sounding (VES) were carried out along two traverses; which is complemented by two cone penetration tests with seven trial tests at different subsurface depths. The geotechnical results showed that the soils are sand and silt dominated. All the tested parameters fall within the Nigeria federal ministry of works and housing specification with liquid limit (< 50%), plastic limit (< 30%), plasticity index (< 20%). The geoelectric sections identified maximum of six geoelectric/geologic subsurface layers comprising the topsoil (red sand), weathered layer (made up of coastal sand/white sand), clayey sand (which is the major aquitard in the area), intermediate sand aquifer unit. However the coastal sand layer has moderately high resistivity at shallow depth to sustain foundation load with thickness greater than 2 m. The groundwater level measured from existing borehole records 17.5 m which may not or seriously affect the bases of the foundation footing. Consequently an average allowable bearing capacity of 150 KN/m2 (ultimate bearing capacity of 450 KN/m2) would be appropriate for design of shallow foundation in the area, at a depth not less than 1.6 m in Ode Irele and 0.8 m at Ajagba. The foundation width of 0.6 m would produce minimum bearing settlement less than 25 mm. The appropriate (recommended) ultimate bearing and allowable bearing capacity for strip and square footings at depth levels of 0.6 – 1.2 m vary from 1486 – 1842 KN/m2 and 495 - 614 KN/m2; and 2056 – 2489 KN/m2 and 685 - 830 KN/m2 respectively.

scholarly journals Engineering Site Investigation for Foundation Design and Construction in Shale and Sandstone Derived Soils of Okitipupa Area, Southwestern Nigeria

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
FALOWO OLUSOLA OLUMUYIWA
Keyword(s):  
Site Investigation ◽  
Shallow Foundation ◽  
Cone Penetration ◽  
Foundation Design ◽  
Deep Foundation ◽  
Southwestern Nigeria ◽  
Building Foundation ◽  
Allowable Bearing Capacity ◽  
Engineering Standards ◽  
Electrical Soundings

Geotechnical and geo-electrical investigations of Okitipupa has been carried out with the major objectives of establishing the subsoil/geology, evaluate the geotechnical properties and recommend appropriate foundation alternatives for building foundation construction. Seven borings were carried out with hand auger at two cone penetration test locations, and representative samples were collected and analyzed in the laboratory in accordance with relevant geotechnical engineering standards. In addition, six vertical electrical soundings (VES) were also conducted using Schlumberger configuration. The result of VES delineates three major geologic sequence comprising the topsoil/caprock, sand surficial aquifer, and sand intermediate aquifer. The topsoil has resistivity range of 242 – 1503 ohm-m and thickness of 3.4 - 20.9 m composed of clay sand and sand. This layer is capable of supporting shallow foundation such as simple spread, raft of reinforced concrete, with recommended allowable bearing pressure of 100 KN/m2 at depths of 1.0 m and 3.2 m in the northern and southern part of the study area respectively. The estimated settlement are less than 50 mm using foundation width of 0.6 m, but could be reduced by almost 50% if the width is greater than or equal to 2 m. The groundwater level is very deep (>10 m) and may not likely threatens the integrity of the foundation structures. The estimated allowable bearing capacity for strip footing (203 – 980 KN/m2), square footing (608 – 2940 KN/m2) within 1.4 m depth is appropriate. The capacity of driven (deep foundation) circular piles of diameters 400mm, 500mm, and 600mm, the recommended pile capacity varies at depth of 5 m (69 – 124 KN), 10 m (225 – 378 KN), and 15 m (470 – 766 KN), while that of bored circular pile ranges from (36 – 75 KN), 10 m (93 – 180 KN), and 15 m (170 – 317 KN).

scholarly journals Subsoil Engineering Characterization and Foundation Design in Derived Geological Coastal Sands of Ilaje Area of Ondo State, Nigeria

2020 ◽  
pp. 458-468
Keyword(s):  
Bearing Capacity ◽  
Shallow Foundation ◽  
High Resistivity ◽  
Building Structures ◽  
Cone Penetration ◽  
Foundation Design ◽  
Geotechnical Parameters ◽  
Design Alternatives ◽  
Allowable Bearing Capacity ◽  
Ondo State

Engineering subsoil evaluation and foundation design have been undertaken at Ilaje area of Ondo State, Nigeria. The aim of this study was to examine the geo-electrical and geotechnical parameters of the subsoil to sustain building structures and also provide appropriate foundation design alternatives. A total of six VES stations were occupied and complemented with geotechnical analysis of seven soil samples collected at two cone penetration test locations. The result showed that all the determined geotechnical parameters of the subsoil fall within the specification recommended for foundation material by federal ministry of works and housing of Nigeria. The VES showed a predominant (66.67%) HKQ curve type. The upper 5 m is characterized by moderate thickness and high resistivity (average of 450ohm-m) values to sustain structural load. An average allowable bearing capacity of 150 KN/m2 was recommended for design of bases/footings for shallow foundation at a depth not less than 1.0 m. The obtained settlement values are less than 50 mm and within tolerable limit, for foundation width ranging from 0.5 to 3.0 m. However there was drastic reduction in settlement values (below 25mm) when the foundation width was increased to 2 and 3m. The allowable capacity of the driven pile ranges from 64 – 115 KN, 206 – 347 KN, and 418 – 677 KN at 5m, 10 m and 15 m respectively. The allowable bearing capacity for bored piles ranges from 34 – 69 KN, 85 – 165 KN, and 146 – 268 at depth levels of 5 m, 10 m, and 15 m respectively.

scholarly journals Engineering Site Investigation and Shallow Foundation Design in Ore Area of Ondo State, Nigeria

2020 ◽  
Vol 67 (1) ◽  
pp. 21-33
Author(s):  
O. Falowo Olumuyiwa
Keyword(s):  
Bearing Capacity ◽  
Soil Analysis ◽  
Site Investigation ◽  
Shallow Foundation ◽  
Cone Penetration ◽  
Foundation Design ◽  
Overburden Thickness ◽  
Allowable Bearing Capacity ◽  
Weathered Layer ◽  
Electrical Sounding

AbstractThe study integrates geophysical and geotechnical methods for subsoil evaluation and shallow foundation design. The study involved six vertical electrical sounding and geotechnical investigation involving cone penetration test and laboratory soil analysis. Three major geologic units were delineated; the topsoil, weathered layer and partly weathered/fractured/fresh bedrock. The overburden thickness is in between 15.2–32.9 m. Based on resistivity (16–890 ohm-m) and thickness (12.7–32 m) the weathered layer is competent to distribute structural load to underlying soil/rock. The groundwater level varies from 4.5 to 12.3 m. Therefore an average allowable bearing capacity of 200 kPa is recommended and would be appropriate for design of shallow foundation in the area, at a depth not less than 1.0 m with an expected settlement ranging from 9.03–48.20 mm. The ultimate bearing and allowable bearing capacity for depth levels of 1–3 m vary from 1403–2666 kPa and 468–889 kPa for strip footing while square footing varies in between 1956–3489 kPa and 652–1163 kPa respectively.

scholarly journals Geophysical and Geotechnical Investigation of Building Failure in A Typical Basement Complex Environment – A Case Study in Ile-Ife, Nigeria

2021 ◽  
Author(s):  
Olaolu Afolabi ◽  
Ayoola Temiloluwa Oladeji ◽  
Babatunde Moruf Salami ◽  
Sadiq Akorede Lawal
Keyword(s):  
Electrical Resistivity ◽  
Basal Layer ◽  
Shallow Foundation ◽  
Cone Penetration ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Foundation Soil ◽  
Resistivity Method ◽  
Weathered Layer ◽  
Electrical Resistivity Method

Abstract A building located within the Basement Complex of the ancient town of Ile – Ife, Osun State, Southwestern Nigeria was observed to have failed due to excessive total and differential settlement. The failure was investigated using the electrical resistivity and geotechnical methods The electrical resistivity method involved the 2-D electrical resistivity imaging (ERI) technique using the dipole-dipole array along four traverses of 30 – 60 m in lengths. The geotechnical method involved the cone penetration test (CPT) using the 2.5-ton static penetrometer machine. Quantitative and qualitative analysis of the ERI data were made using the DIPROfWIN software for the pseudo-inversion while the CPT data were interpreted for lithology using standard chart. The results show that the topsoil, about 1.0 m thick, is composed of sandy clay/clay that is characterized by cone resistance (qc) of 0.2 – 2.0 MPa and resistivity of 75 - 200 Ωmm. The underlying clayey weathered layer, which constitute the shallow foundation soil is characterized by thickness of 4 - >10 m, qc of 0.2 – 1.0 MPa, resistivity of 25 - 75 Ωmm and estimated consolidation settlement of 200 – 500 mm. The basal layer is the saprock/fresh bedrock characterized by qc of > 8.0 MPa and resistivity of 100 - 1000 Ωmm. The subsoil is thus characterized by variably thick incompetent clayey weathered layer within which the shallow foundation was placed; hence the excessive total and differential settlements.

scholarly journals Regional Geotechnical Mapping Employing Kriging on Electronic Geodatabase

2020 ◽  
Vol 10 (21) ◽  
pp. 7625
Author(s):  
Muhammad Usman Arshid ◽  
M. A. Kamal
Keyword(s):  
Bearing Capacity ◽  
Soil Classification ◽  
Geostatistical Analysis ◽  
Kriging Interpolation ◽  
Geospatial Information ◽  
State Highway ◽  
Capacity Evaluation ◽  
Geotechnical Investigations ◽  
Allowable Bearing Capacity ◽  
Spatial Analyst

A regional geotechnical map was developed by employing kriging using spatial and s geostatistical analysis tools. Many studies have been carried out in the field of topography, digital elevation modeling, agriculture, geological, crop, and precipitation mapping. However, no significant contribution to the development of geotechnical mapping has been made. For the appraisal of a geotechnical map, extensive field explorations were carried out throughout the geotechnically diversified plateau spread over an area of approximately 23,000 km2. In total, 450 soil samples were collected from 75 data stations to determine requisite index properties and soil classification for the subsequent allowable bearing capacity evaluation. The formatted test results, along with associated geospatial information, were uploaded to ArcMap, which created an initial input electronic database. The kriging technique of geostatistical analysis was determined to be more feasible for generating a geotechnical map. The developed map represents the distribution of soil in the region as per the engineering classification system, allowable bearing capacity, and American Association of State Highway and Transportation Officials (AASHTO) subgrade rating for 1.5-, 3.0-, and 4.5-m depths. The accuracy of the maps generated using kriging interpolation technique under spatial analyst tools was verified by comparing the values in the generated surface with the actual values measured at randomly selected validation points. The database was primarily created for the appraisal of geotechnical maps and can also be used for preliminary geotechnical investigations, which saves the cost of soil investigations. In addition, this approach allows establishing useful correlations among the geotechnical properties of soil.

Nomographs for predicting allowable bearing capacity and elastic settlement of shallow foundation on granular soil

2019 ◽  
Vol 12 (15) ◽  
Author(s):  
Maher Omar ◽  
Abdallah Shanableh ◽  
Khaled Hamad ◽  
Ali Tahmaz ◽  
Mohamed G. Arab ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Shallow Foundation ◽  
Granular Soil ◽  
Allowable Bearing Capacity ◽  
Elastic Settlement

scholarly journals INVESTIGATION OF SHALLOW FOUNDATION SOIL BEARING CAPACITY AND SETTLEMENT CHARACTERISTICS OF MINNA CITY CENTRE DEVELOPMENT SITE USING PLAXIS 2D SOFTWARE AND EMPIRICAL FORMULATIONS

2017 ◽  
Vol 36 (3) ◽  
pp. 663-670
Author(s):  
AB Salahudeen ◽  
JA Sadeeq
Keyword(s):  
Soil Properties ◽  
Bearing Capacity ◽  
Average Energy ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Analytical Models ◽  
City Centre ◽  
Foundation Soil ◽  
Development Site ◽  
Allowable Bearing Pressure

This study investigated the soil bearing capacity and foundation settlement characteristics of Minna City Centre development site using standard penetration test (SPT) data obtained from10 SPT boreholes at 0.6, 2.1 and 3.6 m depths to correlate soil properties. Evaluation of foundation bearing capacity and settlement characteristics for geotechnical preliminary design of foundations was carried out using some conventional empirical/analytical models and numerical modelling. The aim was to investigate and determine the geotechnical parameters required for adequate design of Physical structures of the proposed Minna City Centre, at Minna the capital of Niger state. The SPT N-values were corrected to the standard average energy of 60% (N60) before the soil properties were evaluated. Using the corrected N-values, allowable bearing pressure and elastic settlement of shallow foundations were predicted at 50 kN/m2 applied foundation pressure. The numerical analysis results using Plaxis 2D, a finite element code, shows the analytical/empirical methods of estimating the allowable bearing pressure and settlements of shallow foundations that provided acceptable results. Results obtained show that an average bearing capacity value of 100 – 250 kN/m2 can be used for shallow foundations with embedment of 0.6 to 3.6 m on the site.  http://dx.doi.org/10.4314/njt.v36i3.1

scholarly journals Computation of bearing capacity in a multi-layered soil unit: A case study from Dharan, Eastern Nepal

2004 ◽  
Vol 29 ◽  
Author(s):  
Tara Nidhi Bhattarai
Keyword(s):  
Bearing Capacity ◽  
Shear Failure ◽  
Standard Penetration Test ◽  
Layered Soil ◽  
Layer System ◽  
Foundation Soil ◽  
Geological Conditions ◽  
Geotechnical Investigations ◽  
Soil Unit

In this paper, a process of input data preparation for bearing capacity analysis in a multi-layered soil unit is presented. The method first takes into account of the engineering geological conditions of the construction site followed by geotechnical investigations that includes, among others, drilling boreholes at particulars sites also performing standard penetration test (SPT). Besides, various laboratory tests, including consolidation test, were also performed on soil samples collected from different soil layers. Finally, the soil is generalized into certain layer system and the bearing capacity of the foundation soil is computed using both shear failure as well as settlement criteria.

scholarly journals Daya Dukung Tanah Fondasi Dangkal Pada Bukit Hambalang Bagian Selatan, Kecamatan Citeureup, Kabupaten Bogor

2017 ◽  
Vol 8 (3) ◽  
pp. 143
Author(s):  
Rifki Asrul Sani
Keyword(s):  
Bearing Capacity ◽  
Standard Penetration Test ◽  
Geological Mapping ◽  
Shallow Foundation ◽  
Soil Parameters ◽  
Penetration Test ◽  
Square Footing ◽  
Local Soil ◽  
Allowable Bearing Capacity ◽  
Shear Condition

ABSTRAKSeiring dengan terjadinya longsoran di beberapa titik wilayah di bukit Hambalang, maka diperlukan kajian data kondisi geologi teknik berupa sifat fisik dan mekanik tanah serta batuan bawah permukaan, terutama mengenai daya dukung tanah dalam menahan beban bangunan di atasnya agar tidak terjadi penurunan. Metode yang digunakan dalam penelitian ini dibagi menjadi tiga, yaitu metode penelitian studio dengan memanfaatkan data-data sekunder yang telah ada, metode penelitian di lapangan melalui pemetaan geologi untuk mendapatkan data litologi yang tersingkap di permukaan, zonasi longsoran yang terjadi, dan identifikasi kekuatan tanah hasil pemboran geoteknik dengan Standard Penetration Test (SPT), serta metode penelitian di laboratorium untuk mendapatkan parameter sifat fisik dan mekanik tanah sebagai penunjang data daya dukung tanah serta geologi teknik daerah penelitian. Hasil perhitungan fondasi dangkal untuk general soil shear condition dan local soil shear condition dapat disimpulkan bahwa daya dukung tanah yang diizinkan (qa) untuk setiap kedalaman yang paling tinggi pada fondasi bujur sangkar (square footing) dan nilai tertinggi yang terdapat pada kedalaman 2 m, yaitu 57,32 ton/m2 dan 36,11 ton/m2. Fondasi yang paling rendah untuk semua kedalaman pada fondasi menerus (continuous footing) untuk kedalaman 2 m memiliki nilai 34,49 ton/m2 dan 21,25 ton/m2. Berdasarkan data SPT, nilai daya dukung yang diizinkan (qa) pada masing-masing titik bor berkisar pada rentang 2,85 ton/m2 sampai 16,85 ton/m2. Kata kunci: longsoran, daya dukung, Standard Penetration Test (SPT). ABSTRACTAlong with the landslide in some areas on the Hambalang Hill, it needs data of engineering geological study such as mechanical and physical properties of soil also subsurface rocks. Especially regarding the soil bearing capacity in order to restrain the building from settlement. There are three methods which used in this research, those are studio research by using secondary data, fieldwork research that is geological mapping conducted to obtain data on lithological rocks at surface, landslide zone and soil strength identification from geotechnical drilling with Standard Penetration Test (SPT) and laboratory research to obtain the soil parameters of physical and mechanical properties, which used to support soil bearing capacity data and engineering geology in research area. The calculation results of the shallow foundation for general soil shear condition and the local soil shear condition it could be concluded that the allowable bearing capacity for all depth which is highest at the square footing and the highest value found to a depth of 2 m, that is 57.32 ton/m2 and 36.11 ton/m2. The lowest foundation for all the depth of the continuous footing to a depth of 2 m had value 34.49 ton/m2 and 21.25 ton/m2. Based on data from SPT, the allowable bearing capacity on each of borehole ranging from 2.85 ton/m2 to 16.85 ton/m2. Keywords: landslide, bearing capacity, Standard Penetration Test (SPT).

scholarly journals A Framework to Predict the Load-Settlement Behavior of Shallow Foundations in a Range of Soils from Silty Clays to Sands using CPT Records

2021 ◽  
Author(s):  
Hossein MolaAbasi ◽  
Aghileh Khajeh ◽  
REZA JAMSHIDI CHENARI ◽  
Meghdad Payan
Keyword(s):  
Bearing Capacity ◽  
Volterra Series ◽  
Current Model ◽  
Shallow Foundations ◽  
Hyperbolic Function ◽  
Cone Penetration ◽  
Settlement Behavior ◽  
Tip Resistance ◽  
Allowable Bearing Capacity ◽  
Load Tests

Abstract Using a set of cone penetration test (CPT) records,the current paper develops a general framework based on regression analyses to model the load-settlement (q-s) behavior of shallow foundations resting on a variety of soils ranging from silty clays to sands.A three-parameter hyperbolic function is employed to rigorously examine the obtainedq-s curves, and to determine the model parameters.Also, the results of someCPT soundings, including the corrected cone tip resistance (qt) and the skin friction (Rf),are adopted to predict the results of plate load tests(PLT). The findingscorroborate the high accuracy of the proposed model, thereasonable performance of the hyperbolic function and the use of the Volterra series to predict the q-s curves.Moreover, the obtained curves from the newly developed model arecompared to those from other methods in the literature which cross-confirms the efficacyof the current model. Asensitivity analysis isalso conductedand the exclusive effects of all the contributing parameters are assessed among which Rfis shown to be the most influential. Ultimately, simple solutionsare adoptedto determine variouskey geotechnical parameters, like the ultimate bearing capacity (qult), the allowable bearing capacity (qa) andthe modulus of subgrade reaction (ks).

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