scholarly journals Geotechnical Site Investigation for Proposed Minna City Centre Development in Niger State

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Ja'afar A Sadeeq ◽  
Anigilaje B Salahudeen
Keyword(s):  
Bearing Capacity ◽  
Site Investigation ◽  
City Centre ◽  
Embedment Depth ◽  
Particle Sizes ◽  
Geotechnical Parameters ◽  
Angle Of Internal Friction ◽  
Shearing Resistance ◽  
Allowable Bearing Capacity ◽  
Adequate Design

This study was carried out to investigate and determine the geotechnical parameters required for adequate design and positioning of structures and facilities of the proposed Minna City Centre, at Minna the capital of Niger state. The soil samples used for the study were obtained from 10 SPT boreholes at 0.6, 2.1 and 3.6 m depths and all laboratory tests were conducted in accordance with BS 1377. Results show that soil particle sizes increases with boring depth up to the basement complex and values of cohesion and angle of internal friction show that the shearing resistance and bearing capacity of soils will be relatively high and favourable for the intended structures. Average allowable bearing capacity values in the range of 100 – 300 kN/m2 are recommended for use in the study area with embedment depth between 1 – 3 m.

scholarly journals Correlation between Electrical Resistivity and Cone Penetrometer Test Data for Geotechnical Site Investigation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
I. A. Akinlabi
Keyword(s):  
Electrical Resistivity ◽  
Bearing Capacity ◽  
Test Data ◽  
Empirical Relation ◽  
Site Investigation ◽  
Cone Penetrometer ◽  
Soil Resistivity ◽  
Empirical Relationships ◽  
Cone Resistance ◽  
Allowable Bearing Capacity

The use of the electrical resistivity method provides cost-effective subsurface information faster and allows reliable interpolation to be made between the tested points. It is therefore desirable to generate consistent data from resistivity measurements by using empirical relationships while only few zones of interest will require testing. This study, therefore, developed empirical relationships between electrical resistivity sounding and cone penetrometer test data for engineering site investigation using a case study from the Basement Complex Terrain of Southwestern Nigeria. Regression analysis was used to assess the correlation between the soil resistivity and cone resistance and the validity of the empirical relation was evaluated by comparing values estimated from the soil resistivity vs. cone resistance cross plot with field values obtained from cone penetration tests. The values of allowable bearing pressure computed by using both values in Meyerhof’s equation were also compared with the allowable bearing capacity deduced with laboratory values of soil strength parameters (cohesion, angle of internal friction, soil unit weight) in Terzaghi’s general formula. The results show close agreement between the measured and estimated values with the differences typically less than 10%. The standard errors of the estimates for the cone resistance and allowable bearing capacity are 2.70 and 4.16 respectively, implying reliability of the estimates. The proposed empirical relationships, therefore, appear to provide reasonable estimation of soil cone resistance and allowable bearing capacity from soil resistivity. Few complimentary cone penetrometer and laboratory tests will thus be required while the cost and duration of site investigation for engineering structures are expected to reduce.

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.

Development of allowable bearing capacity for strip foundations in unsaturated soils

2019 ◽  
Vol 114 ◽  
pp. 103138 ◽  
Author(s):  
Changguang Zhang ◽  
Benxian Gao ◽  
Qing Yan ◽  
Junhai Zhao ◽  
Lizhou Wu
Keyword(s):  
Bearing Capacity ◽  
Unsaturated Soils ◽  
Allowable Bearing Capacity

scholarly journals Analysis of displacement of excavation based on inclinometer measurements

2012 ◽  
Vol 34 (4) ◽  
pp. 3-16 ◽  
Author(s):  
Karolina Gorska ◽  
Marek Wyjadłowski
Keyword(s):  
Theoretical Calculations ◽  
Back Analysis ◽  
Field Measurements ◽  
Soil Medium ◽  
Geotechnical Parameters ◽  
Angle Of Internal Friction ◽  
Material Parameters ◽  
Bored Pile ◽  
Excavation Process ◽  
Excavation Support

Abstract The article presents back analysis to estimate geotechnical parameters of fill layer. The agreement between field measurements and theoretical calculations was examined. Displacements of a cantilever CFA bored pile wall were monitored. The inclinometric measurements were taken directly after pile construction and according to excavation process. Over 200 calculation series were performed, with changing fill parameters. The calculations employed the actual geometric and material parameters of the pile wall, as well as geotechnical parameters of layered soil. The parameters estimated through back analysis were the angle of internal friction and Young’s modulus of fill layer. In the case discussed, pile wall cap displacement was the response of the system, and soil medium parameters were the input data. The agreement between theoretical calculations and inclinometer measurements was assessed in accordance with two functions. The measured horizontal displacements of excavation support structure assumed different values at the two inclinometer sites analysed. Back analysis results for these sites are approximately convergent for a final excavation depth.

Mapping faults in an urban environment from borehole data (Oviedo, NW Spain)

2021 ◽  
Author(s):  
Luis Pando ◽  
Carlos López-Fernández ◽  
Germán Flor-Blanco ◽  
Sergio Llana-Fúnez
Keyword(s):  
Site Investigation ◽  
Geological Mapping ◽  
City Centre ◽  
Nw Spain ◽  
Regional Literature ◽  
Borehole Data ◽  
Urban Core ◽  
Structural Relationships ◽  
Geotechnical Database ◽  
Lithostratigraphic Units

<p>The detailed geological mapping in built-up areas presents challenges that arise mainly from the covering of outcrops, and the erase of natural geomorphological features during earthmoving works related to urban development. However, it also benefits from the existence of closely spaced site investigation data, including boreholes, not commonly available outside the cities.</p><p>This contribution explains the procedure carried out to improve the interpretation of faults below the city centre of an urban core located in NW Spain. Oviedo is placed on a basin formed by an alternation of sub-horizontal carbonate and siliciclastic formations of Cretaceous age, over which lies an unconformable cover of Paleogene fluvial-lacustrine deposits mostly composed by clays and marls. The paleorelief over which the Paleogene was deposited results in great lateral changes in the thickness of these sediments. Moreover, the basin was deformed during the Alpine convergence in northern Iberia developing an open syncline oriented East-West. During the shortening, a number of minor faults cutting across the gently dipping Cretaceous and Paleogene deposits affect moderately the cartographic pattern of lithostratigraphic units.</p><p>Therefore, this research was focused on the preferential use of information on the ground provided by hundreds of rotary boreholes managed through a GIS-type geotechnical database. The procedure of semiautomatic identification consisted essentially of investigating the spatial variations of the boundary between two Cretaceous formations, in order to find anomalies attributable to fault displacements. In using this boundary as a strain marker for post-depositional deformation, two scales were approached, one aimed at the identification of large faults, and another with greater detail based on trend-surface analysis for fractures of smaller size and local incidence (vertical offset less than 10 m).</p><p>The research has allowed to discuss faults deduced in previous geological maps, helping to interpret thickenings related to the paleorelief, and also to recognize the existence of structures not described in the regional literature. This study provides also better constrains to the analysis of the structural relationships between the faults affecting the Mesozoic-Palaeogene basin, and the Alpine reactivation of the underlying Palaeozoic basement.</p>

scholarly journals Improvement ratio and behavior of bearing capacity factors for strip skirt footing model resting on sand of different grain size distribution

2018 ◽  
Vol 162 ◽  
pp. 01026
Author(s):  
Mahmood Rashid Mahmood
Keyword(s):  
Grain Size ◽  
Bearing Capacity ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Coarse Sand ◽  
Linear Increase ◽  
Angle Of Internal Friction ◽  
Theoretical Approaches ◽  
Different Grain Size ◽  
Improvement Ratio

Plain strain model tests were performed on beds of sands with different particle size distribution (Coarse, Medium and Fine) prepared at loose state (Relative density Dr. of 30%). A strip footing model with skirt was placed on the bed of sand and loaded vertically up to failure at different ratios of skirt depth to width D/B of (0.5, 1.0, 1.5, 2, and 3). The applied stress increments and the corresponding settlements were measured. The improvement ratio due to different skirt depth and the behavior of bearing capacity parameters Nγ and Nq at each depth were evaluated and compared with some theoretical approaches. The test results revealed that the improvement ratio increased linearly up to D/B of 1.5 then reduced. Two factors were introduce into the general bearing capacity equation where used to evaluate bearing capacity of skirt footing, there values are about 1.6 for skirt ratio ranged between 0.5 to 1.5, and 1.25 for skirt ratio more than 1.5. Also, it is found that the Nγ parameter for D/B=0 were very close to Vesic proposal for fine and medium grain size distribution, while it’s close to Biarez proposal for coarse sand. The behavior of Nq parameter with different skirt ratio shows slight increase up to D/B of 1.5 then decrease with increasing D/B ratio for different grain size distribution. While the behavior of theoretical Nq parameter (depending on angle of internal friction values) shows a linear increase with skirt ratio for different grain size distribution.

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.

Sign in / Sign up

Export Citation Format

Share Document