scholarly journals STRENGTH CHARACTERIZATION OF FOUNDATION SOILS AT FEDERAL UNIVERSITY LOKOJA BASED ON STANDARD PENETRATION TESTS DATA

2017 ◽  
Vol 36 (3) ◽  
pp. 671-676
Author(s):  
JA Sadeeq ◽  
AB Salahudeen
Keyword(s):  
Soil Properties ◽  
Estimation Method ◽  
Average Energy ◽  
Standard Penetration Test ◽  
Analytical Models ◽  
Penetration Test ◽  
Strength Characterization ◽  
Penetration Tests ◽  
Allowable Bearing Pressure

Strength characteristics of foundation soils in the Permanent site of the Federal University Lokoja in Kogi State were evaluated based on standard penetration test (SPT) results using some conventional analytical models proposed by different researchers. The study was carried out in order to take precise engineering decisions on the type of foundations suitable for the proposed structures and to determine the optimal depth of foundation embedment.  The SPT N-values were first corrected to the standard average energy of 60% (N60) before they were used to correlate soil properties. Evaluation of the soil properties were done at foundation embedment depths of 0.6, 2.1 and 3.6 m. Results show that bearing capacity generally increased with boring depth. Based on the Meyerhof allowable bearing pressure estimation method, foundation pressures in the range of 150 – 600  kN/m2 were evaluated for use in the study area at shallow depths (depths in the range of 0.6 - 3.6 m).http://dx.doi.org/10.4314/njt.v36i3.2

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 GEOTECHNICAL PROPERTIES AND STRENGTH CHARACTERIZATION OF NIGERIAN SOILS

2019 ◽  
pp. 85-96
Keyword(s):  
Soil Properties ◽  
Bearing Capacity ◽  
Average Energy ◽  
Standard Penetration Test ◽  
Internal Resistance ◽  
Strength Characteristics ◽  
Analytical Models ◽  
North West ◽  
North East ◽  
Nigerian Soils

Strength characteristics of foundation soils in the six geo-political zones of Nigeria were evaluated based on standard penetration test (SPT) results using some conventional empirical/analytical models and the bearing capacity was predicted by numerical analysis using Plaxis 3D, a finite element application package. The SPT N-values were first corrected to the standard average energy of 60% (N60) before they were used to correlate soil properties. Evaluation of the soil properties were done at foundation embedment depths of 0.6, 2.1, 3.6, 5.1, 6.6, 8.1, 9.6, 11.1 and 12.6 m. The results of overconsolidation ratio, rigidity index, relative density, angle of internal resistance, undrained shear strength and unconfined compressive strength show that the strength characteristics of Nigerian soils is lowest on the average in the South South (SS) geo-political zone, followed by South West (SW), South East (SE), North East (NE), North West (NW) and the North Central (NC) geo-political zone has the highest prediction of strength characteristics. Bearing capacity generally increased with boring depth and having its lowest values in the SS geo-political zone and increased for the remaining zones in the order of SW, SE, NE, NW and the NC geopolitical zone.

scholarly journals Effect of Micropiles on Clean Sand Liquefaction Risk Based on CPT and SPT

2020 ◽  
Vol 10 (9) ◽  
pp. 3111 ◽  
Author(s):  
Visar Farhangi ◽  
Moses Karakouzian ◽  
Marten Geertsema
Keyword(s):  
Soil Properties ◽  
Factor Of Safety ◽  
Standard Penetration Test ◽  
Strength Properties ◽  
Soil Liquefaction ◽  
Penetration Test ◽  
Sand Liquefaction ◽  
Abrupt Decrease ◽  
Novel Approach ◽  
Jet Grouting

Liquefaction is a hazardous seismic-based phenomenon, which causes an abrupt decrease in soil strength properties and can result in the massive destruction of the built environment. This research presents a novel approach to reduce the risk of soil liquefaction using jet-grouted micropiles in clean sands. The saturated soil profile of the study project mainly contains clean sands, which are suitable to more reliably employ simplified soil liquefaction analyses. The grouting is conducted using 420 micropiles to increase the existing soil properties. The effect of jet grouting on reducing the potential of liquefaction is assessed using the results of the cone penetration test (CPT) and the standard penetration test (SPT), which were conducted before and after jet grouting by implementing micropiles in the project sites. According to three CPT-based liquefaction analyses, the Juang method predicts the most effective improvement range of the factor of safety in the clean sand. The Boulanger and Idriss, and Eurocode methods show comparable evaluations. Results of the SPT-based analyses show the most considerable increase of the factor of safety following the Boulanger and Idriss, and NCEER approaches in the SP soil. CPT- and SPT-based analyses confirm the effectiveness of jet grouting by micropiles on enhancing soil properties and reducing the risk of liquefaction.

A method for correlating large penetration test (LPT) to standard penetration test (SPT) blow counts

2003 ◽  
Vol 40 (1) ◽  
pp. 66-77 ◽  
Author(s):  
Chris R Daniel ◽  
John A Howie ◽  
Alex Sy
Keyword(s):  
Wave Equation ◽  
Correlation Method ◽  
Standard Penetration Test ◽  
Penetration Test ◽  
Unified Approach ◽  
Equation Analysis ◽  
Gravelly Soils ◽  
Penetration Tests ◽  
Correlation Factors ◽  
Good Agreement

The standard penetration test (SPT) split-spoon sampler is too small for investigations in gravelly soils. For this reason, several researchers have developed scaled-up versions of the SPT, commonly referred to as "large penetration tests" (LPT), and attempted to correlate the measured blow counts to SPT blow counts. Several LPTs have been in use worldwide; each with different drill rods, sampler dimensions, and hammer energies; hence existing published LPT–SPT correlations differ for each system. This paper summarizes the LPT data in the literature and presents a fundamental method for predicting LPT–SPT correlations. The proposed method is based on wave equation analyses of SPT and LPT and considers variations in test equipment, penetration resistance, and energy. It is shown that the method provides a unified approach for assimilating the various published LPT–SPT correlations. Additional SPT and LPT data were collected at a sand research site to check the proposed method and to expand the LPT database. The observed and predicted correlation factors are shown to be in good agreement. The proposed correlation method will be useful as a logical framework for the comparison of LPT data collected throughout the world. Additional research will be required to extend this procedure to gravel sites.Key words: large penetration test, LPT, fundamental correlation method, wave equation analysis, grain size effects.

scholarly journals Cramming the Specificities in Contemplating Safe Bearing Capacity for the Foundation Assessed from Borehole Samples in a Sandy-Moorum Zone

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tarun Kumar Lohani ◽  
Melkamu Teshome Ayana ◽  
Abdella Kemal Mohammed ◽  
Jyotiranjan Pattanaik
Keyword(s):  
Soil Properties ◽  
Bearing Capacity ◽  
Laboratory Testing ◽  
Standard Penetration Test ◽  
Soil Samples ◽  
Clear Understanding ◽  
Foundation Settlement ◽  
Penetration Test ◽  
Spt Data ◽  
Allowable Settlement

Borehole samples drilled up to a depth of 10 m provide a clear understanding whether a foundation is safe for any structure. The main objective of the present study reconnoitered the soil bearing capacity and foundation settlement characteristics using the standard penetration test (SPT) data obtained from 3 boreholes at 1 m, 2 m, and 3 m depths to correlate soil properties and deterrents, if any, created by groundwater. The methodology of the research is to collect soil samples, and ensuing subsoil analysis was performed in order to obtain concrete information to optimize the foundation system within the safe bearing capacity of soil and its allowable settlement. The scope of the work encompasses conducting detailed soil investigation from drilling logs, laboratory testing, and conducting and estimating safe bearing capacity. The result of the research aims at providing safety to the foundation from the investigations of conclusive recommendation to be adopted which would be economically feasible and structurally secured.

Modified Standard Penetration Test for Drilled Shaft Design in Weak Fine-Grained Rocks

2021 ◽  
pp. 036119812110378
Author(s):  
Timothy D. Stark ◽  
Ahmed K. Baghdady ◽  
Abdolreza Osouli ◽  
Heather Shoup ◽  
Michael A. Short
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Penetration Rate ◽  
Standard Penetration Test ◽  
Drilled Shafts ◽  
Penetration Test ◽  
Weak Rocks ◽  
Fine Grained ◽  
Linear Slope ◽  
Penetration Tests

Standard penetration tests (SPTs) have been used to estimate strength parameters of soils and weak rocks when it is difficult to obtain high-quality samples for laboratory shear testing. SPTs require 45 cm (18 in.) of split-spoon sampler penetration to determine the blowcounts per 0.3 m (1 ft), which is difficult to impossible to obtain in weak rock, that is, intermediate geomaterials. As a result, a modified SPT is presented here for sampler penetrations less than 45 cm (18 in.) in weak rocks. This new procedure is termed the modified standard penetration test (MSPT) and uses the penetration rate, not the sum of penetration blowcounts per 0.3 m, to estimate the unconfined compressive strength for the design of drilled shafts in weak fine-grained rocks. The penetration rate is the inverse of the linear slope of the penetration depth versus blowcount relationship. With this new test and interpretation procedure, 45 cm (18 in.) of sampler penetration is no longer required to estimate the unconfined compressive strength of weak rocks. An empirical correlation between MSPT penetration rate and laboratory-measured unconfined compressive strength is presented here for weak Illinois shale. This correlation could be used to estimate the unconfined compressive strength for the design of drilled shafts in weak rocks.

In Situ Investigation of Liquefiable Gravels

2000 ◽  
Vol 1714 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Joseph P. Koester ◽  
Chris Daniel ◽  
Michael L. Anderson
Keyword(s):  
Standard Penetration Test ◽  
Lateral Spreading ◽  
Test Results ◽  
Penetration Test ◽  
Liquefaction Resistance ◽  
Testing Procedures ◽  
In Situ Investigation ◽  
Penetration Tests

A series of dynamic in situ penetration tests was performed in deep alluvial gravel deposits at Seward, Alaska, that were shaken and apparently liquefied by the March 27, 1964, Alaska earthquake. Both a U.S. standard penetration test split spoon and a larger-diameter drive sampler were used, and dynamic cone penetrometers of two sizes were also driven into the gravels near the mouth of the Resurrection River that had exhibited settlement and lateral spreading as a result of earthquake shaking. Two safety hammers were used [nominally 623 N (140 lb) and 1334 N (300 lb)], and the energy delivered with various hammer and penetrometer combinations was measured throughout all tests. Limited measurements of hammer velocity were also made by a radar system developed for that purpose to allow for kinetic energy determination. Soils recovered in the split spoon samplers were sent to the U.S. Army Engineer Waterways Experiment Station Soils Research Facility in Vicksburg, Mississippi, where they were evaluated for classification (gradation and index properties). The sampling and testing procedures used at the Seward site, as well as preliminary analysis of the various penetration test results, are summarized. Comparisons are made with penetration resistance measurements made by the Alaska Highway Department immediately after the 1964 earthquake. Results of this investigation will be adapted to guide future practice for in situ determination of liquefaction resistance in coarse alluvial soils.

scholarly journals Selection of Standard Penetration Test Number for Geotechnical Investigation of a Vertical Cross-section Considering Spatial Variability and Correlation in Soil Properties

2021 ◽  
Author(s):  
Zheng Guan ◽  
Yu Wang
Keyword(s):  
Spatial Variability ◽  
Soil Properties ◽  
Cross Section ◽  
Site Investigation ◽  
Standard Penetration Test ◽  
Vertical Cross Section ◽  
Penetration Test ◽  
Geotechnical Design ◽  
Selection Of

Standard Penetration test (SPT) is a widely used in-situ test for characterizing variation of subsurface soil properties, and results of site investigation are usually simplified as a 2D vertical cross-section for subsequent geotechnical design and construction. Current geotechnical design codes and guidelines only provide general recommendations for selection of an appropriate number of in-situ tests (e.g., SPT) (e.g., the greater variability of subsurface conditions, the larger number of SPTs required to obtain sufficient underground information). No quantitative or rational method is available for selecting the appropriate number of SPTs considering spatial variability and correlation in subsurface conditions. A comprehensive parametric study is carried out in this study to investigate the influence of spatial variability in subsurface conditions on the minimum SPT number needed for satisfying an accuracy requirement of site investigation. Random field is adopted to model spatial variation and correlation in soil properties in typical site conditions, and 2D Bayesian compressive sampling is used to interpolate sparse SPT data. Based on the parametric study results, a statistical chart is developed for geotechnical engineers to conveniently select appropriate number of SPTs in a vertical cross-section. Real SPT data from New Zealand are used to illustrate and validate the proposed method.

Static cone tests and settlement of calcareous desert sands

1986 ◽  
Vol 23 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Nabil F. Ismael ◽  
Abdul Majeed Jeragh
Keyword(s):  
Ground Surface ◽  
Field Tests ◽  
Standard Penetration Test ◽  
Penetration Test ◽  
Cone Penetration ◽  
Soil Pressure ◽  
Cone Penetration Tests ◽  
Below Ground ◽  
Load Tests ◽  
Penetration Tests

The results of a recent in situ testing program to establish standard penetration test – cone penetration test (SPT–CPT) correlation for the windblown calcareous desert sands of Kuwait are presented and analyzed. The program consisted of auger borings and static cone tests at five sites along a 35 km long corridor. The resulting correlation was employed for prediction of the allowable soil pressure of footings at seven sites in Kuwait where load tests were carried out on square concrete footings placed at a depth of 1 m below ground surface. A comparison of the measured to the predicted soil pressures using the Schmertmann method indicated very close agreement. The average ratio of measured to predicted soil pressure is 93% for the seven test sites. Recommendations are made for further testing to determine the long-term settlement components due to creep and cyclic loading. Key words: load tests, sands, footings, allowable pressure, settlement, field tests, borings, cone penetration tests.

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