Determination of Geotechnical Properties of Clayey Soil from Resistivity Imaging (RI)

Determination of Geotechnical Properties of Clayey Soil from Resistivity Imaging (RI)
Author: Golam Kibria
Publisher:
Total Pages:
Release: 2011
Genre:
ISBN:

The use of resistivity imaging (RI) in the subsurface investigation has increased in recent years. RI is a non destructive method and provides a continuous image of the subsurface. Based on the electrical conduction phenomenon of soil, spatial and temporal moisture variation and heterogeneity of subsurface can be evaluated from RI. However, only qualitative evaluation of subsurface can be obtained from RI. The correlation between RI results and geotechnical engineering properties of soils has become an important issue for rigorous use of this method in site investigation. The current study attempts to develop the relationship and correlations between geotechnical parameters with electrical resistivity of soil. These correlations can be used for determining geotechnical properties from RI. Soil samples collected for the current study mostly consisted of medium to high plasticity clay with plasticity index more than 30. High energy X-Ray fluorescence (XRF) and scanning electron microscope (SEM) image analysis showed that the dominant clay mineral in the soil samples might be montmorillonite. The effects of moisture content, unit weight, degree of saturation, specific surface area, pore space, ion composition, compaction condition and fine fraction on soil resistivity were determined. Test results showed that soil resistivity decreased with the average rate of 13.8 Ohm-m for the increase of moisture from 10% to 20% at fixed unit weight. However, soil resistivity ranged from 2.1 to 2.42 ohm-m at 50% moisture content. Enhanced interaction between the clay particles and water and occurrence of ionic conduction reduced electrical resistivity with the increase of moisture content. Test results also indicated that soil resistivity decreased almost linearly with an average rate of 0.3 Ohm-m/pcf between moist unit weight 88.5 to 100 pcf at 18% moisture content. The average rate of reduction was 0.08 Ohm-m/pcf for further increase in moist unit weight in same moisture content. Reduction of interclod pores and better particle-to-particle contact might cause reduction in soil resistivity with the increase of unit weight. However, soil resistivity was more sensitive to moisture content than unit weight. In addition, average resistivity of the samples decreased from 6.7 to 3.2 Ohm-m with the increase of degree of saturation from 40% to 90% due to elimination of interclod macro pores, reorientation of clay particle and remolding of clay. Soil resistivity increased from 4.3 to 14.2 Ohm-m with the increase of specific surface area from 69.6 to 107.1 m2/gm at 18% moisture content and 75 pcf dry unit weight. Lack of formation of water film around the soil particle might restrict the current flow. Moreover, soil resistivity increased from 4.4 to 14.2 Ohm-m for the increase of pore space from 1.91% to 10.56% at 18% moisture content and 75 pcf dry unit weight and then decreased. Test results showed that soil resistivity increased from 4.3 to 14.2 Ohm-m with the increase of calcium ion from 8.3% to 13.9% at 18% moisture content and 75 pcf dry unit weight. Observed soil resistivity was high when samples were compacted at dry of optimum because of less pronounce bridging between soil particles. However, soil resistivity decreased when samples were compacted at wet of optimum. Near saturated voids and better interparticle bridging might caused the reduction in resistivity. Correlation of resistivity with unconfined shear strength of soil showed that soil samples prepared with moisture content below optimum, resistivity was high and strength was low. However, both resistivity and strength was low at moisture condition above optimum condition. In addition, soil resistivity were in between 3.16 to 3.6 Ohm-m for the increase of fine fraction from 66% to 94.8%. Therefore, the observed variation in soil resistivity with the fine content was not significant. Based on the study, it can be summarized that geotechnical engineering properties can be determined from RI under certain site specific conditions and moisture is the most influencing factor in electrical conduction.

Evaluation of Pysicho-mechanical Properties of Clayey Soils Using Electrical Resistivity Imaging Technique

Evaluation of Pysicho-mechanical Properties of Clayey Soils Using Electrical Resistivity Imaging Technique
Author: Golam Kibria
Publisher:
Total Pages: 318
Release: 2014
Genre: Clay soils
ISBN:

Resistivity imaging (RI) is a promising approach to obtaining continuous profile of soil subsurface. This method offers simple technique to identify moisture variation and heterogeneity of the investigated area. However, at present, only qualitative information of subsurface can be obtained using RI. A study on the quantification of geotechnical properties has become important for rigorous use of this method in the evaluation of geohazard potential and construction quality control of landfill liner system. Several studies have been performed to describe electrical resistivity of soil as a function of pore fluid conductivity and surface conductance. However, characterization tests on pore water and surface charge are not typically performed in a conventional geotechnical investigation. The overall objective of this study is to develop correlations between geotechnical parameters and electrical resistivity of soil, which would provide a mean to estimate geotechnical properties from RI. As a part of the study, multiple regression analyses were conducted to develop practically applicable models correlating resistivity with influential geotechnical parameters. The soil samples considered in this study were classified as highly plastic clay (CH) and low plasticity clay (CL) according to Unified Soil Classification System (USCS). Based on the physical tests, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) analysis, kaolinite was identified as the dominant mineral with some traces of magnesium, calcium, potassium, and iron. Electrical resistivity tests were conducted on compacted clays and undisturbed samples under varied geotechnical conditions. The experimental results indicated that the degree of saturation substantially influenced electrical resistivity. Electrical resistivity decreased as much as 11 times from initial value for the increase of degree of saturation from 23 to 100% in the laboratory tests on compacted clays. In case of undisturbed soil samples, resistivity decreased as much as sixteen fold (49.4 to 3.2 Ohm-m) for an increase of saturation from 31 to 100%. Furthermore, the resistivity results were different for the specimens at a specific degree of saturation because of varied surface activity and isomorphous substitution of clayey soils. In addition to physical properties, compressibility of clays was correlated with electrical conductivity. Based on the investigation, it was determined that the electrical conductivity vs. pressure curves followed similar trends as e vs. logp curves. Multiple linear regression (MLR) models were developed for compacted and undisturbed samples using statistical analysis software SAS (2009). During model development, degree of saturation and CEC were selected as independent variables. The proposed models were validated using experimental results on a different set of samples. Moreover, the applicability of the models in the determination of degrees of saturation was evaluated using field RI tests.

Site Investigation using Resistivity Imaging

Site Investigation using Resistivity Imaging
Author: Sahadat Hossain
Publisher: CRC Press
Total Pages: 232
Release: 2018-08-06
Genre: Science
ISBN: 1351047590

Subsurface investigation is the most important phase of any civil engineering construction or development activities. The geologic conditions can be extremely complex, variable, and subject to change with time; soil test borings and in-situ tests are employed to obtain subsoil information. Resistivity Imaging (RI) is a non-destructive, fast and cost-effective method of site investigation and soil characterization. Site Investigation using Resistivity Imaging aims to summarize pertinent details of RI in site investigation for geotechnical and geo-environmental applications. It aims to bridge the gap that currently exists between the geotechnical/geo-environmental and geophysical engineering community. The geotechnical and geo-environmental engineers will be able to use annd understand geophysical data and utilize the information for their design. Features: First comprehensive handbook aimed at engineers that summarises pertinent details of Resitivity Imaging (RI) in site investigation for geotechnical and geo-environmental applications. for geotechnical and geoenvironmental engineers, making it possible to interpret geophysical data and utilize the information for their design. explanining the advantages of RI over conventional site investigations: continuous image, large coverage, low cost, quick and easy data processing. It will be a comprehensive handbook for the application of RI in geotechnical and geo-environmental site investigations.

Evaluation of Geotechnical Parameters of Soil Using Electrical Resistivity Imaging

Evaluation of Geotechnical Parameters of Soil Using Electrical Resistivity Imaging
Author: Md Asif Akhtar
Publisher:
Total Pages: 218
Release: 2022
Genre: Engineering geology
ISBN:

Electric resistivity imaging (ERI) is an effective non-destructive and rapid measuring way of obtaining continuous soil subsurface resistivity profiles. An ERI technique can be used to identify moisture variations and soil heterogeneities in an area. Thus, ERI is becoming a popular tool in geotechnical (FHWA, 2015)engineering; however, it only provides qualitative information at the current time. Using qualitative images, it is challenging to extract quantitative geotechnical information, such as the type of soil, moisture content, degree of saturation, and atterberg limit, of the subsurface. Several studies have described the electrical resistance of soil as a function of pore fluid conductivity and surface conductance. Additionally, electrical resistivity measurements have also been made on commercial soils in order to determine the influence of geotechnical properties. Since a conventional geotechnical investigation may not perform characterization tests of porewater or surface charge, electrical resistivity must be correlated with geotechnical properties that can be tested in the laboratory. The objective of this experimental study is to investigate the relationship between the electrical properties of soil and geotechnical parameters of locally available soil and determine correlations between geotechnical parameters and electrical resistivity that can be used by geotechnical engineers. A study was conducted to study the electrical properties of soils obtained from 22 boreholesof four different locations, namely Fort-Worth, Beaumont, Corpus Christi, and El-Paso, selected based on their geological formation. Besides collecting soil samples through soil borings using the Texas Cone Penetration (TCP) method, a field, electrical resistivity survey was also conducted using 28 and 56 electrodes at the same locations to obtain a subsurface resistivity map. Field resistivity values were correlated with soil TCP values, and the correlation was compared to previous literature. In this study, 44 soil samples classified as low plastic clay (CL), 15 samples as high plastic clay (CH), and four samples as elastic silt (MH) were used to measure the resistivity of compacted clay soils. Furthermore, soil samples were categorized into six categories based on their liquid limit higher than 50, between 35 and 50, and lower than 35, and plastic limit higher than 25 and lower than 25 to investigate the changes in geoelectrical properties of soil. Various geotechnical conditions were used in laboratory tests to determine the influence of soil parameters on electrical resistivity. In both clayey soils and sandy soils, electrical resistivity measurements were found strongly influenced by the moisture content and degree of saturation. Soil resistivity was found to be averagely decreased by 80%, 43%, and 21% of initial value when the soil moisture content was increased from 10% to 20%, 20% to 30%, and 30% to 40% except for the soil samples contains liquid limit less than 50 and plasticity index higher than 25 for unit weight of 11.8 KN/m3.Soil resistivity was found to be decreased by 42%, 25%, and 41% for the above-mentioned water content due to the high activity of soil. Moreover, soil resistivity decreases 45% and 49% of the initial values when the unit weight increases from 11.8 KN/m3 to 13.4 KN/m3 and 13.4 KN/m3 to14.9 KN/m3. Soil resistivity decreases as much as 57-fold for normal clay and 7.5 fold for active clay from the initial value when the degree of saturation increased from 17% to 100%. However, the rate of change of resistivity is low when the degree of saturation of compacted clay is more than 50%. Furthermore, clay properties such as liquid limit and plasticity index also affect electrical resistance at different saturation levels. However, at a higher level of saturation, geotechnical parameters have less impact on electrical resistivity. The soil engineering properties of both sandy and clayey soils were correlated with electrical resistance using different multiple linear regression (MLR) models developed with R-studio. In developing a multiple linear regression equation for clayey soil, the degree of saturation and plasticity index were selected as independent parameters, while for sandy soil, moisture and sand content were used. Validation of the MLR models was based on field data, and therefore these models can be used for estimating engineering properties.

Proceedings of the 1st International Conference on Sustainable Waste Management through Design

Proceedings of the 1st International Conference on Sustainable Waste Management through Design
Author: Harvinder Singh
Publisher: Springer
Total Pages: 616
Release: 2018-10-30
Genre: Science
ISBN: 3030027074

This book describes the latest advances, innovations and applications in the field of waste management and environmental geomechanics as presented by leading researchers, engineers and practitioners at the International Conference on Sustainable Waste Management through Design (IC_SWMD), held in Ludhiana (Punjab), India on November 2-3, 2018. Providing a unique overview of new directions, and opportunities for sustainable and resilient design approaches to protect infrastructure and the environment, it discusses diverse topics related to civil engineering and construction aspects of the resource management cycle, from the minimization of waste, through the eco-friendly re-use and processing of waste materials, the management and disposal of residual wastes, to water treatments and technologies. It also encompasses strategies for reducing construction waste through better design, improved recovery, re-use, more efficient resource management and the performance of materials recovered from wastes. The contributions were selected by means of a rigorous peer-review process and highlight many exciting ideas that will spur novel research directions and foster multidisciplinary collaboration among different waste management specialists.

Measurement of Engineering Properties of Soils

Measurement of Engineering Properties of Soils
Author: E. S. Reddy
Publisher: New Age International
Total Pages: 244
Release: 2002
Genre: Engineering geology
ISBN: 9788122414134

This Book Highlights The Procedures For 30 Tests Used To Measure The Engineering Properties Of Soil In Both Laboratory And Field Including Dynamic Testing Of Soils. All The Test Procedures Are Based On Indian Standard Practice And Are Very Close To Astm Standards. Features Of This Book Include: * Test Procedures And Tabular Forms For A Maximum Number Of Field And Laboratory Tests. * Classification Of The Soil Tests Based On Type Of Project And Type Of Soil. * A Set Of Questions Is Presented At The End Of Each Chapter For Self Examination. * For Each Test, Theoretical Principles And The Precautions To Be Followed During The Test Are Explained.This Book Will Be Useful To B.Tech./B.E. (Civil Engineering) And M.E./ M.Tech. (Geotechnical Engineering) Students As Laboratory Manual And Reference Book. It Is Hoped That This Book Will Also Be Useful To Field Engineers As Handbook In Soil Mechanics As It Helps In Deciding The Test Programme For A Given Project. Similarly, The Book Will Be Helpful For Quality Control Engineers.

Proceedings of Indian Geotechnical and Geoenvironmental Engineering Conference (IGGEC) 2021, Vol. 1

Proceedings of Indian Geotechnical and Geoenvironmental Engineering Conference (IGGEC) 2021, Vol. 1
Author: Arvind Kumar Agnihotri
Publisher: Springer Nature
Total Pages: 594
Release: 2022-11-24
Genre: Science
ISBN: 9811947392

This book presents select proceedings of the Indian Geotechnical and Geoenvironmental Engineering Conference (IGGEC-21). Various topics covered in this book include geotechnical engineering, earthquake geotechnical engineering, geoenvironmental engineering, ground improvement, transportation geotechnics, waste management and sustainable engineering. The book will be a valuable reference for researchers and professionals in the discipline of civil, materials, geoenvironmental engineering, landfills, hydrogeology, ground improvement and earthquake geotechnical engineering.

Determination of Selected Geotechnical Properties of Soil Using Electrical Conductivity Testing

Determination of Selected Geotechnical Properties of Soil Using Electrical Conductivity Testing
Author: L. Sebastian Bryson
Publisher:
Total Pages: 10
Release: 2009
Genre: Clay fraction
ISBN:

The use of electrical conductivity measurements, at relatively low frequencies, has been shown to be an effective tool for characterizing soils for hydrogeological studies. Many of the properties that affect the hydraulic and mechanical behavior of a soil also affect the electrical response. Thus, there is a likelihood that electrical measurements of soils will provide useful information for predicting geotechnical parameters. This paper presents the results of efforts to develop an electrical conductivity testing system that can be used specifically to evaluate geotechnical properties of soils. The testing system consisted of a robust data acquisition and control system that allowed for autonomous testing of various sand-clay mixtures and a testing apparatus that was rugged enough to allow soil samples to be compacted directly into the cell. The testing apparatus utilized a multi-electrode configuration which facilitated the investigation of anisotropic electrical measurements of the compacted soil samples. The data obtained during the evaluation phase of this research showed that low-frequency electrical conductivity measurements are viable for evaluating and predicting geotechnical properties of soils such as void ratio and volumetric water content, and the use of the multi-electrode configuration is very promising for evaluating anisotropy in soils.

Civil Engineering And Urban Planning - Proceedings Of The 5th International Conference On Civil Engineering And Urban Planning (Ceup2016)

Civil Engineering And Urban Planning - Proceedings Of The 5th International Conference On Civil Engineering And Urban Planning (Ceup2016)
Author: Ahmed Mebarki
Publisher: World Scientific
Total Pages: 1378
Release: 2017-06-02
Genre: Technology & Engineering
ISBN: 9813225246

The 5th International Conference on Civil Engineering and Urban Planning (CEUP2016) was held in Xi'an, China on August 23 - 26, 2016. CEUP2016 gathered outstanding scientists and researchers worldwide to exchange and discuss new findings in civil engineering and urban planning associated with transportation and environmental topics. The conference program committee is also greatly honored to have four renowned experts for taking time off to present their keynotes to the conference.The conference had received a total of 410 submissions, which after peer review by the Technical Program Committee, only 108 were selected to be included in this conference proceedings, which covers Architecture and Urban Planning; Civil Engineering and Transportation Engineering.

Proceeding of the 3rd International Conference on Geotechnical Engineering for Disaster Mitigation and Rehabilitation 2011 Combined with the 5th International Conference on Geotechnical and Highway Engineering - Practical Applications, Challenges and Opportunities

Proceeding of the 3rd International Conference on Geotechnical Engineering for Disaster Mitigation and Rehabilitation 2011 Combined with the 5th International Conference on Geotechnical and Highway Engineering - Practical Applications, Challenges and Opportunities
Author:
Publisher: World Scientific
Total Pages: 699
Release: 2011
Genre: Civil engineering
ISBN: 9814365165

This proceedings contains 89 papers from 25 countries and regions, including 14 keynote lectures and 17 invited lectures, presented at the Third International Conference on Geotechnical Engineering for Disaster Mitigation and Rehabilitation (3ICGEDMAR 2011) together with the Fifth International Conference on Geotechnical & Highway Engineering (5ICGHE), which was held in Semarang, Indonesia, from 18 to 20 May 2011. This is the third conference in the GEDMAR conference series. The first was held in Singapore from 12 to 13 December 2005 and the second in Nanjing, China, from 30 May to 2 June 2008. The proceedings is divided into three sections : keynote papers, invited papers and conference papers under which there are six sub-sections : Case Studies on Recent Disasters; Soil Behaviours and Mechanisms for Hazard Analysis; Disaster Mitigation and Rehabilitation Techniques; Risk Analysis and Geohazard Assessment; Innovation Foundations for Rail, Highway, and Embankments; and Slope Failures and Remedial Measures. The conference is held under the auspices of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) Technical Committee TC-303 : Coastal and River Disaster Mitigation and Rehabilitation, TC-203 : Earthquake Geotechnical Engineering and Associated Problems, TC-302 : Forensic Geotechnical Engineering, TC-304 : Engineering Practice of Risk Assessment and Management, TC-213 : Geotechnics of Soil Erosion, TC-202 : Transportation Geotechnics, TC-211 : Ground Improvement, Southeast Asian Geotechnical Society (SEAGS), Association of Geotechnical Societies in Southeast Asia (AGSSEA), and Road Engineering Association of Asia & Australasia (REAAA).