Geotechnical engineering deals with soil and rock mechanics in various civil engineering applications. It involves understanding the behavior of earth materials, principles of soil and rock mechanics, and applications including underground structures, mining, transportation infrastructure, foundations, and retaining structures. Key aspects of geotechnical engineering include understanding soil properties, soil-structure interaction, slope stability, consolidation, and evaluating soil behavior under various loads such as earthquakes. Geotechnical analysis is important for foundation design, tunnel construction, machine foundations, offshore structures, and evaluating soil liquefaction potential.
This document provides information about a soil mechanics course including the course code, class details, textbooks, evaluation methods, instructor details, course objectives, syllabus, and exam schedule. The key points are:
1) The course covers soil properties, behavior, testing and applications in geotechnical engineering.
2) The instructor has a PhD from Northwestern University and experience in construction and consulting.
3) Evaluation includes quizzes, midterms, and a final exam. The syllabus covers topics like soil composition, permeability, stress distribution, consolidation, and shear strength.
This document discusses various index properties of soil and methods for determining them. It describes determining the specific gravity of soil through different methods like the pycnometer bottle method. It also discusses determining the in-situ dry density of soil using a core cutter and discusses particle size analysis through sieve analysis and sedimentation analysis. The document also describes determining the consistency limits of fine-grained soils, including the liquid limit and plastic limit tests. It defines the relative density of soils and provides categories of soil denseness based on relative density percentages.
This document describes an experiment to determine and prepare mud with a specific density using a mud balance. It aims to understand how to use a mud balance, how density changes with added barite, and how to recalculate densities. The procedure involves filling and weighing the cup on the balance to measure the mud's density in pounds per gallon. Factors like temperature, impurities, and mud/equipment quality can impact results. Mud density is important for functions like cutting transport, pressure control and preventing formation damage during drilling.
Determination of in situ density of soilSumanHaldar8
This document describes methods to determine the unit weight of soil. There are five types of unit weight: bulk, saturated, dry, submerged, and solid. The core cutter and sand replacement methods are explained. The core cutter method involves extracting a soil sample with a cutter, weighing it, and calculating bulk and dry unit weights. The sand replacement method involves using a calibrated container, pouring sand into an excavated hole to displace the soil, then weighing and calculating the soil's unit weight. Precautions for each method are provided.
This document describes various laboratory methods for determining soil properties, including liquid limit, plastic limit, and field density. The liquid limit can be found using a Casagrande apparatus or cone penetrometer, which measure the number of blows or penetration depth required for a soil sample to close a groove at different water contents. The plastic limit is the water content at which a soil thread crumbles. Field density is measured using a core cutter method or sand replacement method.
Index properties of soil and Classification of soils(Geotechnical engineering)Manoj Kumar Kotagiri
This document provides an overview of index properties and classification of soils. It discusses various index properties such as moisture content, specific gravity, density, particle size distribution, and consistency limits. Methods for determining these properties, such as oven drying, pycnometer, core cutter, and sieve and sedimentation analysis are described. Index properties are important for identifying soils and determining their engineering behavior and properties like strength, compressibility, and permeability.
This document provides information about a soil mechanics course including the course code, class details, textbooks, evaluation methods, instructor details, course objectives, syllabus, and exam schedule. The key points are:
1) The course covers soil properties, behavior, testing and applications in geotechnical engineering.
2) The instructor has a PhD from Northwestern University and experience in construction and consulting.
3) Evaluation includes quizzes, midterms, and a final exam. The syllabus covers topics like soil composition, permeability, stress distribution, consolidation, and shear strength.
This document discusses various index properties of soil and methods for determining them. It describes determining the specific gravity of soil through different methods like the pycnometer bottle method. It also discusses determining the in-situ dry density of soil using a core cutter and discusses particle size analysis through sieve analysis and sedimentation analysis. The document also describes determining the consistency limits of fine-grained soils, including the liquid limit and plastic limit tests. It defines the relative density of soils and provides categories of soil denseness based on relative density percentages.
This document describes an experiment to determine and prepare mud with a specific density using a mud balance. It aims to understand how to use a mud balance, how density changes with added barite, and how to recalculate densities. The procedure involves filling and weighing the cup on the balance to measure the mud's density in pounds per gallon. Factors like temperature, impurities, and mud/equipment quality can impact results. Mud density is important for functions like cutting transport, pressure control and preventing formation damage during drilling.
Determination of in situ density of soilSumanHaldar8
This document describes methods to determine the unit weight of soil. There are five types of unit weight: bulk, saturated, dry, submerged, and solid. The core cutter and sand replacement methods are explained. The core cutter method involves extracting a soil sample with a cutter, weighing it, and calculating bulk and dry unit weights. The sand replacement method involves using a calibrated container, pouring sand into an excavated hole to displace the soil, then weighing and calculating the soil's unit weight. Precautions for each method are provided.
This document describes various laboratory methods for determining soil properties, including liquid limit, plastic limit, and field density. The liquid limit can be found using a Casagrande apparatus or cone penetrometer, which measure the number of blows or penetration depth required for a soil sample to close a groove at different water contents. The plastic limit is the water content at which a soil thread crumbles. Field density is measured using a core cutter method or sand replacement method.
Index properties of soil and Classification of soils(Geotechnical engineering)Manoj Kumar Kotagiri
This document provides an overview of index properties and classification of soils. It discusses various index properties such as moisture content, specific gravity, density, particle size distribution, and consistency limits. Methods for determining these properties, such as oven drying, pycnometer, core cutter, and sieve and sedimentation analysis are described. Index properties are important for identifying soils and determining their engineering behavior and properties like strength, compressibility, and permeability.
The document provides an overview of geotechnical engineering and soil mechanics topics. It discusses several types of soil failures including slope stability, soil liquefaction, and soil settlement. Examples of historic landslides and soil failures are given. The roles and responsibilities of geotechnical engineers are outlined. Common soil tests and classification systems used in geotechnical engineering are described, including tests for moisture content, Atterberg limits, specific gravity, density, and compaction. Foundation types such as shallow foundations, deep foundations, individual footings, combined footings, and strip footings are also summarized.
soil stabilization using burnt municipal solid waste ash is done with varied test being carried out on different proportions of soil and additive which in our case is bottom ash and not fly ash
This document provides an introduction to geotechnical engineering concepts. It defines key terms like soil mechanics, rock mechanics, and geotechnical engineering. It discusses the importance of site investigation and characterization for engineering projects. It also outlines the scope and roles of a geotechnical engineer, including designing foundations, retaining structures, and slope stability assessments. The document lists common tasks of geotechnical engineers like pavement design, earth dams, and underground structure design. It emphasizes the importance of site investigation in enabling safe and economic project design by understanding ground conditions and material suitability.
This document provides an overview of key concepts in petroleum engineering, including permeability, geophysics techniques for oil and gas exploration like seismic surveys, and reservoir engineering essentials. It discusses permeability measurement methods, factors that affect permeability, and types of permeability. It also summarizes different geophysics techniques like seismic surveys, gravity surveys, electromagnetic surveys, and magnetic surveys. Finally, it outlines the essential elements and processes for hydrocarbon accumulation, including the need for a trap, reservoir, source rock, and seal.
The document discusses various methods for measuring soil permeability in the field, including pumping tests, percolation tests, slug tests, and infiltrometer tests using single or double rings. Pumping tests involve pumping water from a well and measuring drawdown over time to calculate permeability. Percolation tests passively measure the rate of water infiltration into soil over several hours. Slug tests quickly raise and lower the water level in a well to determine how quickly the water level returns to equilibrium. Single and double ring infiltrometers measure infiltration rates using rings inserted into the soil surface.
The document summarizes the properties of soil that are important for pavement design. It describes tests conducted to determine the soil's specific gravity, Atterberg limits, particle size distribution, optimum moisture content, maximum dry density, unconfined compressive strength, and permeability. The soil was found to have a liquid limit of 43%, plastic limit of 21%, and be classified as silt with 86% silt and 14% clay based on grain size analysis. The optimum moisture content was determined to be 14% with a maximum dry density of 1.72 g/cc. The unconfined compressive strength was also measured at different time intervals.
Goetechnical lab tests, atterberg limits tests Kamal Bhagat
The document discusses various methods used to characterize soils, including Atterberg limits, Proctor compaction testing, and field density testing.
The Atterberg limits—liquid limit, plastic limit, and shrinkage limit—describe the critical water content ranges where a fine-grained soil transitions between solid, semi-solid, plastic, and liquid states.
Proctor compaction testing involves compacting soil samples at different moisture contents to determine the optimum moisture content and maximum dry density for compaction.
Field density testing uses core cutter and sand replacement methods to directly measure the dry density of compacted soils in construction projects like embankments, highways, and railways.
The document discusses the dredging process and its effects. It provides an overview of different types of dredgers including mechanical dredgers like bucket ladder dredgers and grab dredgers, and hydraulic dredgers like suction hopper dredgers and cutter suction dredgers. It also discusses site investigation processes, soil classification, dredger selection, dumping grounds, effectiveness, impacts, and environmental effects of dredging. Dredging is necessary for activities like creating harbors and maintaining waterways, but can impact the environment through disturbed sediments and potential contamination. Careful planning is required to select the appropriate dredger and minimize negative impacts.
The document discusses various tests that are conducted on sand to determine its suitability for use in concrete. The key tests described are: moisture content, clay content, grain size distribution, permeability, strength, refractoriness, hardness, silt content, and bulking. These tests are important because sand properties like cleanliness, grain shape and size distribution influence the strength and durability of hardened concrete. Impurities in sand like silt or organic matter can weaken the final concrete.
This document discusses different methods for ground improvement (GI), including mechanical, hydraulic, and chemical modification techniques. Mechanical modification techniques aim to densify soils using external forces like compaction. Compaction increases soil strength and reduces compressibility, permeability, and liquefaction potential. Hydraulic modification techniques like dewatering and preloading are used to modify ground conditions by lowering the water table or accelerating consolidation. Preloading combined with vertical drains can shorten consolidation time in fine-grained soils. The document provides examples of different compaction and ground improvement equipment and methods.
Soil Stabilization, Soil Exploration, Foundation in expansive Soil.pdfabhishekgupta557534
The document discusses soil stabilization and provides methods to increase the strength and durability of soil. It describes mechanical methods like compaction and chemical methods like using calcium chloride, sodium silicate, bitumen, cement, and lime to stabilize different soil types. Foundation design for expansive soils is also covered, identifying tests to determine swelling potential and guidelines like providing impervious surfaces and drainage. Different soil exploration techniques like boreholes, probing, and sampling methods are outlined.
Class notes of Geotechnical Engineering course I used to teach at UET Lahore. Feel free to download the slide show.
Anyone looking to modify these files and use them for their own teaching purposes can contact me directly to get hold of editable version.
This document outlines the design of a flexible pavement for a 4km road in Quetta, Balochistan. The pavement will have a formation width of 24 feet with a 12 foot carriageway and 6 foot shoulders on each side. A 2 inch thick premix surfacing course will be used. The pavement layers will consist of a 6 inch base course and subbase with 9 inches of loose material below. Laboratory tests including the liquid limit, plastic limit, proctor test, and CBR test were conducted to inform the design. Based on a CBR value of 4%, the recommended layer thicknesses are 6 inches for the subbase, 6 inches for the base course, and 2 inches for the surface course. Drainage features
SUMMER TRAINING REPORTS OF SOIL TESTINGraish ansari
This document is a summer training report submitted by Mohd Raish Ansari to fulfill the requirements for a Bachelor of Technology degree in Civil Engineering from Babu Banarasidas University. It details a 4-week training conducted at the Geotechnical Engineering Directorate of RDSO, where the student learned various soil testing procedures as outlined in the Indian Standards for soil classification and compaction testing. The report includes an introduction, acknowledgements, procedures for common tests like moisture content, dry density, particle size distribution, liquid limit, plastic limit, and compaction. It emphasizes the importance of standardized testing for quality control on railway projects.
This document discusses soil mechanics and properties. It covers the origin and classification of soils, particle size distribution, indices like void ratio and specific gravity. Engineering properties like permeability, compressibility and shear strength are also mentioned. Different tests for soil classification like sieve analysis, hydrometer analysis, and Atterberg limits are described. Concepts of three phase diagrams, void ratio, porosity, degree of saturation and their relationships are explained. Engineering applications of void ratio are provided.
This document discusses methods for determining the water content, specific gravity, and in-situ unit weight of soils in a laboratory. It describes the oven-drying method as the most common and simplest way to determine a soil sample's water content. This involves drying the sample at 105-110°C for 24 hours. Other water content methods include the pycnometer, sand bath, rapid moisture meter, and torsion balance moisture meter techniques. Specific gravity is measured using a pycnometer/density bottle and is needed to compute void ratio and degree of saturation. In-situ unit weight can be found using either the core-cutter method or sand replacement method.
DSD-NL 2019 Anura3D ontwikkelingen - Analyse grote deformaties in de geotechn...Deltares
Presentatie door Mario Martinelli, Deltares, op de Geo Klantendag 2019, tijdens de Deltares Software Dagen - Editie 2019. Donderdag, 20 juni 2019, Delft.
SOIL MECHANICS INTRODUCTION WITH ADVANTAGES AND WHY SOIL MECHANICS STUDY IS S...MuhangiChristopher
This document provides an overview of soils and soil classification systems. It begins by discussing the unique nature of soils, including their heterogeneity, non-linear stress-strain properties, and anisotropy. Particle size distribution is then introduced as the basis for initial soil classification. Systems like the Unified Soil Classification System assign two-letter classifications based on percentages of sand, silt, and clay-sized particles and additional properties. For fine-grained soils, plasticity characteristics like the liquid limit and plastic limit are also important. The document outlines procedures for determining particle sizes and calculating parameters like the coefficient of uniformity used in soil classifications.
This document summarizes an experiment to determine the liquid limit of a soil sample. The experiment involved using a Casagrande apparatus to apply water to the soil sample and measure the moisture content at which the soil transitions from a plastic to liquid state. Graphs were included showing the relationship between moisture content and number of blows. The results found that the liquid limit obtained using the Casagrande apparatus was higher than when using a cone penetrometer method. The conclusion discussed that liquid limit is not entirely a physical property and is influenced more by sand particle size than shape.
The document provides an overview of geotechnical engineering and soil mechanics topics. It discusses several types of soil failures including slope stability, soil liquefaction, and soil settlement. Examples of historic landslides and soil failures are given. The roles and responsibilities of geotechnical engineers are outlined. Common soil tests and classification systems used in geotechnical engineering are described, including tests for moisture content, Atterberg limits, specific gravity, density, and compaction. Foundation types such as shallow foundations, deep foundations, individual footings, combined footings, and strip footings are also summarized.
soil stabilization using burnt municipal solid waste ash is done with varied test being carried out on different proportions of soil and additive which in our case is bottom ash and not fly ash
This document provides an introduction to geotechnical engineering concepts. It defines key terms like soil mechanics, rock mechanics, and geotechnical engineering. It discusses the importance of site investigation and characterization for engineering projects. It also outlines the scope and roles of a geotechnical engineer, including designing foundations, retaining structures, and slope stability assessments. The document lists common tasks of geotechnical engineers like pavement design, earth dams, and underground structure design. It emphasizes the importance of site investigation in enabling safe and economic project design by understanding ground conditions and material suitability.
This document provides an overview of key concepts in petroleum engineering, including permeability, geophysics techniques for oil and gas exploration like seismic surveys, and reservoir engineering essentials. It discusses permeability measurement methods, factors that affect permeability, and types of permeability. It also summarizes different geophysics techniques like seismic surveys, gravity surveys, electromagnetic surveys, and magnetic surveys. Finally, it outlines the essential elements and processes for hydrocarbon accumulation, including the need for a trap, reservoir, source rock, and seal.
The document discusses various methods for measuring soil permeability in the field, including pumping tests, percolation tests, slug tests, and infiltrometer tests using single or double rings. Pumping tests involve pumping water from a well and measuring drawdown over time to calculate permeability. Percolation tests passively measure the rate of water infiltration into soil over several hours. Slug tests quickly raise and lower the water level in a well to determine how quickly the water level returns to equilibrium. Single and double ring infiltrometers measure infiltration rates using rings inserted into the soil surface.
The document summarizes the properties of soil that are important for pavement design. It describes tests conducted to determine the soil's specific gravity, Atterberg limits, particle size distribution, optimum moisture content, maximum dry density, unconfined compressive strength, and permeability. The soil was found to have a liquid limit of 43%, plastic limit of 21%, and be classified as silt with 86% silt and 14% clay based on grain size analysis. The optimum moisture content was determined to be 14% with a maximum dry density of 1.72 g/cc. The unconfined compressive strength was also measured at different time intervals.
Goetechnical lab tests, atterberg limits tests Kamal Bhagat
The document discusses various methods used to characterize soils, including Atterberg limits, Proctor compaction testing, and field density testing.
The Atterberg limits—liquid limit, plastic limit, and shrinkage limit—describe the critical water content ranges where a fine-grained soil transitions between solid, semi-solid, plastic, and liquid states.
Proctor compaction testing involves compacting soil samples at different moisture contents to determine the optimum moisture content and maximum dry density for compaction.
Field density testing uses core cutter and sand replacement methods to directly measure the dry density of compacted soils in construction projects like embankments, highways, and railways.
The document discusses the dredging process and its effects. It provides an overview of different types of dredgers including mechanical dredgers like bucket ladder dredgers and grab dredgers, and hydraulic dredgers like suction hopper dredgers and cutter suction dredgers. It also discusses site investigation processes, soil classification, dredger selection, dumping grounds, effectiveness, impacts, and environmental effects of dredging. Dredging is necessary for activities like creating harbors and maintaining waterways, but can impact the environment through disturbed sediments and potential contamination. Careful planning is required to select the appropriate dredger and minimize negative impacts.
The document discusses various tests that are conducted on sand to determine its suitability for use in concrete. The key tests described are: moisture content, clay content, grain size distribution, permeability, strength, refractoriness, hardness, silt content, and bulking. These tests are important because sand properties like cleanliness, grain shape and size distribution influence the strength and durability of hardened concrete. Impurities in sand like silt or organic matter can weaken the final concrete.
This document discusses different methods for ground improvement (GI), including mechanical, hydraulic, and chemical modification techniques. Mechanical modification techniques aim to densify soils using external forces like compaction. Compaction increases soil strength and reduces compressibility, permeability, and liquefaction potential. Hydraulic modification techniques like dewatering and preloading are used to modify ground conditions by lowering the water table or accelerating consolidation. Preloading combined with vertical drains can shorten consolidation time in fine-grained soils. The document provides examples of different compaction and ground improvement equipment and methods.
Soil Stabilization, Soil Exploration, Foundation in expansive Soil.pdfabhishekgupta557534
The document discusses soil stabilization and provides methods to increase the strength and durability of soil. It describes mechanical methods like compaction and chemical methods like using calcium chloride, sodium silicate, bitumen, cement, and lime to stabilize different soil types. Foundation design for expansive soils is also covered, identifying tests to determine swelling potential and guidelines like providing impervious surfaces and drainage. Different soil exploration techniques like boreholes, probing, and sampling methods are outlined.
Class notes of Geotechnical Engineering course I used to teach at UET Lahore. Feel free to download the slide show.
Anyone looking to modify these files and use them for their own teaching purposes can contact me directly to get hold of editable version.
This document outlines the design of a flexible pavement for a 4km road in Quetta, Balochistan. The pavement will have a formation width of 24 feet with a 12 foot carriageway and 6 foot shoulders on each side. A 2 inch thick premix surfacing course will be used. The pavement layers will consist of a 6 inch base course and subbase with 9 inches of loose material below. Laboratory tests including the liquid limit, plastic limit, proctor test, and CBR test were conducted to inform the design. Based on a CBR value of 4%, the recommended layer thicknesses are 6 inches for the subbase, 6 inches for the base course, and 2 inches for the surface course. Drainage features
SUMMER TRAINING REPORTS OF SOIL TESTINGraish ansari
This document is a summer training report submitted by Mohd Raish Ansari to fulfill the requirements for a Bachelor of Technology degree in Civil Engineering from Babu Banarasidas University. It details a 4-week training conducted at the Geotechnical Engineering Directorate of RDSO, where the student learned various soil testing procedures as outlined in the Indian Standards for soil classification and compaction testing. The report includes an introduction, acknowledgements, procedures for common tests like moisture content, dry density, particle size distribution, liquid limit, plastic limit, and compaction. It emphasizes the importance of standardized testing for quality control on railway projects.
This document discusses soil mechanics and properties. It covers the origin and classification of soils, particle size distribution, indices like void ratio and specific gravity. Engineering properties like permeability, compressibility and shear strength are also mentioned. Different tests for soil classification like sieve analysis, hydrometer analysis, and Atterberg limits are described. Concepts of three phase diagrams, void ratio, porosity, degree of saturation and their relationships are explained. Engineering applications of void ratio are provided.
This document discusses methods for determining the water content, specific gravity, and in-situ unit weight of soils in a laboratory. It describes the oven-drying method as the most common and simplest way to determine a soil sample's water content. This involves drying the sample at 105-110°C for 24 hours. Other water content methods include the pycnometer, sand bath, rapid moisture meter, and torsion balance moisture meter techniques. Specific gravity is measured using a pycnometer/density bottle and is needed to compute void ratio and degree of saturation. In-situ unit weight can be found using either the core-cutter method or sand replacement method.
DSD-NL 2019 Anura3D ontwikkelingen - Analyse grote deformaties in de geotechn...Deltares
Presentatie door Mario Martinelli, Deltares, op de Geo Klantendag 2019, tijdens de Deltares Software Dagen - Editie 2019. Donderdag, 20 juni 2019, Delft.
SOIL MECHANICS INTRODUCTION WITH ADVANTAGES AND WHY SOIL MECHANICS STUDY IS S...MuhangiChristopher
This document provides an overview of soils and soil classification systems. It begins by discussing the unique nature of soils, including their heterogeneity, non-linear stress-strain properties, and anisotropy. Particle size distribution is then introduced as the basis for initial soil classification. Systems like the Unified Soil Classification System assign two-letter classifications based on percentages of sand, silt, and clay-sized particles and additional properties. For fine-grained soils, plasticity characteristics like the liquid limit and plastic limit are also important. The document outlines procedures for determining particle sizes and calculating parameters like the coefficient of uniformity used in soil classifications.
This document summarizes an experiment to determine the liquid limit of a soil sample. The experiment involved using a Casagrande apparatus to apply water to the soil sample and measure the moisture content at which the soil transitions from a plastic to liquid state. Graphs were included showing the relationship between moisture content and number of blows. The results found that the liquid limit obtained using the Casagrande apparatus was higher than when using a cone penetrometer method. The conclusion discussed that liquid limit is not entirely a physical property and is influenced more by sand particle size than shape.
This document outlines a short-term laboratory program at the National Central University from July 4-17, 2022 covering various engineering fields including structural, geotechnical, material, and environmental engineering. The program consists of lectures and demonstrations delivered by professors and graduate students focused on topics such as infrastructure monitoring using sensors, green pavement materials, centrifuge modeling, soil properties testing, and utilizing waste materials in concrete. Hands-on activities include image analysis of centrifuge tests and unmanned aerial vehicle data. The goal is to provide interdisciplinary training and research experiences to cultivate problem-solving skills for various hydrological and environmental challenges.
Tools & Techniques for Commissioning and Maintaining PV Systems W-Animations ...Transcat
Join us for this solutions-based webinar on the tools and techniques for commissioning and maintaining PV Systems. In this session, we'll review the process of building and maintaining a solar array, starting with installation and commissioning, then reviewing operations and maintenance of the system. This course will review insulation resistance testing, I-V curve testing, earth-bond continuity, ground resistance testing, performance tests, visual inspections, ground and arc fault testing procedures, and power quality analysis.
Fluke Solar Application Specialist Will White is presenting on this engaging topic:
Will has worked in the renewable energy industry since 2005, first as an installer for a small east coast solar integrator before adding sales, design, and project management to his skillset. In 2022, Will joined Fluke as a solar application specialist, where he supports their renewable energy testing equipment like IV-curve tracers, electrical meters, and thermal imaging cameras. Experienced in wind power, solar thermal, energy storage, and all scales of PV, Will has primarily focused on residential and small commercial systems. He is passionate about implementing high-quality, code-compliant installation techniques.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Height and depth gauge linear metrology.pdfq30122000
Height gauges may also be used to measure the height of an object by using the underside of the scriber as the datum. The datum may be permanently fixed or the height gauge may have provision to adjust the scale, this is done by sliding the scale vertically along the body of the height gauge by turning a fine feed screw at the top of the gauge; then with the scriber set to the same level as the base, the scale can be matched to it. This adjustment allows different scribers or probes to be used, as well as adjusting for any errors in a damaged or resharpened probe.
AI in customer support Use cases solutions development and implementation.pdfmahaffeycheryld
AI in customer support will integrate with emerging technologies such as augmented reality (AR) and virtual reality (VR) to enhance service delivery. AR-enabled smart glasses or VR environments will provide immersive support experiences, allowing customers to visualize solutions, receive step-by-step guidance, and interact with virtual support agents in real-time. These technologies will bridge the gap between physical and digital experiences, offering innovative ways to resolve issues, demonstrate products, and deliver personalized training and support.
https://www.leewayhertz.com/ai-in-customer-support/#How-does-AI-work-in-customer-support
Impartiality as per ISO /IEC 17025:2017 StandardMuhammadJazib15
This document provides basic guidelines for imparitallity requirement of ISO 17025. It defines in detial how it is met and wiudhwdih jdhsjdhwudjwkdbjwkdddddddddddkkkkkkkkkkkkkkkkkkkkkkkwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwioiiiiiiiiiiiii uwwwwwwwwwwwwwwwwhe wiqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq gbbbbbbbbbbbbb owdjjjjjjjjjjjjjjjjjjjj widhi owqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq uwdhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhwqiiiiiiiiiiiiiiiiiiiiiiiiiiiiw0pooooojjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj whhhhhhhhhhh wheeeeeeee wihieiiiiii wihe
e qqqqqqqqqqeuwiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiqw dddddddddd cccccccccccccccv s w c r
cdf cb bicbsad ishd d qwkbdwiur e wetwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww w
dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffw
uuuuhhhhhhhhhhhhhhhhhhhhhhhhe qiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc ccccccccccccccccccccccccccccccccccc bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbu uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuum
m
m mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm m i
g i dijsd sjdnsjd ndjajsdnnsa adjdnawddddddddddddd uw
Determination of Equivalent Circuit parameters and performance characteristic...pvpriya2
Includes the testing of induction motor to draw the circle diagram of induction motor with step wise procedure and calculation for the same. Also explains the working and application of Induction generator
Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
Supermarket Management System Project Report.pdfKamal Acharya
Supermarket management is a stand-alone J2EE using Eclipse Juno program.
This project contains all the necessary required information about maintaining
the supermarket billing system.
The core idea of this project to minimize the paper work and centralize the
data. Here all the communication is taken in secure manner. That is, in this
application the information will be stored in client itself. For further security the
data base is stored in the back-end oracle and so no intruders can access it.
1. Geotechnical Engineering
● Branch of civil engineering dealing with behavior of earth
materials.
● Principles of Soil mechanics + Rock Mechanics
● Wide range of applications in structures used in
● Military: Underground bunkers
● Mining: Excavation of coal mines
● Oil and natural gas exploration: Underground drilling
● Transportation: Roads, Railway lines including tunnels esp on
hilly terrains.
2. Importance of Geotechnical Engineering
● Soil is the ultimate foundation material which supports the
structure.
Leaning
Tower
of Pisa
3. Importance of Geotechnical Engineering
● Understanding stability of natural and manmade slopes
Mud
Sliding
in Sri
Lanka
Rock
Sliding
Mine Wall Failure
4. Importance of Geotechnical Engineering
● Tunnels, Conduits Konkan Railway Jan Shatabdhi
Express emerging
from a tunnel
5. Importance of Geotechnical Engineering
● Machine Foundations
● Dynamic Loading like earthquake, blast loading influence
soil behavior
Soil Liquefaction
6. Importance of Geotechnical Engineering
● Oil and Natural Gas industry
● Shale gas industry using hydraulic fracturing and principle of
rock mechanics.
● Offshore Platforms
Fracking
Crude oil price
Per barrel
June 2014: $107
6 months later
Jan 5 2015: $50
7. Importance of Geotechnical Engineering
● Soil-Structure Interaction
Process in which response of soil influences the structure
behavior and response of structure influence soil behavior.
Hanshin Expressway, Kobe Earthquake, Japan 1995
8. Importance of Geotechnical Engineering
● Earth retaining structures:, Wall with counterforts.
Cantilever wall, Gravity Walls – Determining Lateral loads.
● Construction material
9. Soil as 3 Phase Material
● Use of Classroom Board
10. Relationship
● S : Degree of Saturation = Vw/Vv
● e : Void Ratio = Vv/ Vs
● w : Water Content = ww/ws
● G : Specific Gravity
wG
G
w
w
G
V
V
V
V
G
V
V
V
V
V
V
Se
s
w
s
s
w
w
s
w
s
w
s
w
s
v
V
w
....
.....
....
....
....
wG
Se
11. Relationship
● Bulk Unit Weight, Dry Unit Weight
)
1
(
)
(
)
1
(
)
1
(
)
1
(
)
1
(
e
se
G
e
w
G
V
V
V
W
W
W
V
V
W
W
V
W
w
w
V
s
s
s
w
s
V
s
s
w
bulk
)
1
(
)
1
(
)
1
(
)
(
e
w
G
e
se
G w
w
bulk
)
1
( e
G
w
dry
12. Problem
● 1m3 of soil weighs 19.80 kN. The specific gravity of soil
particle is 2.70 and water content is 11%. Find void ratio,
dry density, degree of saturation
i) Using first principles.
ii) Using formulae
13. Problem
● The porosity of a soil sample is 35%.The specific gravity of
soil particles is 2.7. Calculate its void ratio, dry density,
saturated density, submerged density.
14. Phase Diagram for Soil
V W
Ww
Ws
Vw
Vs
Va
VV
Se
V
e
V
V
w
v
s
1
w
s
s
s
w
w
w
w
G
V
W
Se
V
W
16. Determination of water content
● Oven Drying Method
● Pycnometer Method
● Rapid Moisture Test Method
● Sand Bath Method
s
w
W
W
w
W
Ww
Ws
17. Oven Drying Method
● At temp > 110 deg.C, crystal structure of clay breaks down.
● For organic soils, temp is maintained at 60 deg.C
● W1: Wt. of Container
● W2: Container + Moist Soil
● W3: Container+ Oven Dried Soil
W2-W1
Ww
Ws
W3-W1
Ws
105-110 oC
24 hrs
3
2 W
W
Ww
1
3 W
W
Ws
18. Water Content: Pycnometer Method
W1
Empty
Container
W2
Container
+ Moist Soil
W3
Container
+ Moist Soil
+ Water
W4
Container
+Water
G of soil is known
19. Pycnometer Method: Phase Diagram
Moist Soil Moist Soil + Water Water
W2-W1
Ww
Ws
W3-W1
W4-W1
s
w W
W
W
W
)
( 1
2
w
s
s
s
s
G
W
W
V
)
(
)
( 1
4
1
3 W
W
V
W
W
W s
w
s
1
)
( 4
3
G
G
W
W
Ws
γwVs
20. Pycnometer Method
s
w W
W
W
W
1
2
1
)
( 4
3
G
G
W
W
Ws
1
)
( 1
2
s
s
w
W
W
W
W
W
w
1
1
)
(
)
(
4
3
1
2
G
G
W
W
W
W
w
21. Specific Gravity
● G is the ratio of specific gravity of the solid to the specific
gravity of water. It can obtained by measuring the weight of
solid to the weight of water occupying equivalent volume
of water.
w
s
w
s
G
22. Specific Gravity using Pycnometer
W1
Empty
Container
W2
Container
+Dry Soil
W3
Container
+ Dry Soil +
Water
W4
Container
+Water
23. Specific Gravity: Phase Diagram
Dry Soil
Dry Soil + Water Water
W2-W1
Ws
W3-W1 W4-W1
1
2 W
W
Ws
w
s
s
s
s
G
W
W
V
)
(
)
( 1
4
1
3 W
W
V
W
W
W s
w
s
24. Specific Gravity Calculations
1
)
( 4
3
G
G
W
W
Ws
1
)
( 4
3
1
2
G
G
W
W
W
W
)
(
)
(
)
1
(
1
4
3
1
2
4
3
1
2 W
W
W
W
G
G
W
W
G
W
W
G
)
(
)
( 4
1
3
2
1
2
W
W
W
W
W
W
G
26. In-Situ Unit Weight: Sand Replacement
Method
● Sand Replacement Method
● Hard, Gravely Soils
● Video
27. In-Situ Unit Weight Determination
● Water Displacement Method
● Cohesive Soil is weighed : W1
● It is coated with paraffin and weighed again: W2
● The system of soil coated with paraffin is now immersed in
water. The volume displaced is measured, Vdispl
Paraffin
displ V
V
V
paraffin
Paraffin
W
W
V
1
2
V
W1
28. Index Properties of Soil
● Tests carried out in order to classify a soil are classification
tests.
● The results obtained on the basis of these tests are alled
index properties of soil.
● Index properties of soil are divided into
● Soil Grain Properties
● Soil Aggregate Properties
29. Grain Shape
● Bulky Grains:
● All dimensions are more or less the same.
● Sandy and gravel soils.
● Formed by mechanical break-down of parent rocks.
● Angular Sub-Angular Sub-Rounded Rounded
transformation occurs during transportation
● Sphericity, De: Equivalent diameter of the particle, L is
length of the particle,
3
/
1
6
V
De
L
D
S e
30. Grain Shape
● Flaky Grains:
● One Dimension is very small compared to the remaining two
dimensions. Ex: A large sheet of paper.
● During sedimentation, these grains fall like leaves floating in air.
● Needle-Shape Grains
● One dimension of grain is fully developed and larger than other
two.
31. Engineering Characterization of Soils
Particle Size
fine-grained
Soil Plasticity
coarse-grained
Particle/Grain Size Distribution
Particle Shape
32. Grain Size Distribution
Why?
● Range of sizes of particles
● % of particles of each of the size ranges.
How?
● Sieve analysis for coarse fraction
● Sedimentation analysis for fine fraction.
34. Grain Size Distribution Curve
Particle Diameter D
% of
particles
(by wt)
finer than
Diameter
D
35. Grain Size Distribution Curve
● Well Graded
● Poorly Graded,
● Gap Graded,
● Uniformly Graded
● Effective Size
● Coefficient of Uniformity,
● Coefficient of Curvature
10
60
D
D
Cu
60
10
2
30
D
D
D
Cc
10
D
36. Sedimentation Analysis: Stoke’s Law
● v = Terminal Velocity
● D= Diameter of Sphere
● µ= Viscosity of Water
● Brownian Motion <0.0002 mm < D < 0.2 mm <Turbulence
● Assumptions: Spherical particle, Rate of fall not influenced
by adjacent particles, Average value of sp. Gravity G of
grains is used to calculate γs, Floc formation may occur
resulting in larger diameter of the particles.
2
18
D
v w
s
37. Sedimentation Analysis Hydrometer Method
● What is Hydrometer?
● Archimedes Principle: Hydrometer floats in the
suspension. The level of immersion depends on the
density of fluid.
● Gs= 1 + Rh/1000
● Rh= Reading of the Hydrometer
● Gs= Corresponding Specific Gravity
38. Calibration of Hydrometer: Effective depth L
and Hydrometer Reading R or L1,L2
j
h
j
h
A
V
A
V
L
L
L
2
2
2
1
39. Corrections to Hydrometer Reading
● Meniscus Correction, Cm >0
● Temperature Correction
● High Temp, Ct>0
● Low Temp, Ct<0
● Deflocculating agent correction, Cd>0
40. Procedure of Hydrometer Analysis
t Rh Rc L D N
15 sec - * *
30 sec - * *
1min - * *
2min - * *
5min - * *
10 min - * *
w
s
t
L
D
)
(
18
%
100
1
s
c
s
s
w
R
G
G
N
ws is weight of soil
grains in a soil of
suspension of
1000cc.
41. Stages of Consistency
● Consistency is a term which is used to describe the degree of firmness
of a soil using description such as soft , firm , stiff or hard. It indicates
the relative ease with which soil can be deformed.
The property of consistency is associated only with fine grained soils,
since fine grained soils are considerably influenced by the amount of
water content present in them. Depending on water content, the
following four stages are used to describe the consistency of clay soil :
● Liquid State
● Plastic State
● Semi-Solid State
● Solid State
● The boundary water contents at which soil undergoes changes from
one state to another are called “ consistency limits.”
42. Consistency Limits
Atterberg, a Swiss soil scientist first demonstrated the
significance of the consistency limits in 1911.
● Liquid Limit
● Plastic Limit
● Shrinkage Limit
43. Volume vs Moisture Content
liquid
Shrinkage
limit Plastic
limit
Liquid
limit
solid
semi-solid
plastic
Plasticity
Index
Volume
Water
Content
liquid
Shrinkage
44. Liquid Limit Test
● Cone Penetration Method
● Water Content at wα for which cone penetration α between
20mm and 30 mm is obtained
● Casagrande Liquid Limit Device
● Flow Index, If
● One Point Method
– Toughness Index.
)
15
)(
25
(
01
.
0
w
w
wL
48. Plastic Limit
● The moisture content at which a thread of soil just begins
to crack and crumble when rolled to a diameter of 3 mm
● Minimum water content at which change in shape of soil is
accompanied by visible cracks.
50. Indices
● Plasticity Index
● Consistency Index
● Liquidity Index
● Problem:
● A sample of soil with LL of 72.8 was found to have a
liquidity index of 1.21 and water content of 81.3. What are
its plastic limit and plasticity index? Comment on the
consistency of the soil.
PL
LL
PL
w
LI
PL
LL
w
LL
CI
PL
LL
PI
52. Shrinkage Limit
● Determination of G
w
s
w
s
W
W
V
V
V
W
G
2
1
1
2
,
)
( 2
1
1
2
W
W
V
W
G
w
53. Numerical on Shrinkage Limit
● In a shrinkage limit test, a container of volume 9.6cc was
filled with soil slurry. The weight of saturated soil was
17.46 g. The slurry was then dried, first in atmosphere and
then in oven at a constant temperature of 110 degC. The
wt and volume of the dried soil was 11.58g and 5.22 cc
respectively. Determine the shrinkage limit of the soil and
its shrinkage ratio.
54. Shrinkage Ratio, R
● R, Ratio of given change in volume of soil expressed as
% of dry volume to the corresponding volume change in
water content above the shrinkage limit.
● Volumetric Shrinkage, Vs
● Problem
2
1
2
1
100
W
W
V
V
V
R d
100
d
d
i
s
V
V
V
V
55. Activity of Clays
● Higher activity, more clay like behavior, higher swelling,
higher shrinkage, higher compressibility
● Graph
2
%
than
finer
Wt
PI
Activity
Activity Classification
< 0.75 Inactive
0.75-1.25 Normal
>1.25 Active
56. Activity of Clays
● Graph
Plasticity
Index
% finer than 2µ
Sodium
Montmorillnoite
(A=1.33)
57. Numerical on Activity of Clays
● Two Clays have the following characteristics. Calculate
their Activity Values. Compare their engineering behavior.
Clay A Clay B
LL 60 50
PL 25 30
% finer then
2µ
25 40
58. Numerical on clay behavior
● Two Clays have the following characteristics. Which of the
soil is more plastic? Which of them is softer in
consistency?
Clay A Clay B
LL 44 55
PL 20 35
Water content,
w
25 50
59. Unconfined Compressive Strength
● Explanation: Video
● Mohr’s Circle
Consistency Strength
kN/m2
Very Soft 25
Soft 25-50
Medium 50-100
Stiff 100-200
Very Stiff 200-400
Hard >400
60. Sensitivity
● Ratio of Unconfined compressive strength of an
undisturbed soil specimen to its unconfined strength after
remoulding.
remoulded
u
d
undisturbe
u
t
q
q
s
)
(
St Classification
1-4 Normal
4-8 Sensitive
8-15 Extra-Sensitive
> 15 Quick
61. Thixotropy
● Property of certain clays by virtue of which they regain
part of strength lost due to remoulding.
● Application: Driving pile foundations causes the soil to get
disturbed, the soil structure loses strength. After a month,
the soil regains part of its strength.
62. Classification of Soils
● Unified Soil Classification System
● Casagrande (1948) intended for use in airfield construction during
World-War II
● Coarse grain soils classified on the basis of GSD and fine grained
soils on the basis of plasticity characteristics
– Coarse-grained soils: Less than 50% passing through 75µ sieve
● Gravel: If more than 50% retained on 4.75 mm sieve
● Sand: More than 50% pass through 4.75mm sieve
– Fine Grained soils: Greater then 50% passing through 75µ sieve
● A-line of Plasticity Chart separates Clay and Silt.
● LL> 50 High Compressibility
● LL<50 Low Compressibility
63. Classification of Soils
● Unified Soil Classification System
Soil Type Prefix Sub Group Suffix
Gravel G Well graded W
Sand S Poorly graded P
Silt M Silty M
Clay C Clayey C
Organic O LL<50 L
Peat Pt LL>50 H
64. Classification of Soils
● AASHTO (American Association of State Highway Transport
Officials)
● Developed by US Bureau of Public Roads( now Federal Highway
Administration).
● Group Index, GI = 0.2 a + 0.0005 ac + 0.01 bd
a: min(% passing 75 µ -35, 75)
b: min(% passing 75 µ -15, 55)
c: min( LL-40, 60)
d: min(PI-10, 30)
GI =0 Good subgrade material,
GI> 20 Poor Subgrade material.
65. Classification of Soils
● INDIAN Soil Classification System
● 1959, Revised 1970.
● Based on USCS: Main Difference Fine Grained Soils
classified as Low, Medium and High Compressibility.
● Step by Step Procedure:
● Flow Chart
● A-line
66. Flow chart
>50%
Retained
on
75micron
sieve
Coarse grained
>50% Retained on
4.75mm sieve
Gravel Sand
% finer than 75
micron
< 5% >12% 5-12%
GSD LL, PL Test
GSD +
LL,PL Test
GW, SW, GP,
SP
GM, SM,
GC,SC,GM-
GC, SM-SC
GW-GM, GW-GC,GP-
GC, GP-GM, SW-SM,
SW-SC, SP-SC, SP-SM
Fine grained
LL, PL Test
Plasticity Chart
Below Above Hatched
Silt Clay Clay + Silt
LL<35 LL-35 to
50
LL>50
ML, MI, MH
CL, CI, CH
YES
YES
67. Soil Compaction
● Compaction vs Consolidation
● Laboratory Tests:
● Proctor Test, Modified Proctor Test
● Dry Density vs Moisture Content
● Zero Air Void Line
● Compactive Effort
● Types of Soil
● Compaction curve for sand
● Problem
70. Thought Experiment- 1
● Imagine you have a round plastic bottle in your hand.
● You pour round shaped pepper mint into it, many in number.
● Then you shake the bottle vigorously
● What happens to the pepper mints and the void space?
● Fill a small quantity of water in the plastic bottle.
● Again Add peppermints and shake the bottle?
● Do you require the same amount of effort now to reduce the
void space?
72. Compaction Advantages
● Grain to Grain Contact Increases—Increased shear
strength
● Reduces Permeability of Soil by decreasing the void
space.
● Increases bearing capacity of soil
● Prevents settlement of soil and undesirable volume
changes.
● Prevents build up of large pore pressures that cause soil
to liquefy under earthquakes.
73. Thought Experiment-2
● Take a rectangular sponge block.
● Immerse it in water for some time.
● Remove the sponge block and place it beside a measure
scale.
● Very Slowly start applying load on the sponge.
● What happens?
75. Compaction vs Consolidation
● Soil is always unsaturated
● Densification due to reduction
of air voids at a given water
content
● Instantaneous phenomenon.
● Occurs due to compaction
technique.
● Soil: Completely Saturated
● Volume reduction is due to
expulsion of water from voids
● Time-dependent phenomenon.
● Occurs due to load placed on
soil
76. Compaction Laboratory tests
Purpose
To determine the proper amount of mixing water to use when
compacting the soil in the field to achieve maximum density.
● RR Proctor :
● Standard Proctor Test,
● Modified Proctor Test
● IS equivalent of Standard Proctor Test is Light Compaction Test
● IS equivalent of Modified Proctor Test is Heavy Compaction Test
82. Test Procedure
● For different water content of soil, weight of the
compacted soil in the mould is measured.
● The dry weight is then determined as
● Plot: Max dry density-OMC
w
bulk
d
1
83. Test Procedure: Results
S>100% (impossible)
Zero air void curve (S=100%)
All compaction points should lie
to the left of ZAV curve
wopt
d max
Compaction Curve
84. Laboratory tests
IS Code Light
Compaction Test
Heavy Compaction
Test
Volume of Mould 1000 cc 1000 cc
Weight of Hammer 2.6 kg 4.9 kg
Drop of Hammer 310 mm 450 mm
Layers x Blows 3 layers x 25
blows
5 layers x 25 blows
Compaction Energy
per unit volume
? ?
85. Compactive Effort
With increasing compactive effort,
● What happens to γdmax?
● What happens to OMC?
● Given γ3
dmax> γ2
dmax > γ1
dmax and OMC3 <OMC2<OMC1
● Which is greater γ2
dmax- γ1
dmax or γ3
dmax- γ2
dmax ?
● What is greater OMC1 – OMC2 or OMC2 – OMC3 ?
● To which line is line joining the peak parallel to?
What does it mean?
86. Increasing in Compaction Effort
S>100% (impossible)
Zero air void curve (S=100%)
The Line joining the maximum is
parallel to the ZAV
wopt
d max
87. Zero Air-Void Line
● For a given soil, theoretically obtained maximum dry unit
weight for a soil at a given water content.
● Explanation using phase diagram
Air Voids reduce on application of compaction
energy and theoretically can reach zero
Zero
Air-Void
VW
Vs
Vs
Vw=VV
V
ww
ws
88. Zero Air-Void Line
● Derivation of Zero Air Void Line
from first principles for different
water content w
1
1
1
1
1
Gw
G
W
GW
G
W
V
G
G
V
G
V
G
G
V
V
G
V
V
V
G
V
W
w
s
w
w
s
w
w
w
s
w
v
w
w
s
v
w
s
v
s
w
s
d
Vs
Vw=VV
V
ww
ws
Zero Air-Void
89. Total Stress
● Stress = Force/Area
● Vertical Stress = Mass x g / Area
● Vertical Stress at depth h for soil of unit weight γ.
● Can be measured physically.
h
90. Pore Pressure
● Denoted by u
● Acts equally on all sides: Hydrostatic pressure
● Can be measured physically.
w
w
h
u
91. Effective Stress
● Denoted by
● Measure of intergranular stresses
● Mechanical behavior is linked to effective stress
● Shear Strength, Void Ratio, Compressibility
● Cannot be measured physically
u
92. Physical Meaning of Effective Stress
● Diagram
● Plane passing through points of inter-particle
contact.
● Resolving the forces into tangential T and normal N’
directions and equillibrium in Normal Direction
w
uA
N
P
'
u
A
P
A
N'
1
A
Aw
93. Problem 1
• Determine Neutral Stress and Total pressure at A,
B,C
Dry Sand, γ1= 18 kN/m3
Saturated Sand,
γ2 = 20 kN/m3
h1
h2
O
A
B
Saturated Clay,
γ3 = 21 kN/m3
h3
C
94. Problem 2
For the subsoil conditions shown in figure, plot the total, neutral and
effective stress distribution upto the bottom of the clay layer, when the
water table is at 2m below the ground surface (take S = 50% above the
water table).
Ground Surface
5m
4m
Sand
Gs=2.67
e = 0.6
Clay
γsat = 20 kN/m3
96. Capillary water in Soils
● What is surface tension?
● How does capillary rise of water takes place in soils?
● What is the effect of capillary rise in soils?
● Problem
97. Surface Tension
● Attractive forces/ Cohesive forces are present between
molecules. Those on the surface have no neighboring
atoms above, and exhibit stronger attractive forces upon
their nearest neighbors on the surface. This enhancement
of the intermolecular attractive forces at the surface is
called surface tension.
● Unit Force/Unit Length i.e N/m
98. Capillary Rise in pipette
d
T
h
w
c
4
• Derivation
hc
O
B
w
c
h
u
Negative Pore
Pressure
99. Capillary Rise in Soils
)
( u
• Negative pore water pressure
• Increase in effective stress
Ground Surface
Capillary rise in
soils
Partially
Saturated
Completely
Saturated
Negative
Pore
Pressure
Positive
Pore
Pressure
-
+
100. Problem
• For the subsoil conditions shown in the figure what are
the effective stress values at 1m, 2m and 4m depths.
Ground Surface
4m
Sand Saturated by capillary
action upto GS
Sand, e=0.2,
Gs=2.60
2m ?
sat
101. Permeability
● Permeability is a soil property which describes
quantitatively the ease with which soil allows water
to flow through it.
● More is the permeability, more is the ease with
water can flow through that soil.
● Permeability of Gravel > Sand > Silt > Clay.
Permeability decreasing with decreasing grain size.
102. Importance of permeability in soil mechanics
● Excavations of open cuts in sand below water table
● Seepage through earth embankment dams
● Subgrade drainage
● Rate of consolidation of compressible soils.
103. Fluid Mechanics Basics
● Bernoulli’s equation 2
2
2
2
1
2
1
1
2
2
z
g
V
p
z
g
V
p
Pressure Head h
p
w
Elevation Head z
Velocity Head g
V
2
2
2
2
1
1
2
2
1
1
z
h
z
h
z
p
z
p
V1
h2
z2
h1
z1
Q V2
Datum
104. Fluid Mechanics Basics
● Head Loss
2
2
2
2
1
2
1
1
2
2
z
g
V
p
z
g
V
p
HL
2
2
1
1
z
p
z
p
H
2
2
1
1 z
h
z
h
H
For Pipes of uniform cross-
section
h2
z2
h1
z1
Datum
H
105. Fluid Flow in Soils
● Darcy’s Law
H1
H2
Q
D V
H
L
A
L
H
Q
L
H
i
Hydraulic
Gradient
A
L
H
k
Q
ki
V
k is
Coefficient of
Permeability
107. Homework Problem
● Determine h2
Given:
Q = 1.82 cm3/sec
D = 6.18 cm
L = 25 cm
h2=30cm, z2=20 cm
z1=10 cm
K=0.1894 mm/sec
Q
h2
z2
h1
z1
H
108. Methods to measure permeability
● Laboratory:
● Constant Head Permeability Test
● Variable Head Permeability Test
● Field
● Unconfined Aquifer Test
● Confined Aquifer Test
110. Constant Head Permeability Test
● Pervious, Coarse Grained Soils
● K- Darcy’s Coefficient of Permeability, m/sec
● Q: Rate of Flow or Discharge, m3/sec
● L : Length, m
● A : Area of Cross –Section, m2
A
L
H
k
Q
A
H
QL
k
112. Variable Head Permeability Test
● Fine Grained Soils
● K- Darcy’s Coefficient of Permeability, m/sec
● h1: Height in standpipe at time t1
● h2: Height in standpipe at time t2
● L : Length, m
● a : Area of Cross –Section of Stand pipe, m2
113. Variable Head Permeability Test
)
(
ln 1
2
2
1
2
1
2
1
t
t
L
kA
h
h
a
dt
L
kA
h
dh
a
A
L
h
k
dt
dh
a
KiA
Q
t
t
h
h
2
1
1
2
ln
)
( h
h
t
t
A
aL
k
2
1
1
2
log
)
(
303
.
2
h
h
t
t
A
aL
k
114. Problem
● In a falling head permeability test, head causing flow was
initially 50 cm and it drops 2cm in 5 minutes. How much
time is required for the head to fall to 25 cm.
115. Homework Problem
● A falling head permeability test was performed on a sand sample and the
following data are recorded:
● Cross-sectional area of permeameter = 100 cm2; length of the soil sample
=15cm, area of stand pipe = 1cm2, time taken for the head to fall from 150
cm to 50 cm = 8 minutes, temperature of water = 25oC; dry mass of the
soil specimen = 2.2 kg and its Gs=2.68.
● Calculate its void ratio e25.
● Compute the coefficient of permeability of soil.
● What is the coefficient of permeability of the soil at void ratio of e20 =0.70
and standard temperature of 20oC?
Note: γw @25 oC = γw @20 oC,
µw @25oC =890/106 N sec/m2, µw @20oC =1002/106 N sec/m2.
w
w
e
e
k
1
3
116. Field Permeability Tests: Unconfined Aquifer
Impervious Boundary
z2
d2
z1
d1
Q dz
r1
r2
dr
r+dr
Z
r
121. Homework Problem
● For a field pumping test, a well was sunk through a
horizontal stratum of sand 14.5 m thick and underlain by a
impermeable clay stratum. Two observation wells were
sunk at horizontal distance of 16m and 34 m respectively
from the pumping well. The initial position of the water
table was 2.2 m below ground level. At steady state
pumping of 925 litres/minute, the drawdowns (depths
measured from water table) in the observation wells were
found to be 2.45 m and 1.20 m respectively. Calculate the
coefficient of horizontal permeability of the sand. Note:
1000 litre = 1m3.
122. Field Permeability Tests: Confined Aquifer
Impervious Boundary
z2
d2
z1
d1
Q H
r1
r2
dr
r+dr Q
dr
Impermeable Stratum
125. Problem
● Determine the pressure head, elevation head, total
head and head loss at the entering end, exit end
and point Xin the sample.
126. Consolidation Review
● Time Dependent Phenomenon
● Amount of Settlement = function (Time of Settlement)
● Our approach
● Total/ Final Settlement (Independent of Time)
● Intermediate Settlement ( Function of Time): Pore pressure
dissipation, Mechanics of Consolidation, Terzaghi’s 1-D
consolidation Theory
128. Amount of Settlement
● Total Settlement = Immediate Settlement+ Primary
Consolidation Settlement + Secondary Settlment
● Immediate Settlment: Negligible flow of water out of soil
mass and volume remains same, Occurs almost
immediately after the load is imposed
s
p
i
t S
S
S
S
129. ●Primary Consolidation
● Primary Consolidation: Squeezing out of pore water from
a loaded saturated soil causing a time dependent
decrease in volume
● Rate of Flow is controlled by permeability, compressibility,
pore pressure
● With passage of time, as pore pressures u dissipate, the
rate of flow will decrease and will eventually stop leading
to constant effective stress, signifying the end of primary
consolidation.
130. ●Secondary Consolidation
● The time dependent settlement exhibited by soils post
primary consolidation at constant effective stress.
131. Relationship between void ratio and primary
consolidation settlement
V0
s
V
V
V
e
0
s
V
V
V
e
1
1
)
(
V1
Vv
1
Vs
V
e
e
eV
V
V
e
V
S
W
o
o
S
0
0
0
1
1
1
Vv
0
Vs
0
0
1
0
1
1
0
1
1
V
e
e
V
e
V
V
V
S
W
S
S
132. Relationship between void ratio and primary
consolidation settlement
V
e
e
V
e
e
e
V
V
V
V
V
V
V
W
W
V
V
0
0
0
1
0
1
0
1
0
1
1
......
1
......
......
......
H
e
e
H
V
e
e
V
0
0
1
1
133. Problem
A compressible stratum is 6m thick and its void ratio is 1.70.
If the final void ratio after the construction of the building is
expected to be 1.61, what will be the probable ultimate
settlement of the building?
2
138. Problem
A clay soils tested in a consolidometer showed a decrease in
void ratio from 1.20 to 1.10 when pressure was increased
from 0.25 to 0.50 kgf/cm2.
a) Calculate the coefficient of compressibility and coefficient
of volume compressibility.
b) If the sample tested at a site was taken from a clay layer
3m in thickness, determine the consolidation settlement
resulting from the stress increment.
139. Definitions
Preconsolidation stress is the maximum stress the soil has ever
experienced.
A soil is said to be normally consolidated when the effective
stress is the maximum it has ever experienced in its stress
history i.e.
A soil is said to be over-consolidated if the current effective
stress is less than the preconsolidation stress i.e
pre
current
pre
current
max
pre
140. Role of Stress History
e
log
A
B
C
D
E H
J
Virgin
Compression
Curve
Re-Compression
Curve
Unloading
Curve
141. Role of Stress History
State B
3m
Maximum Stress
experienced by Soil
is
)
3
(
bulk
State A
Excavate
Soil
pre
e
log
A
B
)
3
(
log bulk
Unloadin
g
Current Stress
142. Role of Stress History
State A
Add Soil
back
State B
3m
Maximum Stress
experienced by Soil
is
)
3
(
bulk
pre
e
log
A
B
Re-loading
Current Stress
143. Role of Stress History
State B
3m
Virgin
Loadin
g
C
Maximum Stress
experienced by Soil
is q
bulk
)
3
(
State C
3m
qc
e
log
A
B
pre
Current Stress
144. Role of Stress History
Un-
Loading
C
Maximum Stress
experienced by Soil
is qc
bulk
)
3
(
E
State CDE
3m
q
State E
pre
e
log
A
B
D
Current Stress
145. Role of Stress History
Maximum Stress
experienced by Soil
is q
bulk
)
3
(
State E
State EHC
3m
q
pre
e
log
A
B
Re-
Loading
C
D
E
H
Current Stress
146. Role of Stress History
Maximum Stress
experienced by Soil
is q
bulk
)
3
(
State C
3m
qc
State F
3m
qc
qf
e
log
A
B
Virgin-
loading
C
D
E
F
Current Stress
pre
147. Over-Consolidation Ratio, OCR
e
log
A
B
C
D
E H
J
current
pre
OCR
Over Consolidation
OCR > 1, AB, CDE, EHC
Normal Consolidation
OCR = 1, BC and CJ
148. Consolidation Review
● Time Dependent Phenomenon
● Amount of Settlement = function (Time of Settlement)
● Our approach
● Total/ Final Settlement (Independent of Time)
● Intermediate Settlement ( Function of Time): Pore pressure
dissipation, Mechanics of Consolidation, Terzaghi’s 1-D
consolidation Theory
150. Mechanics of Consolidation
● Spring Piston Model
● A cylindrical vessel with compartments marked by pistons
separated by springs
● Pistons has perforations to allow water to flow through
● Piezometers inserted at middle of each compartment
● Space between springs filled with water.
152. Mechanics of Consolidation
● Apply pressure on the top most piston.
● Immediately on application of load,
● Length of springs remain unchanged
● As a result, the entire is borne by water in the vessel.
is the excess hydrostatic pressure
● Initial rise in water level
u
w
h
154. Mechanics of Consolidation
● After time t, flow of water through the perforations has
begun at upper compartments. There is a corresponding
decrease in volume, the upper springs have compressed
a little.
● They carry portion of applied loads and a drop in pressure
occurs. The isochrone for t=t1 represents the pore
distribution at upper and lower compartments.
156. Mechanics of Consolidation
● As time progresses, the springs in the lower
compartments are also compressed leading to increase in
and drop in
● Finally after long time, excess pore pressure
drops to zero and the entire load is carried by springs.
u
u
161. Mechanics of Consolidation
● The decrease in soil volume by the squeezing out of pore
water on account of gradual dissipation of excess
hydrostatic pressure induced by an imposed total stress is
called consolidation.
162. Terzaghi’s 1-D Theory of Consolidation
● A Theory to predict the pore pressures at any elapsed time and at any location is
required to predict the time rate of consolidation of a consolidating layer.
● Assumptions:
1. Compression and flow is 1-D
2. Darcy’s Law is valid
3. Soil is homogeneous and completely saturated
4. Soil grains and water are both incompressible
5. Strains are small. Applied del sigma produce virtually no changes in thickness,
6. k, av are constant.
7. No secondary compression.
164. Terzaghi’s 1-D Theory of Consolidation
● Continuity Equation
● Darcy’s Law
● Continuity Equation
becomes
t
w
v
t
w
dV
z
v
y
v
x
v z
y
x
t
w
dV
z
vz
z
u
k
z
h
k
v
w
z
z
z
t
w
dV
z
u
k
w
z
2
2
165. Terzaghi’s 1-D Theory of Consolidation
● Change in Volume and void ratio
t
e
e
dV
t
w
0
1
dV
t
u
e
a
dV
z
u
k V
w
z
0
2
2
1
du
a
d
a
de
V
V
....
t
u
z
u
a
e
k
V
w
z
2
2
0 )
1
(
t
u
z
u
CV
2
2
166. Boundary and Initial Conditions
2H
IC : At t =0 , u = ui
At z=2H,
u=0 for t>0
At z=0,
u=0 for t>0
t=0
t>0
u
ui
z=2H
z=0
168. Drainage path ratio Z=z/H
What is value of the length of drainage path H?
● The maximum distance the water has to travel to reach
the drainage surface is used as H in Terzaghi’s 1-D
solution.
● t is the thickness of the consolidating layer.
● Depending on drainage conditions, H is taken as t (Single
drainage) and t/2(double drainage)
169. Types of Drainage
● Double Drainage
● H= t/2
● Single Drainage
● H=t
Sand
Sand
Clay
t
Drainage
Surface
Drainage
Surface
Impervious
Sand
Clay
t
Drainage
Surface
170. Time factor Tv
● Tv = Cv t/ H2, Time Factor
● The time required for a soil to reach a given degree of
consolidation is directly proportional to the square of the
length of the drainage path and inversely proportional to
the coefficient of consolidation.
171. Degree of Consolidation
t0 t2
u
ui
z
u
z
i
z
i
Z
u
u
u
U
Degree of
Consolidation
● Represents the stage of
consolidation at a certain location
in the consolidating layer.
● Ratio of dissipate pore pressure
by initial pore pressure at a given
location.
172. Solution of the pde
0
2
1 )
(
)
(
1
n
V
Z T
f
Z
f
U
H
z
Z
z
U
V
T
173. Average Degree of Consolidation
u
ui
z
u
z
Total
Hatched
U
H
z
Z
z
U
Excess pore
pressure
remaining
Pore
Pressure
Dissipated
At t =0,
Hatched = 0
U=0
At t infinity,
Hatched = Total
U=1
Pressure
Pore
Initial
Dissipated
Pressure
Pore
U
174. Taylor’s simplified Solution
● U is average degree of consolidation.
● Tv is the time factor
%
60
%),
100
log(
933
.
0
781
.
1
%
60
,
4
2
U
U
U
U
TV
175. Terzaghi’s 1-D Theory of Consolidation Summary
● Cv is coefficient of consolidation, Units m2/sec or m2/day
● Boundary Conditions and Initial Conditions
● Non-dimensional Factors
● Z=z/H, Drainage path Ratio
● Tv = Cv t/ H2, Time Factor
● Degree of Consolidation or Consolidation ratio at given z
● U: Average degree of Consolidation
at a given time t
Pressure
Pore
Initial
Dissipated
Pressure
Pore
U
i
z
i
Z
u
u
u
U
176. Problem
● A 8m thick clay layer with single drainage settles by 120mm in
2 years. The coefficient of consolidation for this clay was
found to be 0.006 cm2/sec. Calculate the likely ultimate
consolidation settlement and find out how long it will take to
undergo 90% of this settlement.
177. Problem
● A certain clay layer has thickness of 5m. After 1 year, when
the clay was 50% consolidated, 8cm of settlement has
occurred. For a similar clay and loading conditions, how much
settlement would occur at the end of 1 year and 4 years
respectively, if thickness of new layer were 25m?
178. Problem
● In a laboratory consolidation test on a 20mm thick sample of
saturated clay taken from a site, 50% consolidation was
reached in 10 minutes. Estimate the time required for clay
layer 5m thickness at site for 50% consolidation if drainage is
only towards the top. Assume the laboratory sample and clay
layer are subjected to same increase in stress. How much
time is required for clay layer for 50% consolidation. How
much time is required to reach 50% consolidation for double
drainage of clay layer?
179. Homework Problem
1. A normally consolidated clay settled by 20 mm when the
effective stress was increased from 25 to 50 kN/m2. What
will be its settlement when the effective stress is increased
from 50 to 100 kN/m2?
187. Mechanism of Shear Resistance
● Friction
● Interlocking of particles contributes appreciably to
frictional resistance
188. Mohr-Coulomb Failure Criterion
● According to Mohr’s failure theory, the materials fail when
the shear stress on the failure plane at failure reaches a
value which is unique function of the normal stress on
that plane.
189. Mohr Coulomb Failure Envelope
O
)
( ff
ff f
3
1
)
,
( ff
ff
N
190. Mohr Coulomb Failure Envelope
O
)
( ff
ff f
3
1
)
,
( ff
ff
N
191. Mohr Coulomb Failure Envelope
O
)
( ff
ff f
3
f
1
)
,
( ff
ff
N
192. Mohr Coulomb Failure Envelope
O
)
( ff
ff f
3
f
1
)
,
( ff
ff
N
196. Problem
● Determine the shear strength in terms of effective stress
on plane within a saturated soil mass at a point where the
total normal stress is 200kN/m2 and the pore water
pressure is 80 kN/m2. The effective shear strength
parameters for the soil are
c’=2kN/m2, Φ = 30deg
197. Problem
● The stress at failure on a failure plane in a cohesionless
soil were Normal Stress=15 kN/m2, Shear Stress = 6
kN/m2. Determine the angle of internal friction of soil,
major and minor principal stresses.
198. Direct Shear Test
● Metal box of square cross-section split into two halves
approximately.
● Shear is applied at constant rate.
● Shear load vs shear deformation for different vertical load.
( σ,τ) at failure determined.
● Failure Shear stress for given normal stress determined.
● The test is repeated for different normal stresses.
199. Direct Shear Test
O
N
)
tan(
N
c
3
f
1
4
)
,
( ff
ff
N
c
c: Cohesion
Angle
Friction
:
Total Stress
3
)
,
( ff
ff
N
2
)
,
( ff
ff
N
1
)
,
( ff
ff
N
200. Problem
● The following data was obtained from direct shear test.
Normal Pressure= 20kN/m2, Tangential Pressure = 16
kN/m2. Angle of internal friction = 30o, cohesion= 4 kN/m2.
Represent the data on the Mohr’s circle and compute the
principal stresses.
201. Direct Shear Test
● Advantages
● Quick, Inexpensive Test.
● Ease of preparation of sample
● Disadvantages
● Drainage conditions cannot be controlled
● Pore water pressure cannot be measured
● Failure plane is always horizontal
● Not suitable for fine-grained soils for which drainage
conditions play an important role.
202. Advantages of Triaxial Test
● Most versatile of all shear testing methods.
● Drainage conditions can be controlled..
● Pore water measurements can be made accurately.
● Failure plane is not forced.
203. Triaxial Test
● Test Procedure
● Types of Triaxial Test
● Unconfined Compression Test
204. Test Procedure
● Cylindrical specimen placed on porous disc resting on pedestal of
triaxial cell
● Specimen enclosed in rubber membrane and sealed to the pedestal
at the bottom as well as to the loading cap at the top by rubber O-
rings.
● Triaxial cell is filled with water at required pressure. This all round
pressure is called cell pressure or confining pressure. It acts
radially on the vertical surface and on the top and bottom surfaces.
● With Cell pressure held constant, additional axial stress is applied
through the ram gradually until the sample fails at an additional axial
stress σa.
205. Measurements made in Triaxial Test
● Axial strain is determined by measuring the change in length
using either a dial gauge or a displacement transducer.
● Pore water measuring apparatus used to measure pore
pressure operated only under conditions of no flow by closing
the valve in the drainage line.
● If development of pore water pressure is not allowed, the
valve in the pore water line is closed and the valve in the
drainage line is opened. Thus allowing flow of water from the
soil through the drainage line into a burrette attached to this
line. The volume of water expelled from the specimen is
measured in burrette.
206. Stages of Loading
● 1st Stage is Application of Cell pressure
● 2nd Stage is Application of Axial Load
N
1
3
1
3
3
3
3
3
1ST Stage 2nd Stage
207. Types of Triaxial Test
1 st Stage ( Application
of Cell Pressure)
2nd Stage (Application of
Axial Load to Failure)
UU Test No Drainage,
No Consolidation
UNCONSOLIDATED
No Drainage
UNDRAINED
CU Test Drainage Allowed
Consolidation takes place
CONSOLIDATED
No Drainage
UNDRAINED
CD Test Drainage Allowed
Consolidation takes place
CONSOLIDATED
Drainage Allowed
DRAINED
208. Types of Triaxial Test
● UU: Unconsolidated Undrained Test
● Takes 15 minutes to complete
● Enables determination of Cu, Φu.
● CU: Consolidated Undrained Test
● Measures total stress parameters Ccu, Φcu and effective
stress parameters C’cu, Φ’cu .
● Takes 24 hours for consolidation 1st stage and 2hour for
axial loading to failure 2nd stage.
209. Types of Triaxial Test
● CD: Consolidated Drained Test
● Measures effective stress parameters C’cu, Φ’cu .
● Very Slow and takes upto 2 weeks
● Unconfined Compression Test
● Cell pressure applied is zero. First stage loading is zero.
● Cu= qu/2
● Φu = 0.
210. Vane Shear Test
● Why is it used?
● For measuring shear resistance of soft saturated clay deposits
in the field directly by pushing the vane directly into the soil
upto required depth and applying torque.
● This overcomes the difficulty of obtaining undisturbed soil
sample whose shear strength may alter significantly during the
process of sampling and handing.
211. Problem
● In an in situ vane shear test on a saturated clay, a torque
of 35 N.m was required to shear the soil. The diameter of
the vane was 50mm and length 100mm. Calculate the
undrained shear strength of clay.
● The vane was rotated rapidly to cause remoulding of soil.
The torque required to shear the soil in remoulded state
was 5kNm. Determine the sensitivity of clay.