This document provides an overview of expansive soils, including their mineral composition, interaction with water, and identification and treatment. Key points include:
- Expansive soils like clay can swell up to 30% when absorbing water due to their small particle size and large surface area.
- Important clay minerals include kaolinite, montmorillonite, and illite, which differ in their layered crystal structure and water absorption properties.
- Identification methods include tests of free swell percentage, differential free swell, and swelling pressure.
- Treatment options are soil replacement, moisture barriers, soil stabilization techniques like lime or cement addition, and specialized foundation designs isolated from swelling soils.
This document discusses expansive soils and provides information on their identification and treatment. It defines expansive soils as those that swell considerably when water is absorbed and shrink when water is removed. It describes the different mineral content that makes up clay soils, including tetrahedral and octahedral sheets. Methods for identifying expansive soils include mineralogical identification using X-ray diffraction and differential thermal analysis, as well as physical property tests like free swell, differential free swell, and swelling pressure. Foundations on expansive soils require special treatment to prevent damage from swelling.
Expansive soil & its improvement techniquesUmarSaba1
The document discusses expansive soils, which are soils that swell significantly when water is absorbed and shrink when water is removed. It identifies different types of clay minerals that make up expansive soils, including kaolinite, montmorillonite, and illite. It describes various tests used to identify and characterize expansive soils, such as free swell tests, differential free swell tests, and swelling pressure tests, which measure how much the soil expands with water and the pressure required to prevent expansion.
This document summarizes the properties and types of soil colloids. It discusses the general properties of soil colloids including their small size, large surface area, surface charges, adsorption of cations and water, cohesion, adhesion, swelling, dispersion, and brownian movement. It describes the four major types of soil colloids - layer silicate clays, iron and aluminum oxide clays, allophane, and humus. Layer silicate clays are further classified into 1:1, 2:1, and 2:1:1 types depending on their crystal structure, with descriptions of common clay minerals in each type.
This document discusses expansive soils and stabilization methods. It describes how certain clay minerals like smectite swell when they absorb water and shrink when drying. This swelling and shrinking can damage structures by causing heaving, differential settlement, and fissures. The document outlines engineering issues with expansive soils and various stabilization and remedial measures to mitigate problems. These include removing expansive soils, mixing in non-expansive materials, treating with lime or polymers, installing proper drainage, and using thick foundation slabs or piling. Case studies of damages from expansive soils in different countries are also presented.
Soil colloids are very small organic and inorganic particles present in soil that determine its physical, chemical, and fertility properties. The four major colloid types are: 1) clay minerals like silicates, 2) iron and aluminum oxides, 3) allophane and amorphous clays, and 4) humus. Soil colloids influence soil properties through their large surface area, electric charge, and ability to undergo ion exchange with cations in the soil solution. The cation exchange capacity measures the ability of soil colloids to hold exchangeable cations and influences soil fertility and nutrient retention. Maintaining optimal soil pH through liming is important for nutrient availability and crop growth.
This document provides an introduction to soil engineering and the basic units that form soils. It discusses how soils are formed and classified. Specifically, it examines the molecular structure of clay minerals, including how they are composed of tetrahedral and octahedral units that form micelles. It describes the key differences between 1:1 clay minerals like kaolinite and 2:1 clay minerals like illite and montmorillonite.
This document discusses clay minerals and soil structure. It begins by explaining the origin of clay minerals from the weathering of rocks by water and defines the basic units of clay minerals including silica tetrahedra and octahedral sheets. It then describes various common clay minerals like kaolinite, montmorillonite, illite, vermiculite and chlorite. The document also covers methods to identify clay minerals including x-ray diffraction and differential thermal analysis. It discusses specific surface area of clay minerals and how water interacts with clay particles and balances their charge deficiencies. Soil structure and different soil fabrics are briefly introduced.
Clay minerals are composed of silicon and aluminum structural units that form tetrahedral and octahedral sheets. Different combinations of these sheets create different clay minerals, such as kaolinite, montmorillonite, illite, and chlorite. Montmorillonite has a very high specific surface area and cation exchange capacity, allowing it to easily absorb water between its sheets and expand greatly in volume. This makes montmorillonite a highly reactive clay that is commonly used as a drilling mud.
This document discusses expansive soils and provides information on their identification and treatment. It defines expansive soils as those that swell considerably when water is absorbed and shrink when water is removed. It describes the different mineral content that makes up clay soils, including tetrahedral and octahedral sheets. Methods for identifying expansive soils include mineralogical identification using X-ray diffraction and differential thermal analysis, as well as physical property tests like free swell, differential free swell, and swelling pressure. Foundations on expansive soils require special treatment to prevent damage from swelling.
Expansive soil & its improvement techniquesUmarSaba1
The document discusses expansive soils, which are soils that swell significantly when water is absorbed and shrink when water is removed. It identifies different types of clay minerals that make up expansive soils, including kaolinite, montmorillonite, and illite. It describes various tests used to identify and characterize expansive soils, such as free swell tests, differential free swell tests, and swelling pressure tests, which measure how much the soil expands with water and the pressure required to prevent expansion.
This document summarizes the properties and types of soil colloids. It discusses the general properties of soil colloids including their small size, large surface area, surface charges, adsorption of cations and water, cohesion, adhesion, swelling, dispersion, and brownian movement. It describes the four major types of soil colloids - layer silicate clays, iron and aluminum oxide clays, allophane, and humus. Layer silicate clays are further classified into 1:1, 2:1, and 2:1:1 types depending on their crystal structure, with descriptions of common clay minerals in each type.
This document discusses expansive soils and stabilization methods. It describes how certain clay minerals like smectite swell when they absorb water and shrink when drying. This swelling and shrinking can damage structures by causing heaving, differential settlement, and fissures. The document outlines engineering issues with expansive soils and various stabilization and remedial measures to mitigate problems. These include removing expansive soils, mixing in non-expansive materials, treating with lime or polymers, installing proper drainage, and using thick foundation slabs or piling. Case studies of damages from expansive soils in different countries are also presented.
Soil colloids are very small organic and inorganic particles present in soil that determine its physical, chemical, and fertility properties. The four major colloid types are: 1) clay minerals like silicates, 2) iron and aluminum oxides, 3) allophane and amorphous clays, and 4) humus. Soil colloids influence soil properties through their large surface area, electric charge, and ability to undergo ion exchange with cations in the soil solution. The cation exchange capacity measures the ability of soil colloids to hold exchangeable cations and influences soil fertility and nutrient retention. Maintaining optimal soil pH through liming is important for nutrient availability and crop growth.
This document provides an introduction to soil engineering and the basic units that form soils. It discusses how soils are formed and classified. Specifically, it examines the molecular structure of clay minerals, including how they are composed of tetrahedral and octahedral units that form micelles. It describes the key differences between 1:1 clay minerals like kaolinite and 2:1 clay minerals like illite and montmorillonite.
This document discusses clay minerals and soil structure. It begins by explaining the origin of clay minerals from the weathering of rocks by water and defines the basic units of clay minerals including silica tetrahedra and octahedral sheets. It then describes various common clay minerals like kaolinite, montmorillonite, illite, vermiculite and chlorite. The document also covers methods to identify clay minerals including x-ray diffraction and differential thermal analysis. It discusses specific surface area of clay minerals and how water interacts with clay particles and balances their charge deficiencies. Soil structure and different soil fabrics are briefly introduced.
Clay minerals are composed of silicon and aluminum structural units that form tetrahedral and octahedral sheets. Different combinations of these sheets create different clay minerals, such as kaolinite, montmorillonite, illite, and chlorite. Montmorillonite has a very high specific surface area and cation exchange capacity, allowing it to easily absorb water between its sheets and expand greatly in volume. This makes montmorillonite a highly reactive clay that is commonly used as a drilling mud.
Clay Minerology & Plasticity Characteristics of SoilArbaz Kazi
This presentation describes about various states of soil, plasticity of soil, various clay minerals, consistency limits, structure of clay minerals, classification of clay minerals based on Activity number
The document discusses clay minerals and their interaction with water. It describes how clay minerals are formed from the weathering of rocks by water. The basic units of clay minerals are silica tetrahedra and octahedral sheets. Clay minerals can have 1:1, 2:1, or 2:1:1 layer structures. Clay particles have negative charges due to isomorphic substitution and broken bonds. Polar water molecules form hydrogen bonds with clay surfaces, becoming tightly bound in monolayers.
This document presents information on clay minerals. It begins with an introduction stating that clay minerals are formed through chemical weathering and are found in shales. It then discusses the basic structural units of clay minerals, which are tetrahedral and octahedral sheets. The document outlines different types of bonding in clay minerals and provides a classification of clay minerals including kaolinite, halloysite, montmorillonite and illite. In conclusion, it restates that clay minerals are layer silicates formed by weathering and describes their layered atomic structure and different bonding types.
This case study analyzed clay occurrences around Kutigi Central Bida Basin in Nigeria. Detailed field mapping identified two hills near Kutigi town containing clay deposits. Laboratory analysis of samples from the hills using X-ray diffraction found them to be composed primarily of kaolinite and quartz minerals. Kaolinite alone constituted about 43.64% of the samples, while quartz constituted around 54.55%. This study characterized the geology and mineralogical composition of clays in this region of Nigeria.
This document discusses clay minerals and their identification. It begins by explaining the origin of clay minerals from the weathering of parent rocks by water. The main clay minerals are then described, including their chemical composition, crystal structure, and properties. Kaolinite, illite, montmorillonite and other clay minerals are 1:1, 2:1, and 2:1:1 layer silicates with different bonding and swelling capabilities. Identification methods for clay minerals are also summarized, such as x-ray diffraction to determine crystal spacing, differential thermal analysis to observe temperature reactions, and other techniques.
The chemistry of clay in the drilling industryAnushka112464
The chemistry of clay in the drilling proceedings and the various kinds of clay structures that can be formed and used in the industry. This could for various purposes and take into consideration several factors. The pdf goes through these in good detail. It also contains numericals pertaining to the aforementioned topics. It also provides the reader with the solution. It is well illustrated and contains the necessary graphs.
The chemistry of clay in the drilling proceedings and the various kinds of clay structures that can be formed and used in the industry. This could for various purposes and take into consideration several factors. The pdf goes through these in good detail. It also contains numericals pertaining to the aforementioned topics. It also provides the reader with the solution. It is well illustrated and contains the necessary graphs.
Clay mineralogy involves studying the structure and properties of clay particles at the microscopic and atomic scales. There are three main types of clay minerals - kaolinite, montmorillonite, and illite. All clay minerals have a basic structure consisting of a silica tetrahedral sheet bonded to an aluminum octahedral sheet. Kaolinite has a thickness of 7.2 angstroms while montmorillonite is thicker at 10 angstroms due to water and ions between its layers. Clays have a large surface area and interact strongly with water due to their surface charge and layered structure. Soil structure depends on particle size and arrangement - coarse soils have single grains while clays can be dispersed or flocculated
Clay minerals are hydrous aluminum silicates that form in soils, sediments, and by alteration of rocks. They have a layered structure composed of silicon tetrahedra and aluminum octahedra sheets. The main clay minerals are kaolinite, illite, smectite (including montmorillonite), chlorite, and vermiculite. Kaolinite has a 1:1 layered structure while illite, smectite, and chlorite are 2:1 layered phyllosilicates. Smectite has expandable interlayers that absorb water. Clay minerals are important constituents of soils and sediments and have various industrial uses such as in drilling muds, ceramics, and environmental
The document discusses key properties and composition of soil. It describes how soil properties are determined by geological material, vegetation, weathering over time, topography, and human activities. It focuses on the chemical properties of soil, especially cation exchange capacity (CEC) which is important for soil fertility. CEC is the ability of soil to retain exchangeable cations like calcium, magnesium, potassium and sodium which are important for plant nutrition. Factors that influence CEC include the type and amount of clay minerals and organic matter in the soil.
CLASSIFICATION, STRUCTURE, CHEMICAL COMPOSITION AND PROPERTIES OF CLAY MINERA...BarathKumar163434
Soil clays can exist in crystalline, structurally disordered or amorphous form.
Amorphous : has no recognizable shape or geometrical internal arrangement of atoms
Crystalline: atomic arrangement repeated at regular pattern in 3 dimensional directions
spatial arrangement of atoms producing building unit of a crystal is called the unit cell
By placing several unit cells together, the crystal arrangement produced is then called a lattice structure
unit cells has a volume of approximately 1µm3
packing of silica tetrahedran and aluminum octahedran sheets, forms a layered clay structure
the total assembly of a layer plus interlayer material is called an unit structure
A comparative study on adsorption behavior of heavy metal elements onto soil ...Andre Zeitoun
1) The document examines the adsorption behavior of heavy metal elements from an acid solution onto common soil minerals (illite, halloysite, zeolite, goethite) over various time periods.
2) The results show that the adsorption extent of elements varies depending on the mineral type and reaction time, with Fe and As being significantly removed within an hour.
3) Overall, halloysite was found to be the most effective adsorbent, though adsorption of alkali elements did not follow predictions based on ionic radii.
11.application of appopolite in adsorption of heavy metals (co and ni) from w...Alexander Decker
The document discusses the application of appopolite, a natural zeolite, for the adsorption of heavy metals cobalt and nickel from wastewater. It examines the effects of parameters like adsorbent amount, pH, temperature, and initial metal ion concentration on the adsorption process. The Langmuir and Freundlich isotherm equations are used to model the adsorption isotherms and the Langmuir equation provided a better fit to the experimental data. Maximum adsorption of cobalt was found at an adsorbent dosage of 5g/l. Adsorption decreased in more acidic media and was inversely proportional to metal concentration.
Application of appopolite in adsorption of heavy metals (co and ni) from wast...Alexander Decker
This document discusses the application of appopolite zeolite for adsorbing heavy metals like cobalt and nickel from wastewater. It examines how factors like contact time, initial metal concentration, adsorbent dosage, and temperature affect adsorption efficiency. The Langmuir and Freundlich adsorption isotherm equations are used to model adsorption, with the Langmuir model providing a better fit to experimental data. Adsorption efficiencies increased with contact time up to 180 minutes, after which equilibrium was reached.
This document discusses the effect of clay in rocks on asphalt performance. It defines clay as particles less than 4 micrometers in diameter, distinguishing it from dust which is particles less than 75 micrometers. Different types of clay minerals form in rocks and can impact asphalt differently, with some being relatively inert and others causing problems when they absorb water, like swelling. The document outlines standard tests for determining the presence of clay minerals and their impact on aggregate and asphalt properties.
Soil is formed by the weathering and disintegration of rock. Key factors that influence soil formation are climate, organisms, topography, parent material and time. Soils are composed mainly of silicates, with quartz being the most abundant mineral. Other common minerals include feldspars, micas and clay minerals like kaolinite, illite and montmorillonite. Laboratory testing of soils helps characterize properties like particle size distribution, moisture content, liquid limit, plastic limit and organic content which inform geotechnical analysis and design.
IRJET- Dispersive Soils-Characterization, Problems and RemediesIRJET Journal
This document discusses dispersive soils, which are soils that easily disperse or break apart when exposed to flowing water. Dispersive soils can cause problems for earth structures and embankments. The document describes various tests that can identify dispersive soils, including the crumb test, double hydrometer test, and pinhole test. It also discusses how the mineralogy and chemistry of soils, particularly the presence of sodium ions, can cause soils to disperse. Remedies for stabilizing dispersive soils include adding amendments to change the soil chemistry.
The document discusses a midterm exam for a soil science class and various topics related to clay mineralogy and soil properties. It includes the following key points:
1. A midterm exam will take place on February 22nd in the usual classroom at 11 AM.
2. It discusses the properties and structures of common clay minerals like smectite, kaolinite, vermiculite, mica, and chlorite.
3. Ion exchange is described as an important process where ions are exchanged between soil particles and plant roots, affecting nutrient availability and other soil properties.
Clay Minerology & Plasticity Characteristics of SoilArbaz Kazi
This presentation describes about various states of soil, plasticity of soil, various clay minerals, consistency limits, structure of clay minerals, classification of clay minerals based on Activity number
The document discusses clay minerals and their interaction with water. It describes how clay minerals are formed from the weathering of rocks by water. The basic units of clay minerals are silica tetrahedra and octahedral sheets. Clay minerals can have 1:1, 2:1, or 2:1:1 layer structures. Clay particles have negative charges due to isomorphic substitution and broken bonds. Polar water molecules form hydrogen bonds with clay surfaces, becoming tightly bound in monolayers.
This document presents information on clay minerals. It begins with an introduction stating that clay minerals are formed through chemical weathering and are found in shales. It then discusses the basic structural units of clay minerals, which are tetrahedral and octahedral sheets. The document outlines different types of bonding in clay minerals and provides a classification of clay minerals including kaolinite, halloysite, montmorillonite and illite. In conclusion, it restates that clay minerals are layer silicates formed by weathering and describes their layered atomic structure and different bonding types.
This case study analyzed clay occurrences around Kutigi Central Bida Basin in Nigeria. Detailed field mapping identified two hills near Kutigi town containing clay deposits. Laboratory analysis of samples from the hills using X-ray diffraction found them to be composed primarily of kaolinite and quartz minerals. Kaolinite alone constituted about 43.64% of the samples, while quartz constituted around 54.55%. This study characterized the geology and mineralogical composition of clays in this region of Nigeria.
This document discusses clay minerals and their identification. It begins by explaining the origin of clay minerals from the weathering of parent rocks by water. The main clay minerals are then described, including their chemical composition, crystal structure, and properties. Kaolinite, illite, montmorillonite and other clay minerals are 1:1, 2:1, and 2:1:1 layer silicates with different bonding and swelling capabilities. Identification methods for clay minerals are also summarized, such as x-ray diffraction to determine crystal spacing, differential thermal analysis to observe temperature reactions, and other techniques.
The chemistry of clay in the drilling industryAnushka112464
The chemistry of clay in the drilling proceedings and the various kinds of clay structures that can be formed and used in the industry. This could for various purposes and take into consideration several factors. The pdf goes through these in good detail. It also contains numericals pertaining to the aforementioned topics. It also provides the reader with the solution. It is well illustrated and contains the necessary graphs.
The chemistry of clay in the drilling proceedings and the various kinds of clay structures that can be formed and used in the industry. This could for various purposes and take into consideration several factors. The pdf goes through these in good detail. It also contains numericals pertaining to the aforementioned topics. It also provides the reader with the solution. It is well illustrated and contains the necessary graphs.
Clay mineralogy involves studying the structure and properties of clay particles at the microscopic and atomic scales. There are three main types of clay minerals - kaolinite, montmorillonite, and illite. All clay minerals have a basic structure consisting of a silica tetrahedral sheet bonded to an aluminum octahedral sheet. Kaolinite has a thickness of 7.2 angstroms while montmorillonite is thicker at 10 angstroms due to water and ions between its layers. Clays have a large surface area and interact strongly with water due to their surface charge and layered structure. Soil structure depends on particle size and arrangement - coarse soils have single grains while clays can be dispersed or flocculated
Clay minerals are hydrous aluminum silicates that form in soils, sediments, and by alteration of rocks. They have a layered structure composed of silicon tetrahedra and aluminum octahedra sheets. The main clay minerals are kaolinite, illite, smectite (including montmorillonite), chlorite, and vermiculite. Kaolinite has a 1:1 layered structure while illite, smectite, and chlorite are 2:1 layered phyllosilicates. Smectite has expandable interlayers that absorb water. Clay minerals are important constituents of soils and sediments and have various industrial uses such as in drilling muds, ceramics, and environmental
The document discusses key properties and composition of soil. It describes how soil properties are determined by geological material, vegetation, weathering over time, topography, and human activities. It focuses on the chemical properties of soil, especially cation exchange capacity (CEC) which is important for soil fertility. CEC is the ability of soil to retain exchangeable cations like calcium, magnesium, potassium and sodium which are important for plant nutrition. Factors that influence CEC include the type and amount of clay minerals and organic matter in the soil.
CLASSIFICATION, STRUCTURE, CHEMICAL COMPOSITION AND PROPERTIES OF CLAY MINERA...BarathKumar163434
Soil clays can exist in crystalline, structurally disordered or amorphous form.
Amorphous : has no recognizable shape or geometrical internal arrangement of atoms
Crystalline: atomic arrangement repeated at regular pattern in 3 dimensional directions
spatial arrangement of atoms producing building unit of a crystal is called the unit cell
By placing several unit cells together, the crystal arrangement produced is then called a lattice structure
unit cells has a volume of approximately 1µm3
packing of silica tetrahedran and aluminum octahedran sheets, forms a layered clay structure
the total assembly of a layer plus interlayer material is called an unit structure
A comparative study on adsorption behavior of heavy metal elements onto soil ...Andre Zeitoun
1) The document examines the adsorption behavior of heavy metal elements from an acid solution onto common soil minerals (illite, halloysite, zeolite, goethite) over various time periods.
2) The results show that the adsorption extent of elements varies depending on the mineral type and reaction time, with Fe and As being significantly removed within an hour.
3) Overall, halloysite was found to be the most effective adsorbent, though adsorption of alkali elements did not follow predictions based on ionic radii.
11.application of appopolite in adsorption of heavy metals (co and ni) from w...Alexander Decker
The document discusses the application of appopolite, a natural zeolite, for the adsorption of heavy metals cobalt and nickel from wastewater. It examines the effects of parameters like adsorbent amount, pH, temperature, and initial metal ion concentration on the adsorption process. The Langmuir and Freundlich isotherm equations are used to model the adsorption isotherms and the Langmuir equation provided a better fit to the experimental data. Maximum adsorption of cobalt was found at an adsorbent dosage of 5g/l. Adsorption decreased in more acidic media and was inversely proportional to metal concentration.
Application of appopolite in adsorption of heavy metals (co and ni) from wast...Alexander Decker
This document discusses the application of appopolite zeolite for adsorbing heavy metals like cobalt and nickel from wastewater. It examines how factors like contact time, initial metal concentration, adsorbent dosage, and temperature affect adsorption efficiency. The Langmuir and Freundlich adsorption isotherm equations are used to model adsorption, with the Langmuir model providing a better fit to experimental data. Adsorption efficiencies increased with contact time up to 180 minutes, after which equilibrium was reached.
This document discusses the effect of clay in rocks on asphalt performance. It defines clay as particles less than 4 micrometers in diameter, distinguishing it from dust which is particles less than 75 micrometers. Different types of clay minerals form in rocks and can impact asphalt differently, with some being relatively inert and others causing problems when they absorb water, like swelling. The document outlines standard tests for determining the presence of clay minerals and their impact on aggregate and asphalt properties.
Soil is formed by the weathering and disintegration of rock. Key factors that influence soil formation are climate, organisms, topography, parent material and time. Soils are composed mainly of silicates, with quartz being the most abundant mineral. Other common minerals include feldspars, micas and clay minerals like kaolinite, illite and montmorillonite. Laboratory testing of soils helps characterize properties like particle size distribution, moisture content, liquid limit, plastic limit and organic content which inform geotechnical analysis and design.
IRJET- Dispersive Soils-Characterization, Problems and RemediesIRJET Journal
This document discusses dispersive soils, which are soils that easily disperse or break apart when exposed to flowing water. Dispersive soils can cause problems for earth structures and embankments. The document describes various tests that can identify dispersive soils, including the crumb test, double hydrometer test, and pinhole test. It also discusses how the mineralogy and chemistry of soils, particularly the presence of sodium ions, can cause soils to disperse. Remedies for stabilizing dispersive soils include adding amendments to change the soil chemistry.
The document discusses a midterm exam for a soil science class and various topics related to clay mineralogy and soil properties. It includes the following key points:
1. A midterm exam will take place on February 22nd in the usual classroom at 11 AM.
2. It discusses the properties and structures of common clay minerals like smectite, kaolinite, vermiculite, mica, and chlorite.
3. Ion exchange is described as an important process where ions are exchanged between soil particles and plant roots, affecting nutrient availability and other soil properties.
Grouting various techniques of grouting.pptxUmarSaba1
Grouting involves injecting a slurry or liquid into soil or rock to fill voids and fractures. There are three main modes of grouting: permeation where grout freely flows into voids, compaction where grout remains intact and exerts pressure, and hydraulic fracturing where grout rapidly penetrates fractured zones. Common grout materials include suspensions of cement and water, emulsions of asphalt and water, and chemical solutions. Important grout properties include viscosity, setting time, strength, stability, and toxicity. Common grouting methods are permeation, compaction, jet, and soil fracture grouting. Grouting is used for applications such as seepage control, soil stabilization, vibration control,
Lateral earth pressure Theories Design of retainingUmarSaba1
Foundations carry and distribute loads from structures to the ground to prevent excessive settlement. There are several foundation types including strip, pad, and raft foundations which can bear directly on the ground or be supported by piles. The choice depends on ground conditions and the structure's layout and loading. Pad footings support single columns while strip footings support load-bearing walls or closely spaced columns. Raft foundations distribute loads over a large area for poor soil conditions. The document provides an example of designing a square pad footing to support a column based on loadings and soil capacity.
Crack width measurement & Cracks In Concrete.pptxUmarSaba1
Cracks in concrete structures can be either structural or non-structural. Structural cracks endanger safety while non-structural cracks are mainly caused by internal stresses and do not impact safety directly. The main causes of non-structural cracks are moisture changes, thermal movement, elastic deformation, creep, chemical reactions, foundation movement, and growth of vegetation. Moisture changes cause concrete and masonry materials to expand when wet and contract when dry. Thermal movement results from the expansion and contraction of materials with temperature changes. Elastic deformation and creep cause slow deformation over time under sustained loads. Chemical reactions can cause expansion and weakening of materials. Foundation settlement and vegetation roots can also apply stresses leading to cracks.
Crack In Concrete & Crack width measurement.pptxUmarSaba1
The document discusses cracks in concrete structures. It begins by classifying cracks as structural or non-structural and further classifying cracks by width. Common causes of cracking are then outlined, including plastic shrinkage, drying shrinkage, thermal stresses, chemical reactions, weathering, poor construction practices, and design errors. Methods for evaluating cracks, selecting repair procedures, and repair methods such as epoxy injection, routing and sealing, reinforcing, and cement grouting are also summarized.
Lateral earth pressure Theories & Design of retaining.pptxUmarSaba1
This document discusses lateral earth pressure theories and design of retaining walls. It defines lateral earth pressure as the force exerted by a soil mass on an earth-retaining structure, such as a retaining wall. The document outlines Rankine's theory of lateral earth pressure, which distinguishes between active pressure when a wall moves away from soil and passive resistance when a wall moves toward soil. It also addresses effects of submergence, surcharge loading, and provides two examples of calculating lateral earth pressures.
The document provides guidelines on academic integrity and preventing plagiarism. It defines plagiarism and lists examples such as copying others' work, copy-pasting from multiple sources, and presenting collaborative work as independent. Punishments for plagiarism include repeating assignments, receiving zero marks, warnings, or dismissal. The document is presented in both English and Arabic.
Immediate and time-dependent losses cause the prestress in tendons to decrease over time. Immediate losses occur when prestress is transferred to the concrete and include elastic shortening, wedge draw-in, friction, and member deformation. These can account for around 10% loss of jacking force. Time-dependent losses gradually reduce prestress further over the life of the structure, through mechanisms like creep, shrinkage, and relaxation. By the end of a structure's design life, total losses may reach around 25% of the initial jacking force. Friction in post-tensioning also causes losses along the length of the tendon.
Lateral earth pressure Theories Design of retaining.pptxUmarSaba1
This document discusses lateral earth pressure theories and design of retaining walls. It defines lateral earth pressure as the force exerted by a soil mass on an earth-retaining structure, such as a retaining wall. The document outlines Rankine's theory of lateral earth pressure, which distinguishes between active pressure when a wall moves away from soil and passive resistance when a wall moves toward soil. It also addresses effects of submergence, surcharge loading, and provides two examples of calculating lateral earth pressures.
Introduction - Design of Structure - 1.pdfUmarSaba1
This document discusses reinforced concrete structures and their design. It covers various reinforced concrete elements like beams, slabs, columns and footings. It describes properties of reinforced concrete and its advantages over plain concrete. It discusses design philosophies and failure modes. It also covers concrete mix design and grades of concrete and steel used in reinforced concrete structures. Reinforcement details for different elements are presented along with their behavior under loads. American Society of Civil Engineers code of ethics for engineers is also mentioned. References from ProQuest and open online resources are provided.
This document summarizes key concepts related to shear stresses and flexural design in prestressed concrete beams.
It discusses how prestressing increases the shear resistance of concrete sections by providing compression. The design ultimate shear resistance is calculated for both uncracked and cracked sections using equations that consider factors like prestressing steel stress and effective depth.
A three-case design procedure is outlined for providing shear reinforcement if needed. The document also covers flexural design basics like assuming a triangular stress distribution, calculating resistance moment using prestressing steel properties and depth parameters, and working through examples to determine moment capacity.
This document discusses the analysis of singly and doubly reinforced concrete beam sections. It begins by defining singly reinforced sections as having tension reinforcement only, while doubly reinforced sections have reinforcement in both tension and compression zones. Design steps are provided for both section types, including calculating loads, moments, reinforcement areas, and shear reinforcement. Formulas and assumptions used in the design process are also outlined. The goal is for students to learn to properly design reinforced concrete beam sections based on given structural loads and material properties.
This document discusses the analysis of singly and doubly reinforced concrete beam sections. It provides definitions and design approaches for singly reinforced, doubly reinforced, and flanged beam sections. The key steps in the design process are outlined, including calculating loads and moments, checking for section type, sizing tension and compression reinforcement, and designing shear reinforcement. Design examples are provided for a singly reinforced and a doubly reinforced concrete beam according to BS 8110 design code standards.
The document provides information on the bisection method and Newton-Raphson method for finding roots of equations. The bisection method involves repeatedly bisecting the interval between two values where the function changes sign to zero in on a root. The Newton-Raphson method estimates successive approximations of a root by taking the tangent line of the function at the current point. An example applies the bisection method to find the depth a floating ball is submerged.
The document discusses procurement planning for World Bank projects. It explains that procurement planning involves identifying procurement needs, deciding on contracting strategies, considering technical and supply factors, packaging of items, and choosing procurement procedures. The planning process also includes developing a procurement schedule that assesses lead times, administrative requirements, and contract performance to determine critical paths. The resulting procurement plan is an important tool that serves as an execution guide for procurement and a basis for reviews and audits.
An In-Depth Exploration of Natural Language Processing: Evolution, Applicatio...DharmaBanothu
Natural language processing (NLP) has
recently garnered significant interest for the
computational representation and analysis of human
language. Its applications span multiple domains such
as machine translation, email spam detection,
information extraction, summarization, healthcare,
and question answering. This paper first delineates
four phases by examining various levels of NLP and
components of Natural Language Generation,
followed by a review of the history and progression of
NLP. Subsequently, we delve into the current state of
the art by presenting diverse NLP applications,
contemporary trends, and challenges. Finally, we
discuss some available datasets, models, and
evaluation metrics in NLP.
Sachpazis_Consolidation Settlement Calculation Program-The Python Code and th...Dr.Costas Sachpazis
Consolidation Settlement Calculation Program-The Python Code
By Professor Dr. Costas Sachpazis, Civil Engineer & Geologist
This program calculates the consolidation settlement for a foundation based on soil layer properties and foundation data. It allows users to input multiple soil layers and foundation characteristics to determine the total settlement.
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expansive soil stabilization-210707171052.pptx
1. Index
1. Introduction to Expansive soil
2. Different mineral content in clay soil
a)TETRAHEDRAL SHEET
b)Octahedral sheet
3. Clay-water interaction
4. Clay particle interaction
5. Identification of expansive soil
6. Treatment of expansive soil
7. Foundation on expansive soil
2. INTRODUCTION
Expansive soil are those soil which
swell considerably on absorption of
water and shrink on removal of
water.
When expansive soil swells cohesion
decreases.
The variation in volume of the soil is
to the extent of 20% to 30% of the
original volume.
In India the expansive soils cover
approximately 20% of the total land
area.
3. Continue……
Expansive soils are very small in size and have a large surface area that attract the free water .
Because of these characteristics expansive soil (clay) exhibits extreme change in volume.
One pound of
montmorillonite
particle would have
An incredible surface
area = 325 ha with
which to attract
water.
4. Different mineral content in clay soil
Expensive soil or clayey soil are made up of different mineral content which is
evolved from chemical weathering.
Clay mineral particles are tiny crystalline substances, very small in size and flaky in
shape.
These particles are microscopic.
The particle size of clay is < 2micron in diameter but all the particles having size <
2micron need not to be a clay particle because the clay particles have electrical
charges on their surface.
5. So let’s discuss clay mineralogy…..
Almost all clay minerals are made up of two fundamental crystal sheets joined
through different bonds.
One is a tetrahedral Sheet which is also called a silica sheet and another one is an
octahedral Sheet also called an Alumina Sheet or Gibbsite Sheet.
6. TETRAHEDRAL SHEET
• A Tetrahedral sheet is made up of several Silica tetrahedral units combined together.
• One Silica Tetrahedral Unit consists of a silicon ion (Si4+) surrounded by four oxygen
ions (O2-) forming a shape of tetrahedron. Silicon sits at the centre and oxygen ions
sit at the tips of tetrahedron.
• Each oxygen is shared with two units of tetrahedron.
• There is a hexagonal opening in the sheet.
7. Continue…
Each oxygen at base is shared
in two units so carry -1 charge.
Oxygen at top has -2 charge.
Silicon ions has +4 .
Therefore net charge on each
unit is –
-1-1-1-2+4=-1
+4
8. Octahedral sheet or Gibbsite Sheet
Made up of Octahedral Units.
One octahedral unit consists of six
hydroxyls forming a configuration of
an octahedron and having one
aluminium ion at the centre.
1 OH is shared by 3 units of
octahedral and each OH has -1
charge.
So net charge due to 6 OH is-
= 6 × (−1) × (
1
3
)
= -2
Charge on Al= +3
So net charge on each unit
= +3-2
= +1
9. Three important clay minerals
1. Kaolinite
Kaolinite mineral is made up of silica
and gibbsite sheets.
In its basic structural unit these are
stacked one over the other and tips of
silica sheets are embedded in the
gibbsite sheet.
The thickness of such structural unit is
about 7 Angstrom.
As this mineral is formed by stacking of
one layer of each sheet it is sometimes
called a 1:1 clay mineral.
Kaolinite mineral is formed by staking
one over the other such several basic
units. This unit extends indefinitely in
other dimensions.
10. Continue….
These structural units join together by hydrogen bond
between hydroxyls of alumina sheet and oxygen of silica
sheet.
As the hydrogen bond is sufficiently strong, the kaolinite
mineral is stable and water cannot easily enter between the
structural units and cause expansion. kaolinite is the least
active of all clay minerals.
11. 2. Montmorillonite
The basic structural unit of
montmorillonite consists of a
gibbsite sheet sandwiched
between two silica sheets to form
a single layer. The thickness of this
layer is about 10 A and clearly it is
a 2:1 mineral.
Montmorillonite mineral is formed
by many such structural units
joined together by Vander Waals
force which is a very weak force
compared to hydrogen bond.
Clay soils that attract more water
have more plasticity, more swelling
or shrinkage.
12. Continue…..
Water molecules are dipolar and negatively charged surface of silica sheet attracts these molecules
in the space between two structural units causing the layers of the mineral to be further separated
which results in the expansion of the mineral.
That is why soils containing clay mineral montmorillonite exhibit high volume change. They swell as
the water enters into the structure and shrink as the water is removed.
In India, clay soils containing montmorillonite mineral are commonly known as black cotton soils. It
covers about country’s 20 % area in the states of Andhra Pradesh, Karnataka, Madhya Pradesh,
Maharashtra and Uttar Pradesh.
13. 3. Illite
Its basic structural unit is similar to that of
montmorillonite, so it is also a 2:1 mineral and layer
thickness is also about 10
In this mineral there is isomorphous substitution of
silicon ions in silica sheet by aluminium ion. Also the
potassium ions occupy the space between different
structural units and do not allow water to take its
place.
Potassium ion bonds the two layers together more
firmly which was not the case in the
montmorillonite. Therefore, illite does not swell as
much in the presence of water as montmorillonite,
but still it does much more than kaolinite.
Soils containing illite swell more than that of soil
containing kaolinite but less than that of soil
containing montmorillonite.
14. Clay-water interaction
Clay particles generally have Negative charges on them except at edge.
Water molecules can attract with clay in the following ways:
+ + +
+ + +
-
-
-
-
-
-
-
-
-
+ -
+ -
+ -
+ -
a) Attraction due to electrostatic forces
k
Cation
- +
- +
b) Attraction through cation attachment
On surface of clay particle
15. Clay particles interaction
1. Flocculated structure:
Flocculated structure is formed when net force
between clay particle is attractive.
This is edge to face interaction.
It has high quantity of voids.
The type of structure has high seepage velocity.
NOTE:
Marine clay have flocculated structure due to
presence of salts.
16. 2. Dispersed structure:
This type of structure is formed when
net force between clay particles is
repulsive.
It has face to face interaction.
Generally, one dimensional seepage
velocity is high.
It has low voids as compared to
flocculated structure.
Note:
Lacustrine soil has dispersed structure.
17. Identification of expansive soil
Identification of expansive soil
Mineralogical
identification
Physical
properties
X ray
diffraction
Differential
thermal analysis
Electron
microscopy
Free swell
test
Differential Free
swell test
Swelling pressure
test
18. Mineralogical identification
1. Differential thermal analysis (DTA) :
The DTA method is based on the fact that certain characteristic reactions take place at specific
temperature for different minerals.
When these minerals heated to high temperatures, resulting in a loss of
or gain in heat.
A specimen of the soil with the unknown mineral is heated continuously along with an inert
substances in a electric oven and a record of change in temperature of the mineral plotted against
oven temperature is obtained.
By comparing this with the available records of several known clay minerals, the type clay mineral
present and its amount can be known.
19. 2. X ray diffraction method
Different minerals with different regular patterns of crystalline structures
will diffract x-ray to yield different x-ray diffraction patterns.
With the x-ray diffraction patterns of common clay minerals being known,
it is possible to know which types of mineral are present and in what
proportion.
3. Electron microscopy
In electron microscopy, the soil is observed under polarized light in an
electron microscope .
The method requires skill and experience.
Certain characteristics stains etc. are indications of the nature of the clay
minerals present.
20. 1. Free swell test
Holts and Gibbs(1956) suggested free swell
test.
10 𝑐𝑚3
of dry soil passing through 425 micron
sieve is poured into a 100 𝑐𝑚3 graduated
cylinder filled with water.
The volume of settled soil is measured after 24
hours.
The free swell % is determined as ,
𝑺𝒇=( 𝐕𝒇-𝐕𝐢)/(𝐕𝒊) × 𝟏𝟎𝟎
Where,
𝑉𝑖= initial dry volume of poured soil (10 𝑐𝑚3
)
Bentonite , a highly swelling soil which contains
montmorillonite may have a free swell value
ranging from 1200 to 2000% , Kaolinite about
80% and illite from 30 to 80%.
Identification based on physical properties
21. Continue…..
The free swell value increases with plasticity index.
• Soils having a free swell value as low as 100% can cause considerable
damage to lightly loaded structures and soils having a free swell value
below 50% seldom exhibit appreciable volume change even light loadings.
22. Two samples of dried soil weighing 10g each, passing through 425 𝜇 sieve are
taken.
One is put in a 50cc graduated glass cylinder containing kerosene oil ( a
nonpolar liquid ). The other sample is put in a similar cylinder containing
distilled water.
Both the samples are left undisturbed for 24 hours and then their volumes
are noted.
The DFS is expressed as,
DFS =
(𝑺𝒐𝒊𝒍 𝒗𝒐𝒍𝒖𝒎𝒆 𝒊𝒏 𝒘𝒂𝒕𝒆𝒓)−(𝑺𝒐𝒊𝒍 𝒗𝒐𝒍𝒖𝒎𝒆 𝒊𝒏 𝒌𝒆𝒓𝒐𝒔𝒆𝒏𝒆)
𝑺𝒐𝒊𝒍 𝒔𝒂𝒎𝒑𝒍𝒆 𝒊𝒏 𝒌𝒆𝒓𝒐𝒔𝒆𝒏𝒆
The degree of expansiveness increases with increasing DFS%.
2. Differential free swell test
23. 3. Swelling pressure test
Swelling pressure can be defined as the maximum force
per unit area required to be placed over a swelling soil to
prevent volume increase.
Swelling is very useful index of the trouble potential of an
expansive soil.
A swelling pressure can be defined from two different
types of tests.
(1). Swell Pressure Test by Consolidometer
(2). Swell Pressure Test by Constant Volume Method
24. 1. Swell Pressure Test by Consolidometer
In this type of test, the specimen is placed in a odometer under a small surcharge of
about 7.0 kN/m2.
Water is added to the specimen allowing it to swell and reach an equilibrium position
after some time.
Now pressure on the specimen is gradually increased and the specimen is allowed to
consolidate.
The plot of specimen deformation (𝛿 ) versus pressure (𝜎′) is drawn
25. 2. Constant volume test
The constant volume test can be conducted by taking a
specimen in a consolidation ring and applying a pressure
equal to the effective overburden pressure, 𝜎0’ plus the
approximate anticipated surcharge caused by the
foundation 𝜎𝑠’.
Water is then added to the specimen. As the specimen
start to swell , pressure is applied in small increments to
prevent swelling.
Pressure is maintained untill full swelling pressure is
developed on the specimen, at that time the total
pressure is ,
𝜎𝑠𝑤′= 𝜎0’ + 𝜎𝑠’+ 𝜎1’
where,
𝜎𝑠𝑤′ = Total pressure applied to prevent swelling
𝜎0’ = effective overburden pressure
𝜎𝑠’ = surcharge caused by foundation
𝜎1’ = additional pressure applied to prevent swelling after
addition of water.
26. Treatment of expansive soil
The swelling of a soil has two injurious effects on a structure founded on it .
One is the reduction in the strength of the soil and second is the movement of the
structure.
The following measures may be taken to reduce the swelling potential of soil and
increases the strength.
1. Replacement of expansive soil:
A simple and easy solution for slabs and footing on expansive soils is to replace
the foundation soil with non-swelling soils.
Experiences indicates that there is no danger of foundation movement if the sub
soil consists of 1.5 m of non- swelling soil underlain by highly expansive soil.
27. 2.Moisture barriers :
Moisture control method are applied around the perimeter of the structure .
Moisture barriers may be vertical or horizontal but, vertical barriers are more
effective.
A vertical trench, about 15 cm wide, 1.5m deep and filled with gravel, lean
concrete or lime-fly ash have been quite effective moisture barrier.
The moisture barrier should be supplemented with adequate drainage system.
28. 3. Soil stabilization
Soil stabilization is a process by
which a soils physical property are
transformed to provide long-term
permanent strength gains.
Stabilization is accomplished by
increasing the shear strength and
the overall bearing capacity of a soil.
Once stabilized, a solid monolith is
formed that decreases the
permeability, which in turn reduces
the shrink/swell potential and
harmful effects of freeze/thaw cycles
Different method are available for
soil stabilization .
29. • Soil-lime Stabilization
Lime stabilization improves the strength, stiffness and
durability of fine grained materials.
In addition, lime is sometimes used to improve the
properties of the fine grained fraction of granular soils. Lime
has been used as a stabilizer for soils in the base courses of
pavement systems, under concrete foundations, on
embankment slopes and canal linings.
Addition of about 5-7% of lime reduces the swelling and
shrinkage characteristic of expansive soil.
• Soil-Cement Stabilization:
• Soil-cement is the reaction product of an intimate mixture of
pulverized soil and measured amounts of Portland cement
and water, compacted to high density.
• As the cement hydrates, the mixture becomes a hard,
durable structural material. Hardened soil-cement has the
capacity to bridge over local weak points in a sub grade.
• When properly made, it does not soften when exposed to
wetting and drying, or freezing and thawing cycles
30. Foundation on expansive soil
It is necessary to note that all parts of building will not equally be affected be the
swelling potential of the soil.
Beneath the center of a building where the soil is protected from sun and rain, the
moisture changes are small and the soil movements are least.
Beneath outside the wall, the moisture changes and soil movements are greater.
Hence, damage to building is greater on the outside walls.
• The following types of foundation are provided in expansive soils.
1. Shallow foundation isolated from swelling soils.
2. Waffle slab
3. Drilled pier foundation
4. Under reamed pile
31. 1. Shallow foundation isolated from swelling soils.
Figure shows a typical typical foundation under a outside wall.
The granular material provided around the foundation mitigates the effects of
expansion of the soils.
32. 2. Waffle slab
In this type of construction , the ribs of hold the structure load.
The waffle voids allow the expansion of soil.
33. 3. Drilled pier foundation
Drilled piers are commonly used to
resist uplift forces caused by the
swelling of soils.
Drilled piers when made with
enlarged base are called belled piers,
and made without an enlarged base
are called straight shaft piers.
The bottom of the shaft should be
placed below the active zone of the
expansive soil.
34. 4. Under reamed piles
The under reamed piles are successfully developed by
C.B.R.I, Roorkee, for serving as foundation for black
cotton soils, filled up ground and other types of soils
having poor bearing capacity.
The principle of this types of foundation is to anchor
the structure at a depth where ground movement due
to seasonal moisture changes is negligible.
The under reamed piles are bored cast in situ concrete
piles having one or more bulbs or under reams in its
lower portion.
The bulbs are formed by under reaming tool.
The length of pile is 3 to 8m.
The dia. Of pile is 0.2 to 0.5m.
The dia. of bulb is 2 to 3 times the dia. of pile.
The spacing of pile vary from 2 to 4m.