This document summarizes in-situ methods for determining soil properties, specifically the vane shear test and pressure meter tests.
The vane shear test directly measures the undrained shear strength of soft clays in the field by inserting a rotating vane and measuring the torque. Pressure meter tests measure the soil's stress-strain response by expanding a membrane probe against the soil and recording the resulting pressures and strains. Self-boring pressure meters can test undisturbed soil by drilling into the ground, while displacement pressure meters push into pre-drilled boreholes. Both provide fundamental soil properties with minimal empirical corrections needed.
This document describes the vane shear test procedure used to determine the undrained shear strength of soft clays. Key details include:
- The test involves inserting vanes into an undisturbed clay specimen and rotating them at a uniform rate until failure to measure the undrained shear strength.
- Calculations are done to determine the shear strength from the torque measurement, using the vane diameter and height.
- The test can also measure soil sensitivity by remolding the soil after the initial test and measuring the reduction in strength.
The document summarizes the standard penetration test (SPT), a common in situ geotechnical testing method. It describes the basic procedure, which involves driving a split spoon sampler into subsurface soils using a hammer, and recording the number of blows required for each increment of penetration. Corrections are made to SPT values to account for overburden pressure and dilatancy. Empirical correlations are presented relating SPT values to properties like density, shear strength, and consistency of cohesionless and cohesive soils. Both advantages like being inexpensive and quick, and limitations like lack of precision are discussed.
The document summarizes information about the cone penetration test (CPT), a method used to determine geotechnical engineering properties of soils. It provides a brief history of the CPT, describing how it has evolved from a mechanical cone in the 1930s to electric cones in the 1960s. It then explains that the CPT involves pushing a cone tip into the ground to continuously measure resistance, and describes the components of the CPT device and how the test is conducted. Finally, it outlines the advantages and disadvantages of the CPT and how the results can be used to evaluate soil types, densities, and shear strengths for foundation design purposes.
1. Plate load tests are conducted to determine the ultimate bearing capacity of soil and settlement under a given load by applying loads to circular or square steel plates embedded in an excavated pit.
2. The test setup involves excavating a pit below the depth of the proposed foundation, placing the test plate with a central hole at the bottom, and applying load using a hydraulic jack while measuring settlement.
3. The results provide the subgrade modulus, ultimate bearing capacity divided by a safety factor to determine the safe bearing capacity, and insight into foundation behavior and allowable settlement for design.
The standard penetration test (SPT) involves driving a split spoon sampler into the ground using a 140 lb hammer dropped 30 inches. The number of blows required to penetrate each 6 inch interval is recorded, and the penetration resistance value N is the sum of the blows over the second and third intervals. This test is commonly used to obtain bearing capacity and estimate soil properties like density and shear strength. It is performed whenever the soil stratum changes and at intervals of no more than 1.5 meters.
This document describes the standard penetration test (SPT), which is commonly used to evaluate the engineering properties of soils in the field. It discusses the equipment used, including the drilling rig, split spoon sampler, drive weight assembly, and cathead. It outlines the procedures for drilling a borehole, driving the sampler, and handling the recovered soil sample. Corrections are applied to account for factors like overburden pressure and dilatancy. SPT N-values can be used to estimate properties like relative density, friction angle, and unconfined compressive strength. The test provides representative samples and index properties but has limitations for some soil types.
Plate load tests are used to determine the ultimate bearing capacity and settlement of soil. The test involves gradually loading a circular or square test plate placed in an excavated pit using a hydraulic jack. Dial gauges measure the settlement under each load increment. A load-settlement curve is generated, allowing engineers to determine the safe bearing capacity based on shear failure or permissible settlement. Results provide insight into foundation design and behavior for the site.
The document discusses shear strength of soils. It defines shear strength as the soil's resistance to shearing stresses and deformation from particle displacement. Shear strength depends on cohesion between particles and frictional resistance, as modeled by the Mohr-Coulomb failure criterion. Laboratory tests like direct shear and triaxial shear tests are used to determine the shear strength parameters (c, φ) that describe a soil's failure envelope.
This document describes the vane shear test procedure used to determine the undrained shear strength of soft clays. Key details include:
- The test involves inserting vanes into an undisturbed clay specimen and rotating them at a uniform rate until failure to measure the undrained shear strength.
- Calculations are done to determine the shear strength from the torque measurement, using the vane diameter and height.
- The test can also measure soil sensitivity by remolding the soil after the initial test and measuring the reduction in strength.
The document summarizes the standard penetration test (SPT), a common in situ geotechnical testing method. It describes the basic procedure, which involves driving a split spoon sampler into subsurface soils using a hammer, and recording the number of blows required for each increment of penetration. Corrections are made to SPT values to account for overburden pressure and dilatancy. Empirical correlations are presented relating SPT values to properties like density, shear strength, and consistency of cohesionless and cohesive soils. Both advantages like being inexpensive and quick, and limitations like lack of precision are discussed.
The document summarizes information about the cone penetration test (CPT), a method used to determine geotechnical engineering properties of soils. It provides a brief history of the CPT, describing how it has evolved from a mechanical cone in the 1930s to electric cones in the 1960s. It then explains that the CPT involves pushing a cone tip into the ground to continuously measure resistance, and describes the components of the CPT device and how the test is conducted. Finally, it outlines the advantages and disadvantages of the CPT and how the results can be used to evaluate soil types, densities, and shear strengths for foundation design purposes.
1. Plate load tests are conducted to determine the ultimate bearing capacity of soil and settlement under a given load by applying loads to circular or square steel plates embedded in an excavated pit.
2. The test setup involves excavating a pit below the depth of the proposed foundation, placing the test plate with a central hole at the bottom, and applying load using a hydraulic jack while measuring settlement.
3. The results provide the subgrade modulus, ultimate bearing capacity divided by a safety factor to determine the safe bearing capacity, and insight into foundation behavior and allowable settlement for design.
The standard penetration test (SPT) involves driving a split spoon sampler into the ground using a 140 lb hammer dropped 30 inches. The number of blows required to penetrate each 6 inch interval is recorded, and the penetration resistance value N is the sum of the blows over the second and third intervals. This test is commonly used to obtain bearing capacity and estimate soil properties like density and shear strength. It is performed whenever the soil stratum changes and at intervals of no more than 1.5 meters.
This document describes the standard penetration test (SPT), which is commonly used to evaluate the engineering properties of soils in the field. It discusses the equipment used, including the drilling rig, split spoon sampler, drive weight assembly, and cathead. It outlines the procedures for drilling a borehole, driving the sampler, and handling the recovered soil sample. Corrections are applied to account for factors like overburden pressure and dilatancy. SPT N-values can be used to estimate properties like relative density, friction angle, and unconfined compressive strength. The test provides representative samples and index properties but has limitations for some soil types.
Plate load tests are used to determine the ultimate bearing capacity and settlement of soil. The test involves gradually loading a circular or square test plate placed in an excavated pit using a hydraulic jack. Dial gauges measure the settlement under each load increment. A load-settlement curve is generated, allowing engineers to determine the safe bearing capacity based on shear failure or permissible settlement. Results provide insight into foundation design and behavior for the site.
The document discusses shear strength of soils. It defines shear strength as the soil's resistance to shearing stresses and deformation from particle displacement. Shear strength depends on cohesion between particles and frictional resistance, as modeled by the Mohr-Coulomb failure criterion. Laboratory tests like direct shear and triaxial shear tests are used to determine the shear strength parameters (c, φ) that describe a soil's failure envelope.
The document describes the oedometer test procedure used to determine soil properties like compression coefficient, consolidation coefficient, permeability, and compressibility. The test involves placing a saturated soil sample in an oedometer apparatus and incrementally increasing the load over time while monitoring settlement. Properties are calculated from the settlement readings using methods like square root of time or log of time.
This document presents information about static cone penetration tests. It discusses the principles and applications of cone penetration testing. The principles section explains that a metal cone is penetrated into the subsurface at a constant rate, and the cone tip resistance, sleeve friction, and friction ratio are recorded to determine soil stratigraphy and properties. The applications section notes that data is used to estimate parameters like undrained shear strength and stress history, and that results can be directly applied to soil profiling and engineering designs.
Bearing capacity of shallow foundations by abhishek sharma ABHISHEK SHARMA
elements you should know about bearing capacity of shallow foundations are included in it. various indian standards are also used. Bearing capacity theories by various researchers are also included. numericals from GATE CE and ESE CE are also included.
Class 6 Shear Strength - Direct Shear Test ( Geotechnical Engineering )Hossam Shafiq I
This document describes the direct shear test procedure used in a geotechnical engineering laboratory class to determine the shear strength parameters of soils. It discusses how the direct shear test is conducted by applying a normal stress and increasing shear stress to a soil sample until failure. Key steps of the test procedure are outlined, and the document explains how shear strength parameters like cohesion (C') and the internal friction angle (f) can be calculated from the test results and plotted on a Mohr-Coulomb failure envelope graph.
1. Load-settlement curves for footings on dense sand or stiff clay show a pronounced peak and failure occurs at very small strains, with sudden sinking or tilting and surface heaving of adjoining soil.
2. For medium sand or clay, failure starts at a localized spot and migrates outward gradually, with large vertical strains and small lateral strains. Failure planes are not clearly defined.
3. Failure zones for footings on slopes do not extend above the horizontal plane through the base, and failure occurs when downward and upward pressures are equal.
This document discusses subsoil exploration, which involves collecting soil data through field and laboratory investigations to assess soil properties at a site. The main objectives are to determine the nature, depth, thickness, and extent of soil strata, as well as groundwater depth and properties. Exploration methods include direct techniques like test pits and borings, and indirect techniques like sounding tests and geophysical methods. Standard penetration tests are commonly used to determine properties of cohesionless soils by counting blows required to penetrate the soil. Corrections are applied to penetration values to account for overburden pressure and sample dilatancy.
This document discusses foundation settlements and provides methods for estimating different types of settlements. It discusses:
- Immediate/elastic settlement which occurs during or right after construction and can be estimated using elastic theory equations.
- Consolidation settlement, which is time-dependent and occurs over months to years as water is squeezed out of clay soils. It includes primary consolidation from excess pore pressure dissipation and secondary compression from soil reorientation.
- Methods for estimating settlement in sandy soils using a strain influence factor approach.
- Equations for calculating primary and secondary consolidation settlement based on soil properties and changes in effective stress over time.
- Relationships between time factor, degree of consolidation, and rate of consolidation
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.
Class 8 Triaxial Test ( Geotechnical Engineering )Hossam Shafiq I
The document summarizes laboratory tests conducted on sand and clay soils, including triaxial compression tests and unconfined compression tests. It describes the test procedures, equipment used, and how to analyze the results to determine soil shear strength parameters. Specifically, it outlines how to conduct a consolidated drained triaxial test on sand under three confining pressures and an unconfined compression test on clay to measure the undrained shear strength. Graphs and calculations of stress, strain, and shear strength are presented.
Soil exploration methods and soil investigation reportAnjana R Menon
Soil exploration involves site investigations through methods like boreholes, test pits, and geophysical tests. This provides critical information on ground conditions like soil type, bearing capacity, and water levels for foundation design of structures. The objectives are to evaluate soil properties, predict issues, ensure safety, and select suitable construction methods. A proper exploration program involves reconnaissance, preliminary, and sometimes detailed investigations using appropriate testing and sampling methods based on the project size and soil variability.
This document discusses the consolidation of soil. It defines important terms like compression, compressibility, and consolidation. It outlines the differences between compaction and consolidation. The importance of consolidation theory is that it provides information on total settlement, time for settlement, and types of settlement. Terzaghi's spring analogy is described to explain the consolidation process. A one-dimensional consolidation test procedure is outlined. Important definitions related to consolidation like compression index, swelling index, and coefficients are provided. The document also discusses normally, under, and over consolidated soils and how to determine preconsolidation pressure. Terzaghi's one-dimensional consolidation theory and solution are presented. Methods to determine degree of consolidation and coefficient of consolidation from laboratory test data are
Geotechnical Engineering-II [Lec #19: General Bearing Capacity Equation]Muhammad Irfan
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 summarizes methods of sub-soil exploration for foundation engineering. It discusses various direct and indirect exploration techniques including pits, trenches, borings, percussion drilling, and electrical resistivity methods. Planning of exploration programs involves determining depth based on structure type and significant depth, as well as lateral spacing of bore holes. The objectives of exploration are to select foundations, determine bearing capacity, and investigate existing structures.
Types of samplers used in soil samplingAna Debbarma
There are two types of soil samples:
1. Disturbed samples - The natural structure of the soil is modified or destroyed during sampling.
2. Undisturbed samples - The natural structure and properties of the soil remain preserved.
Soil sampling devices include open drive samplers, piston samplers, and rotary samplers. Open drive samplers use thin-walled tubes that are pushed into the soil to collect undisturbed samples. Piston samplers also use thin-walled tubes but have a piston inside to prevent excess soil from entering and maintain sample integrity. Rotary samplers have an outer rotating barrel and inner stationary tube to collect annular ring samples.
The standard penetration test is an in-situ method to determine soil properties. It involves driving a split spoon sampler into soil using a 63.5kg hammer dropped from 75cm. The number of blows required for each 15cm of penetration is recorded until 45cm is reached, known as the N-value. Proper drilling, cleaning, and sampling procedures are followed to obtain undisturbed soil samples. Collected data like N-values, soil descriptions and depths are recorded and may require corrections based on overburden pressure or dilatancy. The test provides important geotechnical engineering properties of subsurface soils.
This document discusses soil sampling and exploration. It describes different types of soil samples including disturbed, undisturbed, representative and non-representative samples. It discusses criteria for obtaining undisturbed samples and transporting and preserving samples. Different types of soil samplers are described. Factors related to planning a soil exploration program such as spacing and depth of borings are covered. Components of a soil exploration report are outlined.
The document discusses soil mechanics topics related to consolidation and settlement. It covers three types of settlement (immediate, primary consolidation, and secondary consolidation). It also explains the fundamental concept of consolidation using a piston-spring model and describes how a one-dimensional consolidation test (oedometer test) is conducted in the laboratory to determine soil compressibility.
This document discusses direct shear tests which are used to determine the shear strength of soils. It provides definitions of key terms like shear strength and failure. It explains that shear strength depends on interactions between soil particles and failures occurs when particles slide past each other. It describes the direct shear test procedure which involves applying normal and shear stresses to a soil sample in a shear box to cause failure. The document provides equations to calculate normal stress, shear stress, dry unit weight and void ratio from direct shear test data.
The document discusses types of soil sampling methods and procedures. It describes disturbed and undisturbed soil samples, and the different types of samplers used to collect each including split spoon, scraper bucket, Shelby tube, and piston samplers. It also outlines information obtained from soil sampling like soil types, depth to groundwater, and permeability, and details that should be included in the boring and sampling record.
The Standard Penetration Test (SPT) involves driving a thick-walled sampler into the ground using blows from a hammer. The number of blows required for each 150mm of penetration is recorded. Higher blow counts indicate denser soil. SPT results provide an indication of soil strength properties and relative density, especially in granular soils where undisturbed samples are difficult to obtain. However, SPT results have limitations as the test can disturb soils and the blow count data has low resolution. Correlations are used to interpret SPT results but depend on soil type.
The document describes the oedometer test procedure used to determine soil properties like compression coefficient, consolidation coefficient, permeability, and compressibility. The test involves placing a saturated soil sample in an oedometer apparatus and incrementally increasing the load over time while monitoring settlement. Properties are calculated from the settlement readings using methods like square root of time or log of time.
This document presents information about static cone penetration tests. It discusses the principles and applications of cone penetration testing. The principles section explains that a metal cone is penetrated into the subsurface at a constant rate, and the cone tip resistance, sleeve friction, and friction ratio are recorded to determine soil stratigraphy and properties. The applications section notes that data is used to estimate parameters like undrained shear strength and stress history, and that results can be directly applied to soil profiling and engineering designs.
Bearing capacity of shallow foundations by abhishek sharma ABHISHEK SHARMA
elements you should know about bearing capacity of shallow foundations are included in it. various indian standards are also used. Bearing capacity theories by various researchers are also included. numericals from GATE CE and ESE CE are also included.
Class 6 Shear Strength - Direct Shear Test ( Geotechnical Engineering )Hossam Shafiq I
This document describes the direct shear test procedure used in a geotechnical engineering laboratory class to determine the shear strength parameters of soils. It discusses how the direct shear test is conducted by applying a normal stress and increasing shear stress to a soil sample until failure. Key steps of the test procedure are outlined, and the document explains how shear strength parameters like cohesion (C') and the internal friction angle (f) can be calculated from the test results and plotted on a Mohr-Coulomb failure envelope graph.
1. Load-settlement curves for footings on dense sand or stiff clay show a pronounced peak and failure occurs at very small strains, with sudden sinking or tilting and surface heaving of adjoining soil.
2. For medium sand or clay, failure starts at a localized spot and migrates outward gradually, with large vertical strains and small lateral strains. Failure planes are not clearly defined.
3. Failure zones for footings on slopes do not extend above the horizontal plane through the base, and failure occurs when downward and upward pressures are equal.
This document discusses subsoil exploration, which involves collecting soil data through field and laboratory investigations to assess soil properties at a site. The main objectives are to determine the nature, depth, thickness, and extent of soil strata, as well as groundwater depth and properties. Exploration methods include direct techniques like test pits and borings, and indirect techniques like sounding tests and geophysical methods. Standard penetration tests are commonly used to determine properties of cohesionless soils by counting blows required to penetrate the soil. Corrections are applied to penetration values to account for overburden pressure and sample dilatancy.
This document discusses foundation settlements and provides methods for estimating different types of settlements. It discusses:
- Immediate/elastic settlement which occurs during or right after construction and can be estimated using elastic theory equations.
- Consolidation settlement, which is time-dependent and occurs over months to years as water is squeezed out of clay soils. It includes primary consolidation from excess pore pressure dissipation and secondary compression from soil reorientation.
- Methods for estimating settlement in sandy soils using a strain influence factor approach.
- Equations for calculating primary and secondary consolidation settlement based on soil properties and changes in effective stress over time.
- Relationships between time factor, degree of consolidation, and rate of consolidation
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.
Class 8 Triaxial Test ( Geotechnical Engineering )Hossam Shafiq I
The document summarizes laboratory tests conducted on sand and clay soils, including triaxial compression tests and unconfined compression tests. It describes the test procedures, equipment used, and how to analyze the results to determine soil shear strength parameters. Specifically, it outlines how to conduct a consolidated drained triaxial test on sand under three confining pressures and an unconfined compression test on clay to measure the undrained shear strength. Graphs and calculations of stress, strain, and shear strength are presented.
Soil exploration methods and soil investigation reportAnjana R Menon
Soil exploration involves site investigations through methods like boreholes, test pits, and geophysical tests. This provides critical information on ground conditions like soil type, bearing capacity, and water levels for foundation design of structures. The objectives are to evaluate soil properties, predict issues, ensure safety, and select suitable construction methods. A proper exploration program involves reconnaissance, preliminary, and sometimes detailed investigations using appropriate testing and sampling methods based on the project size and soil variability.
This document discusses the consolidation of soil. It defines important terms like compression, compressibility, and consolidation. It outlines the differences between compaction and consolidation. The importance of consolidation theory is that it provides information on total settlement, time for settlement, and types of settlement. Terzaghi's spring analogy is described to explain the consolidation process. A one-dimensional consolidation test procedure is outlined. Important definitions related to consolidation like compression index, swelling index, and coefficients are provided. The document also discusses normally, under, and over consolidated soils and how to determine preconsolidation pressure. Terzaghi's one-dimensional consolidation theory and solution are presented. Methods to determine degree of consolidation and coefficient of consolidation from laboratory test data are
Geotechnical Engineering-II [Lec #19: General Bearing Capacity Equation]Muhammad Irfan
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 summarizes methods of sub-soil exploration for foundation engineering. It discusses various direct and indirect exploration techniques including pits, trenches, borings, percussion drilling, and electrical resistivity methods. Planning of exploration programs involves determining depth based on structure type and significant depth, as well as lateral spacing of bore holes. The objectives of exploration are to select foundations, determine bearing capacity, and investigate existing structures.
Types of samplers used in soil samplingAna Debbarma
There are two types of soil samples:
1. Disturbed samples - The natural structure of the soil is modified or destroyed during sampling.
2. Undisturbed samples - The natural structure and properties of the soil remain preserved.
Soil sampling devices include open drive samplers, piston samplers, and rotary samplers. Open drive samplers use thin-walled tubes that are pushed into the soil to collect undisturbed samples. Piston samplers also use thin-walled tubes but have a piston inside to prevent excess soil from entering and maintain sample integrity. Rotary samplers have an outer rotating barrel and inner stationary tube to collect annular ring samples.
The standard penetration test is an in-situ method to determine soil properties. It involves driving a split spoon sampler into soil using a 63.5kg hammer dropped from 75cm. The number of blows required for each 15cm of penetration is recorded until 45cm is reached, known as the N-value. Proper drilling, cleaning, and sampling procedures are followed to obtain undisturbed soil samples. Collected data like N-values, soil descriptions and depths are recorded and may require corrections based on overburden pressure or dilatancy. The test provides important geotechnical engineering properties of subsurface soils.
This document discusses soil sampling and exploration. It describes different types of soil samples including disturbed, undisturbed, representative and non-representative samples. It discusses criteria for obtaining undisturbed samples and transporting and preserving samples. Different types of soil samplers are described. Factors related to planning a soil exploration program such as spacing and depth of borings are covered. Components of a soil exploration report are outlined.
The document discusses soil mechanics topics related to consolidation and settlement. It covers three types of settlement (immediate, primary consolidation, and secondary consolidation). It also explains the fundamental concept of consolidation using a piston-spring model and describes how a one-dimensional consolidation test (oedometer test) is conducted in the laboratory to determine soil compressibility.
This document discusses direct shear tests which are used to determine the shear strength of soils. It provides definitions of key terms like shear strength and failure. It explains that shear strength depends on interactions between soil particles and failures occurs when particles slide past each other. It describes the direct shear test procedure which involves applying normal and shear stresses to a soil sample in a shear box to cause failure. The document provides equations to calculate normal stress, shear stress, dry unit weight and void ratio from direct shear test data.
The document discusses types of soil sampling methods and procedures. It describes disturbed and undisturbed soil samples, and the different types of samplers used to collect each including split spoon, scraper bucket, Shelby tube, and piston samplers. It also outlines information obtained from soil sampling like soil types, depth to groundwater, and permeability, and details that should be included in the boring and sampling record.
The Standard Penetration Test (SPT) involves driving a thick-walled sampler into the ground using blows from a hammer. The number of blows required for each 150mm of penetration is recorded. Higher blow counts indicate denser soil. SPT results provide an indication of soil strength properties and relative density, especially in granular soils where undisturbed samples are difficult to obtain. However, SPT results have limitations as the test can disturb soils and the blow count data has low resolution. Correlations are used to interpret SPT results but depend on soil type.
FIELD TEST FOR BEARING CAPACITY-revised for BC.pptxsbarai0802
This document discusses various field tests used to determine bearing capacity of soils, including the standard penetration test (SPT), plate load test, cone penetration test (CPT), and pressure meter test. The SPT involves driving a split spoon sampler into the ground using a hammer and measuring the blow counts, while corrections are applied to the observed value. The plate load test applies incremental loads to a steel plate in a pit until a maximum settlement is reached to determine ultimate bearing capacity. The CPT provides continuous measurements of cone resistance with depth to assess soil properties. The pressure meter test measures volume changes in a probe under increasing gas pressure to identify elastic and plastic soil behavior.
The document describes the engineering properties of soil through direct shear tests and triaxial shear tests. Direct shear tests are used to determine the shear strength of soils, especially cohesionless soils, by measuring the cohesion and angle of internal friction. Triaxial shear tests subject a soil sample to three principal stresses and can be conducted under unconsolidated-undrained, consolidated-undrained, or consolidated-drained conditions to evaluate shear resistance. Both tests provide important parameters for geotechnical designs involving soil strengths.
DETERMINATION OF UNCONFINED COMPRESSIVE STRENGTH OF SOILJaptyesh Singh
DETERMINATION OF UNCONFINED COMPRESSIVE STRENGTH OF SOIL in Foundation Engineering
INTRODUCTION
TERMINOLOGY
APPARATUS
SOIL SPECIMEN & ITS TYPES
THEORY
RELEVANCE OF THE EXPERIMENT
PROCEDURE
VIDEO
OBSERVATION
DISCUSSION
REMARKS
This document discusses different types of in-situ soil tests used for subsurface exploration, including penetrometer tests. It describes the standard penetration test (SPT), which involves driving a split-spoon sampler into the soil using blows from a hammer. It also discusses the static cone penetration test (SCPT) and dynamic cone penetration test (DCPT), which measure soil resistance during penetration. SPT values are corrected based on overburden pressure and dilatancy. DCPT can identify soil variability but is not suitable for cohesive soils or depths with rod friction. SCPT and DCPT provide continuous resistance profiles without boreholes.
This presentation describes 6 methods to check concrete sample by performing non destructive testing.
1. Rebound hammer
2. Dye penetration test
3. Pull out test for concrete
4.Half cell potentiometer test
5.Rebar scanner
6 ultrasonic pulse velocity test
This document discusses soil exploration methods, including the purpose of soil exploration to determine foundation type and bearing capacity. It describes various investigation methods like probing, geophysical testing, soil borings using augers or wash boring, and sampling techniques to obtain disturbed and undisturbed soil samples. It also discusses determining boring depth and spacing. Methods to evaluate groundwater conditions and field strength tests like the standard penetration test are summarized.
This document provides information on three common penetration tests: Standard Penetration Test (SPT), Static Cone Penetration Test (SCPT), and Dynamic Cone Penetration Test (DCPT). It describes the procedures, equipment, corrections, and correlations with engineering properties for each test. The SPT is the most commonly used test and provides data on density and strength. The SCPT gives continuous resistance measurements with depth. The DCPT is fast and inexpensive but resistance values must be correlated to SPT results. Each test has advantages and limitations depending on the soil type and project needs.
The document discusses various methods for measuring pressure, including diaphragms, bourdon tubes, capsules, and different transduction methods like potentiometric, strain gauge, variable reluctance, LVDT, variable capacitance, and piezoelectric devices. It also covers topics like pressure multiplexers, calibration using dead weight testers, and force balance transducers using feedback principles. Piezoelectric transducers use materials that generate voltage under mechanical stress, with quartz and ceramics being common choices.
This experiment aims to determine the undrained shear strength of remolded cohesive soil using a vane shear test. The vane shear test involves pushing a four-bladed vane into a soil sample and rotating it until shear failure occurs along a cylindrical surface. The torque required to cause failure is measured and converted to a unit shear resistance. This test is suitable for soft soils where other shear tests may not work accurately, and it can be used to find both the undisturbed and remolded shear strengths to estimate soil sensitivity. The procedure involves filling a container with soil at a set density and water content, inserting the vane, and rotating it until failure while recording the applied torque and calculated shear strength.
UNIT- 4 Traffic English Engineering (1).pptxvigneshk7697
Traffic and Transportation Engineering and management in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party eppudu em kadu le kundaa choodaalni aayana koraru I will add them in a plane frames for wall clock with alarm for men stylish party
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 discusses site investigation methods for assessing soil conditions, which include topographic surveys, soil exploration techniques like test pits and boreholes, in-situ tests, and collecting representative soil samples. The goal of the investigation is to determine soil properties and stratigraphy, groundwater conditions, and suitability of the site for construction in order to inform design and construction and address potential problems. The extent and methods used depend on factors like site conditions, project nature, time and budget available for the investigation.
1. Site Investgation.pptxDebre Markos University Technology College Departmen...teseraaddis1
Soil Exploration
“ The process of exploring to characterize or define small scale properties of substrata at construction sites is unique to geotechnical engineering.
In other engineering disciplines, material properties are specified during design, or before construction or manufacture, and then controlled to meet the specification. Unfortunately, subsurface properties cannot be specified; they must be deduced through exploration.” Charles H. Dowding (1979).
The document summarizes various methods used to analyze soil properties for highway construction projects. It describes procedures for sieve analysis, liquid limit testing, plastic limit testing, and other methods to determine characteristics like density, bearing capacity, and moisture content that are used in designing roadway foundations and pavements. Preliminary soil surveys are also outlined to identify soil types and conditions along proposed routes to inform design and construction decisions.
This document provides information about fluids and cementing for third year bachelor's degree students. It introduces cementing operations for wells, including primary and remedial cementing. It discusses why cementing is important for zonal isolation and casing support. The document outlines the steps for well preparation before cementing, including cleaning the hole, running and centering the casing column. It describes the various equipment used in cementing like float shoes, float collars, scratchers, wiper plugs, and cement heads. The document also covers laboratory tests on cement slurries and the process for primary cementing of conductor pipes and surface casing.
Data Communication and Computer Networks Management System Project Report.pdfKamal Acharya
Networking is a telecommunications network that allows computers to exchange data. In
computer networks, networked computing devices pass data to each other along data
connections. Data is transferred in the form of packets. The connections between nodes are
established using either cable media or wireless media.
Online train ticket booking system project.pdfKamal Acharya
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Sri Guru Hargobind Ji (19 June 1595 - 3 March 1644) is revered as the Sixth Nanak.
• On 25 May 1606 Guru Arjan nominated his son Sri Hargobind Ji as his successor. Shortly
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3. Introduction
• In contrast with other methods Vane Shear Test VST, attempts to measure
undrained shear strength directly.
• Can be conducted in the laboratory as well as in the field
• A selection of vanes available in terms of size, shape, and configuration,
depending upon the consistency and strength characteristics of the soil.
4.
5.
6.
7. AIM
• To determine the undrained shear strength of the clay
Theory
• It is cheaper and quick methods of measuring the shear strength of soft
clay
• Can be conducted in the laboratory as well as in the field
The principle is that an applied torque is resisted by a uniformly distributed
shear stress per unit area acting around the curved surface of a cylinder of
soil.
8. SIGINIFICANCE
• It is suitable for the measurement of shear strength of cohesive soils ,
when soil is of low shear strength(less than 0.5kg/cm^2) for which
triaxial or unconfined tests cannot be performed
• The test gives undrained strength of the soil
• The results obtained from undisturbed and remoulded soils are useful
for evaluating the sensitivity of soil.
9. APPARATUS
1)Vane shear apparatus
• Consist of a steel rod placed vertically and four stainless steel blades placed orthogonally,
which are called vanes
• Arrangement for rotating the vane steadily at a rate of
approx 1/60 rev/min(0.1 degree /s) is provided(length of rod =60mm,d=2.5mm)
• A torque measuring arrangement such as calibrated torsion spring is also attached
2) Specimen container
• 3 nos having dimensions of at least 37.5mm dia and 75mm length(L/D ratio 2 or 3)
10.
11. Procedure
• Clean specimen and fill it with remoulded soil
• Mount the specimen container with vane shear apparatus
• Gently lower the vanes into the specimen ,note the reading of the angle of
twist
• Rotate the vanes at a uniform rate
• Note the final angle of twist repeat the procedure
The difference btw initial and final readings will gives the angle of torque
14. IN-SITU METHOD
• The vane shear test (VST), or field vane (FV), is used to evaluate the inplace
undrained shear strength (suv) of soft to stiff clays & silts at regular depth intervals
of 1meter (3.28 feet).
• The test consists of inserting a four-bladed vane into the clay and rotating the
device about a vertical axis,
• The standard vane has a rectangular geometry with a blade diameter D = 65 mm,
height H = 130 mm (H/D =2), and blade thickness e = 2 mm.
15. Procedure
• The test is best performed when the vane is pushed beneath the bottom
of an pre-drilled borehole.
• For aborehole of diameter B, the top of the vane should pushed to a
depth of insertion of at least df= 4B.
• Within 5 minutes after insertion, rotation should be made at a constant
rate of 6°/minute (0.1°/s) with measurements of torque taken frequently.
16.
17.
18.
19. • The conventional interpretation for obtaining the undrained shear strength from the
recorded maximum torque (T) assumes a uniform distribution of shear stresses both
top and bottom along the blades and a vane with height-to-width ratio H/D = 2
Undrained Strength and
Sensitivity
• The test is normally reserved for soft to stiff materials with suv < 200 kPa. (2
tsf:
20. • After the peak s,, is obtained, the vane is rotated quickly through
10 complete revolutions and the remolded (or "residual") value
is recorded. The in-situ sensitivity of the soil is defined by
• St =Su(Peak)/su(Remould)
21.
22. ADVANTAGES of VST
• Assessment of undrained strength (Suv)
• Simple test and equipment
• Measure in-situ clay sensitivity (St)
• Long history of use in practice
23. DISADVANTAGES of VST
• Limited application to soft to stiff clays
• Slow and time-consuming
• Raw (Suv) needs (empirical ) correction
• Can be affected by sand lenses and seams
25. • Pressuremeter tests can be carried out both in soils and in rocks.
• The aim of a Pressuremeter test is to obtain information on the
stiffness, and in weaker materials on the strength of the ground, by
measuring the relationship between radial applied pressure and the
resulting deformation
26.
27.
28. The Borehole Pressuremeter:
The instrument is inserted into a performed hole.
The pressuremeter has a slightly smaller outside diameter than the diameter of the hole, and
can therefore be lowered to the test position before being inflated.
The radial expansion of the probe when pressurized is inferred from measurements of
volume made at the ground surface using the control/measuring unit.
29.
30. Test methods for Bore-hole pressuremeters:
• Borehole pressure meter consists of two main elements;
a radially-expanding cylindrical probe which is suspended inside the borehole at the
required test level, and a monitoring unit (known as pressure-volumeter) which is
deployed at ground level.
the probe consists of three cells. The outer two cells are known as ̳guard cells‘ and
are normally filled with pressurized gas.
• The central measuring cell is filled with water and is connected to a sight tube
which records volume change in the pressure-volumeter.
• Pressure is provided by means of a CO2bottle.
• Resulting changes in measuring-cell volume are recorded at 15 s, 30s, 60s and
120 s after each pressure increment is applied.
31. The self-boring Pressuremeter:
The instrument is self-bored into the ground with the purpose of
minimizing the soil disturbance caused by insertion.
A self-boring pressuremeter incorporates an internal cutting mechanism at
its base
Factors affecting the amount of disturbance caused by insertion are:
• Soil type
• Distance of the cutter back from the lower edge of the cutting shoe
• Diameter of cutting shoe relative to the un-inflated outside diameter of
the pressure meter membrane;
• The downward force applied during drilling
• The amount of vibration during drilling.
33. Test methods for Self-boring pressuremeter test
Drilling
• A cutter at the foot of the instrument rotates inside an internally tapered shoe.
• As the instrument is pressed steadily against the bottom of the hole, a plug of soil
is extruded into the taper.
• The top of this plug of soil is sliced off by the cutter positioned inside the shoe such that
the pressure needed to drive the soil up the taper is made equal to the in-situ vertical
stress.
• The soil cuttings resulting are carried away up the inside of the instrument by a flow of
flushing fluid, normally water, supplied from the surface.
34.
35. Procedure:
• The testis carried out by applying gas pressure to the inside of this
sleeve and measuring the resulting changes in radius of the elastic
sleeve as a cavity is formed in the soil.
• The pressure at which the sleeve lifts from the rigid body of the
instrument gives the in-situ total stress.
• Two pressure cells mounted through and moving with the
sleeve as it expands, give continuous readings of the pore water
pressureThus, the stress-strain response of the soil can be
obtained
36. Readings:
• All the measurements made by the instruments are transmitted to the
surface by a protected cable passing up inside the gas supply line.
• After application of corrections, self-boring pressuremeter test results are
plotted as a curve of corrected pressure (p) as a function of cavity strain (εc).
Cavity strain is the radial strain of the cavity
Where d0= original diameter of the pressuremeter just before the start of
inflation, under (ideally) the in situ horizontal total stress, and d = current
diameter of the cavity, after expansion under pressure p.Self-boring
pressuremeter results are plotted as applied pressure as a function of cavity strain.
37. Displacement Pressuremeter:
• The instrument is pushed into the ground from the base of a
borehole.
• The soil displaced by the probe during insertion enters the body
of instrument, reducing the disturbance to the surrounding.
38. Advantages of Pressure testing:
For the Self-boring pressure meter
1. The tests are performed on virtually undisturbed soil.
2. A large number of fundamental soil properties are obtained from a
single test.
3. To derive these properties, no empirical correcting factors whatever
are needed.
4. The test is controlled by a semi-automatic system and is
largely independent of operator influence.
5. Results can be obtained quickly.
6. Commercial operation has shown that the instruments, though
more complex than conventional site investigation equipment, are
reliable and have enough redundancy to permit useful readings even
if a single fault appears
39. Disadvantages of Pressuretesting:
1. The instrument will not penetrate gravels, clay stones or the like.
2. Operating in sands usually demands a cased borehole to a level one or
two metres above the desired test locations.
3. Failure planes and deformation modes are not usually appropriate to those
occurring in the final design
4. In practice, only two stress paths can be followed-undrained and fully drained.
5. Undrained tests must usually be performed at high rates of strain so as
to prevent introducing errors
6. The instruments and their associated equipment are complex by
conventional site investigation standards.
7. Results obtained are ,sometimes surprising and in several cases have
challenged conventional assumptions of soil mechanics
40. References
• Soil properties through laboratory observations _ Dr . K.S.Beena ,CUSAT
• Site charaterization and instrumentation_Dr. P.Anbazhagan , IISC BANGALORE
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