This paper presents an experimental investigation on the lateral load capacity of model piles embedded in layered soil. Tests were conducted with piles in loose sand between dense sand and vice versa. The ultimate capacity was estimated using different criteria. The capacity decreased with increased load eccentricity and increased with pile flexural stiffness. The variation of a coefficient representing soil resistance decreased with increased load but increased with flexural stiffness. Experimental data produced load-deflection curves used to evaluate existing models for pile-soil interaction under lateral loads.
This document analyzes the behavior of piles under lateral loading due to soil-structure interaction. It uses the subgrade reaction method to model the soil as a series of elastic springs and analyze the pile as a flexible beam on an elastic foundation. The method is used to calculate the pile deflection, slope, bending moment, and shear force along its length due to a lateral load. These results are validated using finite element modeling in ANSYS software. The document presents an example problem and shows the results from both the subgrade reaction method and ANSYS match well.
This document presents a case study on estimating the modulus of subgrade reaction (k-value) for designing raft foundations of multi-story buildings constructed on sandy soil in Dammam, Saudi Arabia. Site investigations including boreholes and plate load tests were conducted. Plate load tests were back analyzed using numerical modeling to validate the soil properties. Different sized foundations were then modeled to estimate k-values. The k-values decreased with increasing foundation size and sometimes differed from values estimated using Terzaghi's equation, highlighting that k-value depends on foundation properties and soil conditions.
This document discusses the Hoek-Brown failure criterion for estimating the strength and deformation properties of rock masses. It provides details on:
1) Estimating the intact rock strength (ciσ) and Hoek-Brown constant (mi) from triaxial test data on rock cores.
2) Methods for estimating ciσ and mi when direct testing is not possible.
3) Factors that influence rock mass strength estimates such as rock type, discontinuity spacing, and scale of the structure being analyzed.
An Approximate Analysis Procedure for Piled Raft subjected to Vertical Loadingijsrd.com
Piled raft is a geotechnical composite construction consisting of three elements raft, piles and soil. Addition of piles in raft strategically improves ultimate load carrying capacity, decreases overall and differential settlement .The design of piled raft is complicated due to complex interaction between rafts, pile and soil. In recent years due to advent of multistory buildings there has been a significant rise in usage of piled raft in India. This paper presents a simplified method for analysis of piled raft with use of software SAFE considering all the interactions. In the scope of this paper, the design procedure for piled rafts is discussed and results are verified with that available from literature.
The document discusses rock mass properties and the Hoek-Brown failure criterion for estimating the strength of jointed rock masses. It presents the generalized Hoek-Brown criterion equation and describes how to determine the intact rock properties of uniaxial compressive strength (σci) and the Hoek-Brown constant (mi) from triaxial test data or estimates. It also discusses estimating the Geological Strength Index (GSI) of the rock mass.
The document discusses developing a safety concept for combined piled-raft foundations, which act as a composite structure consisting of piles, slab, and subsoil. It proposes using a global safety factor approach and reliability index to define acceptable load and resistance values. Future work is needed to establish design standards through additional research involving measurements, model tests, and numerical simulations.
10 simple mathematical approach for granular fill Ahmed Ebid
This document presents a proposed mathematical approach to simulate ground deformation and soil parameter improvement from dynamic compaction. The approach uses two equations: 1) calculates ground settlement from a single tamper drop based on soil properties and compaction energy. 2) Calculates updated soil parameters based on settlement from the previous drop, allowing simulation of the compaction process. The approach is applied to four case studies and shows close agreement with measured results. It provides a simple way to design and test dynamic compaction procedures and monitor quality by comparing measured and calculated settlements.
Behavior of square footing resting on reinforced sand subjected to incrementa...eSAT Publishing House
This document presents the results of laboratory tests on square footings supported on geogrid-reinforced sand beds. The tests investigated the behavior of footings under incremental loading and unloading conditions for different sand densities and geogrid depth ratios (U/B). Key findings include:
1) Bearing capacity and dynamic soil properties like Cu, Cτ, Cφ, and Cψ increased with higher sand density and U/B up to 0.4.
2) Reinforced sand beds performed better than unreinforced beds, with maximum strength at a U/B of 0.4.
3) Higher sand density led to better footing performance by increasing frictional resistance at the geogrid-
This document analyzes the behavior of piles under lateral loading due to soil-structure interaction. It uses the subgrade reaction method to model the soil as a series of elastic springs and analyze the pile as a flexible beam on an elastic foundation. The method is used to calculate the pile deflection, slope, bending moment, and shear force along its length due to a lateral load. These results are validated using finite element modeling in ANSYS software. The document presents an example problem and shows the results from both the subgrade reaction method and ANSYS match well.
This document presents a case study on estimating the modulus of subgrade reaction (k-value) for designing raft foundations of multi-story buildings constructed on sandy soil in Dammam, Saudi Arabia. Site investigations including boreholes and plate load tests were conducted. Plate load tests were back analyzed using numerical modeling to validate the soil properties. Different sized foundations were then modeled to estimate k-values. The k-values decreased with increasing foundation size and sometimes differed from values estimated using Terzaghi's equation, highlighting that k-value depends on foundation properties and soil conditions.
This document discusses the Hoek-Brown failure criterion for estimating the strength and deformation properties of rock masses. It provides details on:
1) Estimating the intact rock strength (ciσ) and Hoek-Brown constant (mi) from triaxial test data on rock cores.
2) Methods for estimating ciσ and mi when direct testing is not possible.
3) Factors that influence rock mass strength estimates such as rock type, discontinuity spacing, and scale of the structure being analyzed.
An Approximate Analysis Procedure for Piled Raft subjected to Vertical Loadingijsrd.com
Piled raft is a geotechnical composite construction consisting of three elements raft, piles and soil. Addition of piles in raft strategically improves ultimate load carrying capacity, decreases overall and differential settlement .The design of piled raft is complicated due to complex interaction between rafts, pile and soil. In recent years due to advent of multistory buildings there has been a significant rise in usage of piled raft in India. This paper presents a simplified method for analysis of piled raft with use of software SAFE considering all the interactions. In the scope of this paper, the design procedure for piled rafts is discussed and results are verified with that available from literature.
The document discusses rock mass properties and the Hoek-Brown failure criterion for estimating the strength of jointed rock masses. It presents the generalized Hoek-Brown criterion equation and describes how to determine the intact rock properties of uniaxial compressive strength (σci) and the Hoek-Brown constant (mi) from triaxial test data or estimates. It also discusses estimating the Geological Strength Index (GSI) of the rock mass.
The document discusses developing a safety concept for combined piled-raft foundations, which act as a composite structure consisting of piles, slab, and subsoil. It proposes using a global safety factor approach and reliability index to define acceptable load and resistance values. Future work is needed to establish design standards through additional research involving measurements, model tests, and numerical simulations.
10 simple mathematical approach for granular fill Ahmed Ebid
This document presents a proposed mathematical approach to simulate ground deformation and soil parameter improvement from dynamic compaction. The approach uses two equations: 1) calculates ground settlement from a single tamper drop based on soil properties and compaction energy. 2) Calculates updated soil parameters based on settlement from the previous drop, allowing simulation of the compaction process. The approach is applied to four case studies and shows close agreement with measured results. It provides a simple way to design and test dynamic compaction procedures and monitor quality by comparing measured and calculated settlements.
Behavior of square footing resting on reinforced sand subjected to incrementa...eSAT Publishing House
This document presents the results of laboratory tests on square footings supported on geogrid-reinforced sand beds. The tests investigated the behavior of footings under incremental loading and unloading conditions for different sand densities and geogrid depth ratios (U/B). Key findings include:
1) Bearing capacity and dynamic soil properties like Cu, Cτ, Cφ, and Cψ increased with higher sand density and U/B up to 0.4.
2) Reinforced sand beds performed better than unreinforced beds, with maximum strength at a U/B of 0.4.
3) Higher sand density led to better footing performance by increasing frictional resistance at the geogrid-
This document discusses a study on the influence of interference between symmetrical footings on the bearing capacity of soil. The study involved plate load tests on square, circular and rectangular footings placed with varying spacing (15 cm and 20 cm) on sand. The results showed that:
1) The ultimate bearing capacity of footings increased as the spacing between them decreased, with capacities up to 20% higher than isolated footings.
2) The efficiency factor, which represents the ratio of bearing capacity of interfering footings to isolated footings, ranged from 0.7 to 1.2 and decreased with increased spacing.
3) Settlement of footings generally remained the same or increased compared to isolated footings, and increased
This document provides an overview of soils investigation and foundation design. It discusses the importance of soils investigation to evaluate subsurface conditions for construction projects. Various field and laboratory techniques are described for soils investigation, including test pits, boreholes, geophysical methods, and laboratory analysis. Factors influencing soil formation such as weathering and transportation are also covered. The document then discusses shallow foundation design, including bearing capacity theory, settlement analysis, and selection of appropriate foundation types based on subsurface conditions. Specific foundation types like spread footings, raft foundations, and their analysis are summarized.
This document summarizes the development of an approximate nonlinear analysis method for piled raft foundations. The method models pile-soil interaction, pile-soil-pile interaction, and raft-soil-pile interaction in a multilayered soil profile. It considers effects like apparent stiffness reduction and stiffness hardening. Comparison to 3D FEM analysis shows the method generates similar load-settlement behavior and is sufficiently accurate for design. Further refinement could involve intelligent soil springs and modeling of variable raft shapes, validated through field testing.
This document presents revisions to the Hoek-Brown failure criterion for rock masses. It resolves uncertainties in applying the criterion and incorporating it into numerical models. The revised criterion sets out a recommended calculation sequence and defines equations to determine rock mass strength parameters like cohesive strength and friction angle from the Geological Strength Index rating of rock mass quality. It also distinguishes between undisturbed and disturbed rock masses using a new disturbance factor.
Rock mechanics for engineering geology part 1Jyoti Khatiwada
Rock mass classification systems are used to characterize rock masses for engineering design and stability analysis. The key systems discussed include the Rock Mass Rating (RMR) system, Q-system, Slope Mass Rating (SMR), and the New Austrian Tunnelling Method (NATM) classification. These systems aim to identify significant rock mass parameters, divide rock masses into classes of similar quality, and provide guidelines for design and communication between engineers and geologists. The advantages and limitations of each system are reviewed.
This document provides an overview of laboratory and field testing methods for rocks. It discusses index property tests such as unit weight, porosity, permeability, electrical resistivity, and sonic velocity that are used to characterize and classify rocks. It also describes mechanical property tests like unconfined compressive strength testing, triaxial testing, point load strength testing, and beam bending tests. Common field testing methods mentioned include pressuremeter testing, in-situ direct shear testing, and hydraulic fracturing. The document provides details on sample preparation, equipment used, procedures, and how to calculate and interpret results for different rock property tests.
Rock mechanics focuses on studying the properties and behavior of intact rock and rock masses. Testing of intact rock samples involves destructive strength tests like uniaxial compression and triaxial tests as well as nondestructive tests like Schmidt hammer and sonic wave propagation. The compressive strength test is widely used in rock engineering to determine parameters like the Young's modulus. The complete stress-strain curve obtained from compression testing provides information on the rock's strength, stiffness and failure behavior. Other tests like point load and Brazilian tests are also used to indirectly measure the tensile strength of rock samples.
Pile design summary of ø450, ø600, ø750 and ø900 12, 15 and 20m long -Prakash Rawal
This document provides a calculation of pile design for a cement factory in Nepal to analyze vertical load transfer, lateral shear force, bending moment, and uplift capacity. It summarizes the soil parameters from two borehole investigations, with Borehole 2 found to be more critical. Pile designs are calculated for diameters of 450mm, 600mm, 750mm, and 900mm and lengths of 12m, 15m, and 20m using the GEO5 software. The calculation methodology is described, including determination of soil properties like oedometric modulus. Formulas are provided for calculations of vertical bearing capacity, lateral subgrade modulus, and verification of the pile design. Soil parameters from the three soil layers are also summarized.
EXPERIMENTAL STUDY ON COIR FIBRE REINFORCED FLY ASH BASED GEOPOLYMER CONCRETE...IAEME Publication
Background/Objectives: By using the fly residue as option substance to bond in concrete it reduces the usage of normal Portland cement in usual concrete which results in the development of Geopolymer concrete furthermore in the lessening of CO2 levels which thusly reduces the Global Warming. Methods/Statistical analysis: This paper presents the trial examination done on the execution of coir fibre reinforced fly residue based geopolymer concrete subjected to severe ecological conditions. The mixes were considered for molarity of 10M. The basic arrangement utilized for present revise is the blend of sodium silicate and sodium hydroxide arrangement with the proportion of 1:2.5. Coir fibre with the varying percentages of 0, 0.75, 1.5, 2.25 and 3 are used as fibre reinforcement. The test specimens of 150mmx150mmx150mm cubes, 150mmx300mm cylinders, 1000mmx150mmx150mm beams are cast and cured under encompassing temperature conditions. Findings: The geopolymer solid examples are tried for their compressive quality, flexural and split tractable tests at 7days, 14days and 28days.The test grades demonstrate that the blend of fly ash and coir fibre can be used for the improvement of geopolymer concrete. Applications: It possesses superior distinctiveness such as high strength, very little drying shrinkage , low creep, durable nature, eco-friendly, fire proof ,better compressive strength etc to be used as an alternative of OPC
This document describes a numerical modeling study to predict the strength of St. Peter Sandstone pillars used in underground mining. Finite difference models were created of pillars with dimensions of 12.192 m x 12.192 m x 9.144 m and a room width of 10.3632 m, based on dimensions used successfully in an abandoned Iowa mine. The models applied varying overburden loads to the pillars to determine stress-strain behavior and peak stress. An empirical pillar strength formula was developed and used to establish a relationship between pillar stress, safety factor, and maximum stable overburden depth for factors of safety of 1.5 and 2.
IRJET- A Review on Dynamic Analysis of RCC Building Considering Soil Stru...IRJET Journal
This document provides a literature review on dynamic analysis of reinforced concrete buildings considering soil-structure interaction. It discusses several studies that have used software like SAP2000 to analyze the seismic response of structures on different soil types, considering both flexible base (soil-structure interaction) models and fixed base models. The review covers research using methods like the p-y curve approach and Winkler foundation modeling to represent the soil, and evaluates how soil properties, foundation type, and structural properties influence the seismic behavior of the soil-structure system.
Research Inventy : International Journal of Engineering and Scienceinventy
esearch Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
1. Three new porosity models are proposed to model the relationship between accumulative porosity and pore size in rocks. Experimental results show that one of the models, which relates porosity to the maximum pore size, most closely matches measured pore size distribution data.
2. Pore geometry, orientation, and aspect ratio influence the strength and stiffness of porous rock. Numerical simulations show that compressive strength and Young's modulus decrease as the angle between the major axis of elliptical pores and applied stress increases from 0 to 90 degrees. Strength and stiffness also depend on pore aspect ratio.
3. Two methods for modeling dry bulk modulus at varying porosities are compared - the pore space stiffness method and critical porosity
Shear Strength Of Rockfill, Interfaces And Rock Joints, And Their Pointsguest963b41
The document discusses the shear strength of rockfill, rock joints, and their interfaces and contact points. It finds that the peak shear strength of rockfill and rock joints have similar non-linear strength envelopes when interpreted from large-scale triaxial tests and direct shear tests, respectively. Index tilt tests can also characterize the extremely low stress-dependent shear strength of rockfill and joints. The actual contact stresses when peak shear strength is reached are very high due to small contact areas. Equations are presented to estimate the shear strength of rockfill, rock joints, and their interfaces using characteristics measured from index tests. The non-linear strength envelopes mean that stability factors of safety will reduce from top to bottom and outside to inside
Behaviour of Single Pile in Reinforced Slope Subjected to Inclined Load IJERA Editor
This document summarizes an experimental investigation into the behavior of single piles in reinforced slopes subjected to inclined loading. Model tests were conducted with piles of varying length (10D and 20D) located near a 1V:2H sandy slope reinforced with layers of geogrid. The lateral load capacity of the piles was evaluated by applying loads laterally and at inclinations of 15° and 30°. The load capacity was found to increase with load inclination, pile length, number of geogrid layers, and distance from the slope crest. Load-deflection curves and ultimate lateral load capacities are presented for piles under different test conditions. The results provide insight into pile response based on parameters like reinforced slope design and loading angle.
Analytical study on soil pile interaction effect in the variation of natural ...IAEME Publication
This document summarizes an analytical study on how the natural frequency of a single pile foundation varies with soil-pile interaction effects. It presents the theoretical formulation for calculating the depth of fixity and natural frequency of a pile based on the soil modulus and pile diameter. A finite difference method and MATLAB code were used to model the soil-pile system and conduct a parametric study. The results show that the natural frequency non-linearly decreases with lower soil modulus and smaller pile diameter. An equation was developed through regression analysis to predict the natural frequency based on the soil and pile properties. Understanding how natural frequency varies with soil-pile interaction is important for designing foundations subjected to dynamic loads.
This document discusses different types of piles and their structural characteristics, including steel piles, concrete piles, timber piles, and composite piles. It describes methods of estimating pile length and capacity, including point bearing and friction piles. Equations are provided for estimating the ultimate load-carrying capacity of a pile from its point bearing capacity and frictional resistance. Methods are presented for calculating the point bearing capacity using approaches by Meyerhof, Vesic, and Janbu. The document also discusses estimating the frictional resistance of piles in sand and clay, including the lambda method for clay.
A raft foundation is a large concrete slab that interfaces columns with the base soil. It can support storage tanks, equipment, or tower structures. There are different types including flat plate, plate with thickened columns, and waffle slab. The structural design uses conventional rigid or flexible methods. It involves determining soil pressures, load eccentricities, moment and shear diagrams for strips, punching shear sections, steel reinforcement, and checking stresses. A beam-slab raft foundation design follows the same process as an inverted beam-slab roof.
Numerical Modelling of Boulderly Soil Using Finite Element For Slope Stabilit...Andy Sugianto
1) The document discusses numerical modelling of boulderly soil, which contains rocks and gravel within a clay matrix, using finite element analysis to determine soil parameters for slope stability analysis.
2) It describes conducting triaxial simulation tests in finite element models to observe how the shear strength of boulderly soil increases as the rock and gravel content rises.
3) The results from the numerical modelling are then used to calculate cohesion and friction angle values under the Mohr-Coulomb model and analyze the stability of boulderly soil slopes, finding that realistic rock modelling shows non-circular sliding planes compared to using combined parameters.
Rocks mechanics and its application in mining geology.
It aims at enhancing the mining process and higher yielding by reducing the chance of failures by providing information about the rocks of the mining area.
Numerical and Analytical Solutions for Ovaling Deformation in Circular Tunnel...IDES Editor
Ovaling deformations develop when waves propagate
perpendicular to the tunnel axis. Two analytical solutions are
used for estimating the ovaling deformations and forces in
circular tunnels due to soil–structure interaction under
seismic loading. In this paper, these two closed form solutions
will be described briefly, and then a comparison between these
methods will be made by changing the ground parameters.
Differences between the results of these two methods in
calculating the magnitudes of thrust on tunnel lining are
significant. For verifying the results of these two closed form
solutions, numerical analyses were performed using finite
element code (ABAQUS program). These analyses show that
the two closed form solutions provide the same results only
for full-slip condition.
Numerical simulation of laterally loaded pileDr. Naveen BP
This document presents a finite element model simulation of a lateral load test on a 1m diameter bored pile embedded in residual soils. The pile and soil were modeled in PLAXIS 2D, with the soil represented by a Mohr-Coulomb model and the pile as a beam element. The model results showed good agreement with load-displacement curves from the field test. However, the field test was unable to apply loads high enough to reach design code displacement limits due to limitations of test equipment for large piles in residual soils. The numerical model can simulate larger displacements to evaluate pile behavior under higher loads.
This document discusses a study on the influence of interference between symmetrical footings on the bearing capacity of soil. The study involved plate load tests on square, circular and rectangular footings placed with varying spacing (15 cm and 20 cm) on sand. The results showed that:
1) The ultimate bearing capacity of footings increased as the spacing between them decreased, with capacities up to 20% higher than isolated footings.
2) The efficiency factor, which represents the ratio of bearing capacity of interfering footings to isolated footings, ranged from 0.7 to 1.2 and decreased with increased spacing.
3) Settlement of footings generally remained the same or increased compared to isolated footings, and increased
This document provides an overview of soils investigation and foundation design. It discusses the importance of soils investigation to evaluate subsurface conditions for construction projects. Various field and laboratory techniques are described for soils investigation, including test pits, boreholes, geophysical methods, and laboratory analysis. Factors influencing soil formation such as weathering and transportation are also covered. The document then discusses shallow foundation design, including bearing capacity theory, settlement analysis, and selection of appropriate foundation types based on subsurface conditions. Specific foundation types like spread footings, raft foundations, and their analysis are summarized.
This document summarizes the development of an approximate nonlinear analysis method for piled raft foundations. The method models pile-soil interaction, pile-soil-pile interaction, and raft-soil-pile interaction in a multilayered soil profile. It considers effects like apparent stiffness reduction and stiffness hardening. Comparison to 3D FEM analysis shows the method generates similar load-settlement behavior and is sufficiently accurate for design. Further refinement could involve intelligent soil springs and modeling of variable raft shapes, validated through field testing.
This document presents revisions to the Hoek-Brown failure criterion for rock masses. It resolves uncertainties in applying the criterion and incorporating it into numerical models. The revised criterion sets out a recommended calculation sequence and defines equations to determine rock mass strength parameters like cohesive strength and friction angle from the Geological Strength Index rating of rock mass quality. It also distinguishes between undisturbed and disturbed rock masses using a new disturbance factor.
Rock mechanics for engineering geology part 1Jyoti Khatiwada
Rock mass classification systems are used to characterize rock masses for engineering design and stability analysis. The key systems discussed include the Rock Mass Rating (RMR) system, Q-system, Slope Mass Rating (SMR), and the New Austrian Tunnelling Method (NATM) classification. These systems aim to identify significant rock mass parameters, divide rock masses into classes of similar quality, and provide guidelines for design and communication between engineers and geologists. The advantages and limitations of each system are reviewed.
This document provides an overview of laboratory and field testing methods for rocks. It discusses index property tests such as unit weight, porosity, permeability, electrical resistivity, and sonic velocity that are used to characterize and classify rocks. It also describes mechanical property tests like unconfined compressive strength testing, triaxial testing, point load strength testing, and beam bending tests. Common field testing methods mentioned include pressuremeter testing, in-situ direct shear testing, and hydraulic fracturing. The document provides details on sample preparation, equipment used, procedures, and how to calculate and interpret results for different rock property tests.
Rock mechanics focuses on studying the properties and behavior of intact rock and rock masses. Testing of intact rock samples involves destructive strength tests like uniaxial compression and triaxial tests as well as nondestructive tests like Schmidt hammer and sonic wave propagation. The compressive strength test is widely used in rock engineering to determine parameters like the Young's modulus. The complete stress-strain curve obtained from compression testing provides information on the rock's strength, stiffness and failure behavior. Other tests like point load and Brazilian tests are also used to indirectly measure the tensile strength of rock samples.
Pile design summary of ø450, ø600, ø750 and ø900 12, 15 and 20m long -Prakash Rawal
This document provides a calculation of pile design for a cement factory in Nepal to analyze vertical load transfer, lateral shear force, bending moment, and uplift capacity. It summarizes the soil parameters from two borehole investigations, with Borehole 2 found to be more critical. Pile designs are calculated for diameters of 450mm, 600mm, 750mm, and 900mm and lengths of 12m, 15m, and 20m using the GEO5 software. The calculation methodology is described, including determination of soil properties like oedometric modulus. Formulas are provided for calculations of vertical bearing capacity, lateral subgrade modulus, and verification of the pile design. Soil parameters from the three soil layers are also summarized.
EXPERIMENTAL STUDY ON COIR FIBRE REINFORCED FLY ASH BASED GEOPOLYMER CONCRETE...IAEME Publication
Background/Objectives: By using the fly residue as option substance to bond in concrete it reduces the usage of normal Portland cement in usual concrete which results in the development of Geopolymer concrete furthermore in the lessening of CO2 levels which thusly reduces the Global Warming. Methods/Statistical analysis: This paper presents the trial examination done on the execution of coir fibre reinforced fly residue based geopolymer concrete subjected to severe ecological conditions. The mixes were considered for molarity of 10M. The basic arrangement utilized for present revise is the blend of sodium silicate and sodium hydroxide arrangement with the proportion of 1:2.5. Coir fibre with the varying percentages of 0, 0.75, 1.5, 2.25 and 3 are used as fibre reinforcement. The test specimens of 150mmx150mmx150mm cubes, 150mmx300mm cylinders, 1000mmx150mmx150mm beams are cast and cured under encompassing temperature conditions. Findings: The geopolymer solid examples are tried for their compressive quality, flexural and split tractable tests at 7days, 14days and 28days.The test grades demonstrate that the blend of fly ash and coir fibre can be used for the improvement of geopolymer concrete. Applications: It possesses superior distinctiveness such as high strength, very little drying shrinkage , low creep, durable nature, eco-friendly, fire proof ,better compressive strength etc to be used as an alternative of OPC
This document describes a numerical modeling study to predict the strength of St. Peter Sandstone pillars used in underground mining. Finite difference models were created of pillars with dimensions of 12.192 m x 12.192 m x 9.144 m and a room width of 10.3632 m, based on dimensions used successfully in an abandoned Iowa mine. The models applied varying overburden loads to the pillars to determine stress-strain behavior and peak stress. An empirical pillar strength formula was developed and used to establish a relationship between pillar stress, safety factor, and maximum stable overburden depth for factors of safety of 1.5 and 2.
IRJET- A Review on Dynamic Analysis of RCC Building Considering Soil Stru...IRJET Journal
This document provides a literature review on dynamic analysis of reinforced concrete buildings considering soil-structure interaction. It discusses several studies that have used software like SAP2000 to analyze the seismic response of structures on different soil types, considering both flexible base (soil-structure interaction) models and fixed base models. The review covers research using methods like the p-y curve approach and Winkler foundation modeling to represent the soil, and evaluates how soil properties, foundation type, and structural properties influence the seismic behavior of the soil-structure system.
Research Inventy : International Journal of Engineering and Scienceinventy
esearch Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
1. Three new porosity models are proposed to model the relationship between accumulative porosity and pore size in rocks. Experimental results show that one of the models, which relates porosity to the maximum pore size, most closely matches measured pore size distribution data.
2. Pore geometry, orientation, and aspect ratio influence the strength and stiffness of porous rock. Numerical simulations show that compressive strength and Young's modulus decrease as the angle between the major axis of elliptical pores and applied stress increases from 0 to 90 degrees. Strength and stiffness also depend on pore aspect ratio.
3. Two methods for modeling dry bulk modulus at varying porosities are compared - the pore space stiffness method and critical porosity
Shear Strength Of Rockfill, Interfaces And Rock Joints, And Their Pointsguest963b41
The document discusses the shear strength of rockfill, rock joints, and their interfaces and contact points. It finds that the peak shear strength of rockfill and rock joints have similar non-linear strength envelopes when interpreted from large-scale triaxial tests and direct shear tests, respectively. Index tilt tests can also characterize the extremely low stress-dependent shear strength of rockfill and joints. The actual contact stresses when peak shear strength is reached are very high due to small contact areas. Equations are presented to estimate the shear strength of rockfill, rock joints, and their interfaces using characteristics measured from index tests. The non-linear strength envelopes mean that stability factors of safety will reduce from top to bottom and outside to inside
Behaviour of Single Pile in Reinforced Slope Subjected to Inclined Load IJERA Editor
This document summarizes an experimental investigation into the behavior of single piles in reinforced slopes subjected to inclined loading. Model tests were conducted with piles of varying length (10D and 20D) located near a 1V:2H sandy slope reinforced with layers of geogrid. The lateral load capacity of the piles was evaluated by applying loads laterally and at inclinations of 15° and 30°. The load capacity was found to increase with load inclination, pile length, number of geogrid layers, and distance from the slope crest. Load-deflection curves and ultimate lateral load capacities are presented for piles under different test conditions. The results provide insight into pile response based on parameters like reinforced slope design and loading angle.
Analytical study on soil pile interaction effect in the variation of natural ...IAEME Publication
This document summarizes an analytical study on how the natural frequency of a single pile foundation varies with soil-pile interaction effects. It presents the theoretical formulation for calculating the depth of fixity and natural frequency of a pile based on the soil modulus and pile diameter. A finite difference method and MATLAB code were used to model the soil-pile system and conduct a parametric study. The results show that the natural frequency non-linearly decreases with lower soil modulus and smaller pile diameter. An equation was developed through regression analysis to predict the natural frequency based on the soil and pile properties. Understanding how natural frequency varies with soil-pile interaction is important for designing foundations subjected to dynamic loads.
This document discusses different types of piles and their structural characteristics, including steel piles, concrete piles, timber piles, and composite piles. It describes methods of estimating pile length and capacity, including point bearing and friction piles. Equations are provided for estimating the ultimate load-carrying capacity of a pile from its point bearing capacity and frictional resistance. Methods are presented for calculating the point bearing capacity using approaches by Meyerhof, Vesic, and Janbu. The document also discusses estimating the frictional resistance of piles in sand and clay, including the lambda method for clay.
A raft foundation is a large concrete slab that interfaces columns with the base soil. It can support storage tanks, equipment, or tower structures. There are different types including flat plate, plate with thickened columns, and waffle slab. The structural design uses conventional rigid or flexible methods. It involves determining soil pressures, load eccentricities, moment and shear diagrams for strips, punching shear sections, steel reinforcement, and checking stresses. A beam-slab raft foundation design follows the same process as an inverted beam-slab roof.
Numerical Modelling of Boulderly Soil Using Finite Element For Slope Stabilit...Andy Sugianto
1) The document discusses numerical modelling of boulderly soil, which contains rocks and gravel within a clay matrix, using finite element analysis to determine soil parameters for slope stability analysis.
2) It describes conducting triaxial simulation tests in finite element models to observe how the shear strength of boulderly soil increases as the rock and gravel content rises.
3) The results from the numerical modelling are then used to calculate cohesion and friction angle values under the Mohr-Coulomb model and analyze the stability of boulderly soil slopes, finding that realistic rock modelling shows non-circular sliding planes compared to using combined parameters.
Rocks mechanics and its application in mining geology.
It aims at enhancing the mining process and higher yielding by reducing the chance of failures by providing information about the rocks of the mining area.
Numerical and Analytical Solutions for Ovaling Deformation in Circular Tunnel...IDES Editor
Ovaling deformations develop when waves propagate
perpendicular to the tunnel axis. Two analytical solutions are
used for estimating the ovaling deformations and forces in
circular tunnels due to soil–structure interaction under
seismic loading. In this paper, these two closed form solutions
will be described briefly, and then a comparison between these
methods will be made by changing the ground parameters.
Differences between the results of these two methods in
calculating the magnitudes of thrust on tunnel lining are
significant. For verifying the results of these two closed form
solutions, numerical analyses were performed using finite
element code (ABAQUS program). These analyses show that
the two closed form solutions provide the same results only
for full-slip condition.
Numerical simulation of laterally loaded pileDr. Naveen BP
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IJCER (www.ijceronline.com) International Journal of computational Engineering research
1. International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 5
Determination of Ultimate Lateral Loads in Deep Foundation in Multiple
Layers of Cohessionless Soils
1
B.S.Chawhan, 2S.S.Quadri, 3P.G.Rakaraddi,
1
Asst. Prof, Govt. Engineering College, Haveri-581110,
2
Prof.and Head, BVBCET, Hubli-580031,
3
Associate Professor,BEC, Bagalkot,
Abstract:
This paper presents an experimental investigation on the lateral load carrying capacity of model piles of different flexural
stiffness embedded in loose sand between dense sand and dense sand between loose sand layered soil strata. Attempts has
been made to study the variation of lateral stiffness, eccentricity and soil layer thickness ratio and the effect of various
parameters on the magnitude of Nh. The result of a model tested for the piles embedded in Tungabhadra river sand at Harihar
taluk, Davangere dist, Karnataka State under monotonic lateral loadings. Experimental results are used for the load-deflection
curves (p-y curves) for laterally loaded piles. The proposed p-y curves were compared to the existing curves with Nh and
were evaluated with the experimental data. The ultimate lateral soil resistance and subgrade modulus were investigated and
discussed.
Key words: Subgrade modulus, flexural stiffness, ground line deflection, model tests, piles, soil-pile interaction.
Introduction:
Pile foundations are the most popular form of deep foundations used for both onshore and offshore structures .They are often
used to transfer large loads from the superstructures into deeper, competent soil layers particularly when the structures is to
be located on shallow, weak soil layers. Piles are frequently subjected to lateral forces and moments; for example, in quay
and harbor structures, where horizontal forces are caused by the impact of ships during berthing and wave action; in offshore
structures subjected to wind and wave action; in pile-supported earth retaining structures; in lock structures, in transmission-
tower foundations, where high wind forces may act; and in structures constructed in earthquake areas such as Japan or the
West Coast of the United States.
The ultimate capacity of flexible piles and small pile groups in homogeneous and layered sand has been reported by
Meyerhof and Ghosh 1989. But the state of art does not indicate a definite methodology by which the values of N h can be
obtained. Most of the investigators agree that Nh depends on soil and pile properties and value decreases with the increase in
lateral load. Palmer et.al. (1954) indicated that width of pile has an effect on deflection, pressure and moment along pile even
when flexural stiffness (EI) of pile is kept constant. Murthy (1992) has developed some relationship between Nh and other
parameters like soil properties, flexural strength and lateral load. Dewaikar and Patil (2006) studied the analysis of laterally
loaded pile in cohesionless soil and the Byung Tak Kim, Nak-Kyung Kim, Woo Jin Lee, and Young Su Kim studied the
experimental Load Transfer Curves of Laterally Loaded Piles (April 2004).
This paper presents the experimental investigation of lateral load carrying capacity of model piles of various materials in
homogeneous sand (both in loose and dense state), loose between dense and dense between loose sand layers with
horizontal loads acting at various eccentricities. In all the tests, the outer diameter (d) and depth of embedment (D) of piles
are kept constant.
Experimental Set-Up and Model Tests
The test were carried in Tungabhadra river sand at Harihar taluk, Davangere dist, Karnataka State and having placement
density of 13.35kN/m3 and Φ=310 for loose soil condition and 15.89kN/m3, Φ=390 for dense condition. The tests were
conducted in two steps. a) The soil condition is loose sand layer between dense sand layer with H/D ratio of 0.25, 0.50, 0.75,
and 0.90. b) The soil condition is dense sand layer between loose sand layer with H/D ratio of 0.25, 0.50, 0.75,and 0.90,
where H is the thickness of middle layer and D is the total depth of embedment of the pile(=594mm). In both the cases the
eccentricities of 0, 50, 100, 150 and 200mm are conducted in homogeneous loose sand layer and dense sand layer. The
outside diameters of the piles are 25mm for solid Steel and Wooden Piles. Hollow Aluminium pile with 25mm outside and
0.3mm thickness. The embedment depths of all the piles are 594mm. The flexural rigidity of steel, wooden and Aluminium
piles were 642.106Nm2, 506.12Nm2 and 51.041Nm2 respectively. The relative stiffness factors for steel, wooden and
Aluminium were 0.1192, 0.939 and 0.0094 respectively for Loose sand layer and 0.0263, 0.0207 and 0.0020 for Dense sand
layer. The horizontal displacement and rotation of pile cap are recorded by L.V.D.T. and two dial gauges. The stabilized
‘Rainfall-Technique’ this standard technique is available in standard literature and this technique was used to pour the sand
in the testing steel tank. Figure.1 shows schematic sketch of experimental setup.
Issn 2250-3005(online) September| 2012 Page 1640
2. International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 5
Fig.1 Schematic sketch of experimental setup
The ultimate load bearing capacity of model piles are obtained from load deflection curves by the following criteria.
(A). Single tangent method
(B). Double tangent method
(C). Load corresponding to ground line deflection
equal to 10% pile diameter
(D).Load corresponding to ground line deflection equal to 20% pile diameter
(E). Log-Log method.
It is observed that different criteria yield different ultimate load (vide Table-1). For the present analysis, the average of first
three criteria is taken as ultimate pile capacity.
Method Of Analysis
Reese and Matlock (1956) have developed a set of equations based on dimensional analysis for computing deflection, slope,
moment etc, along the pile. These equations are very useful for predicting the non-linear behavior of laterally loaded piles
provided the magnitude of Nh is known at each load level. For deflection and slope of free head pile at ground level, the
following equations are given by Reese and Matlock (1956).
2.435PT 3 1.62MT 2
Yg (1)
EI EI
2
1.62 PT 1.75MT (2)
Sg
EI EI
1
where,Relative Stiffness factor T EI
n4
N
(3)
h
P=Lateral load at pile head; M=Moment at pile head (=P*e); e=Eccentricity of horizontal load measured from ground level;
and EI=Flexural stiffness of the model pile.
From the observed lateral resistance and corresponding ground line deflection and rotation, the value of coefficient of soil
modulus variation Nh is estimated for different types of model piles by using the above equations (1) and (2).
Murthy .V.N.S (1976) has proposed the equations for determining Nh in cohesionless soil at each stage of loading as
A
Nh m
(4)
Pt
where Pt= Lateral load at pile head, m is a constant equal to 0.8 and A is a factor which is a function of the effective unit
156C f 1.5 EIB 2
1
weight γ of the soil and flexural stiffness EI of the pile. A
Nh s
Pt P
(5)
where, Pt=Lateral load; As=Constant for pile in sand; P=Pt(1+0.67e/T); and Cf =Correction factor for the angle of friction =
3*10-5(1.315) Φ, where Φ is in degrees.
Results And Discussions
The experimental results were carried out and tabulated in following Table-1 and Table-2.
Table-1 presents ultimate loads of model Aluminium piles (embedded in Dense between loose sand layer) estimated from
observed load deflection curves using different criteria mentioned earlier. It can be noted that ultimate load of a pile is not
unique but depends on different methods or criteria. Table-2 presents ultimate loads of different pile materials in Loose
between Dense layers estimated from observed experimental values. It can be noted that ultimate lateral resistance of pile
decreases with the increase of H/D ratio in Loose between dense sand layer where as it increases with the increase of H/D
ratio in Dense between Loose sand layer. Fig.2 shows typical load deflection curves of steel, wooden and aluminium piles
embedded in loose sand between dense sand layer with e=50mm, H/D=0.25. In fig.3 the lateral load deflection curves of
aluinium pile embedded in dense sand between loose sand layer having H/D=0.9 with varying eccentricity. The figure reveals
that ultimate lateral resistance of pile decreases with increase in eccentricity. This phenomena is observed in all types of
Issn 2250-3005(online) September| 2012 Page 1641
3. International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 5
model piles irrespective of all condition (i.e loose sand layer, dense sand layer, loose sand layer between dense sand layer and
dense sand layer between loose sand layer).
In fig.4 the variation of coefficient of soil modulus v/s flexural stiffness(EI) curve of three model piles in dense between
loose sand layer having h/D=0.90 with varying eccentricity. The figure reveals that flexural stiffness of pile increases with
increase in variation of coefficient of soil modulus. This phenomena is observed in all conditions of soil layers.
In fig.5 indicates the variation ultimate load of model piles with flexural stiffness EI when they are embedded in dense sand
layer between loose sand layer having various H/D ratio and e=50mm. this reveals that ultimate load increases with increase
in flexural stiffness of pile when all other conditions are kept constant.
Table-1.Comparison of ultimate load (N) by various methods (Aluminium pile, H/D=0.5, Dense between loose sand layer).
Methods
Eccentricity, e in mm
(Different Criteria)
e (mm) A B C D E
50 20 14 16 32 33
100 19 19 15 26 33
150 12 09 12 24 26
200 10 08 08 22 24
Table-2. Ultimate load (N) of different pile (Steel, Wooden, and Aluminium pile, H/D=0.5, Dense between Loose sand
layer).
Eccentricity, Alum
H/D Steel Wooden
e in mm inum
50 0.50 16.96 29.66 14.98
100 0.50 13.04 22.82 11.52
150 0.50 11.74 20.54 10.37
200 0.50 10.43 18.25 9.22
Dense sand layer between loose
sand layer, H/D=0.9
Issn 2250-3005(online) September| 2012 Page 1642
4. International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 5
Dense sand layer between loose
sand layer, H/D=0.9
Fig.4. Variation of soil modulus Nh with Flexural stiffness of piles embedded in dense between loose sand layer,
H/D=0.90, n=2/3.
Fig.5. Variation of ultimate load with Flexural stiffness of piles embedded in dense between loose sand layer.
Conclusions
The following conclusions are made based on the experimental investigations.
(i) The ultimate lateral resistance of single pile
decreases with the increase in eccentricity of
load, it is about 8 to 11%.
(ii) The ultimate resistance of single pile subjected to
horizontal load decreases with increase in eccentricity of load on the same pile provided the depth of embedment
remains constant for homogeneous loose and dense layers, also loose between dense and dense between loose
layered soils, and it is about 10 to 12%.
(iii) The ultimate lateral resistance of pile increases
with increased value of flexural stiffness of pile and it is about 8 to 13% and the magnitude of Nh decreases with the
increase in magnitude of horizontal load irrespective of flexural stiffness of pile and soil condition.
(iv) In dense sand, the magnitude of Nh increases with the increase in value of flexural stiffness of pile where as in case
of loose sand the value decreases with the increase in EI value of piles and the ultimate lateral load carried is more
(10 to 12%) in dense between loose sand layer and vice versa.
The tests may be conducted in multiple layers of Loose sand layer and Dense sand layer with constant and variable
thickness of layers and also the Variation of Coefficient of soil modulus (Nh) in a different soil layers along the
depth can be studied.
Issn 2250-3005(online) September| 2012 Page 1643
5. International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 5
REFERENCES
[1.] Byung Tak Kim, nak-Kyung Kim, Woo Jin, Lee
[2.] and Young Su Kim. (2004), Experimental Load- Transfer Curves of Laterally Loaded Piles In Nak-Dong River
Sand, Journal of Geotechnical and Geoenvironmental Engineering, 130(4),416-425.
[3.] Dewaikar D.M and Patil P.A. (2006), Analysis
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[5.] Dewaikar D.M and Patil, D.S.(2001), Behaviour
[6.] of laterally loaded piles in cohesion-less soil under oneway cyclic loading, The New Millennium Conference, 14-
16 December-2001.
[7.] Ghosh,D.P and Meyerhof,G.G.(1989), The
[8.] ultimate bearing capacity of flexible piles in layered sand under eccentric and inclined loads, Indian Geotech.J,(19)3,
187-201.
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