This document discusses landslide tsunamis, which occur when large landslides enter bodies of water with enough force to generate destructive waves. It provides background on tsunami wave physics, then focuses on two specific cases: the 1958 Lituya Bay landslide tsunami and the 1963 Vajont Dam landslide tsunami. Factors that influence landslide tsunami generation include the landslide volume and velocity, as well as properties of the receiving body of water like depth. The Froude number, which represents the ratio of landslide velocity to shallow water wave speed, helps determine resulting wave type from solitary to oscillatory.
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.
Boundary layer concept for external flowManobalaa R
This document provides an overview of boundary layer concepts for external flow. It defines a boundary layer as the layer of fluid near a bounding surface where viscous effects are significant. It describes the assumptions of boundary layer theory, including that viscous effects are confined to the thin boundary layer. It also provides the governing equations for a 2D, laminar, steady boundary layer and discusses boundary layer thickness. Finally, it briefly summarizes literature on an experimental study of film cooling in a rotating turbine.
Friction is the resistance to motion when one solid body moves over another in contact. There are two main types of friction: dry friction and fluid friction. Dry friction, also called Coulomb friction, occurs between two dry surfaces in contact. Fluid friction occurs between layers of a fluid moving at different velocities.
The document discusses the mechanisms and theories of friction. It explains that friction arises from interactions between surface asperities or roughness. The dominant mechanisms are adhesion between contact areas and plastic deformation. Adhesion contributes to friction through the force needed to overcome molecular bonds between contacting asperities. Deformation friction is the energy required for plastic plowing or deformation of asperities. The total friction force is the sum
This document discusses various methods for analyzing the stability of finite slopes, including the Swedish circle method, friction circle method, Taylor stability number method, Bishop's method, and Culmann's method. The Swedish circle method models the failure surface as an arc of a circle and considers cases of purely cohesive soil and cohesive-frictional soil. The friction circle method also assumes a circular failure surface and models resisting forces. Taylor's stability number relates the stabilizing cohesive force to the slope height and cohesion. Bishop's method accounts for inter-slice forces and pore water pressure. Culmann's method assumes a planar failure surface passing through the toe.
Wave-Current Interaction Model on an Exponential Profileijceronline
We develop a model that approximates the exponential depth, which exhibits the behavior of linear depth particularly in the surf zone. The main effect of the present exponential depth is found in the shoaling zone, where the depth remains finite. The basic description and the outcome is essentially rip currents where in the surf zone the wave behavior is the same as found in the linear depth case. In the shoaling zone the present exponential depth exhibits the hypergeometric functions.
When the safety factor of natural or artificial slopes reaches critical value of 1.0, the increment of triggering factors, i.e. precipitation, rise of groundwater level, earthquake, and slope interference may prompt slope failure. Considering the impacts and damages possibly caused by rapid landslides, it is important to predict its runout distance, velocity, moving volume, and coverage area. A numerical model was developed to calculate the rapid landslide motion and applied to 26 cases of landslides and 6 cases of debris flows, with volume ranging from less than 100 m3 up to 3.5 9 109 m3. This quasi-three-dimensional model used the Navier–Stokes equation as the governing equation of motion and Coulomb’s resistance rule along the sliding surface to compute runout distance and coverage area corresponding with the real rheological conditions in the field. Due to the influence of dynamic conditions and excess pore water pressure, the internal friction of the sliding mass and the sliding surface are much smaller than the internal friction obtained by static soil tests. The moving volume affects the dynamic coefficient of friction and the velocity, whereas a small volume landslide occurs at a higher value of dynamic coefficient of friction and yields lower velocity. In addition, a landslide with a gentler slope occurs at a lower value of dynamic coefficient of friction, where in the case of the debris flow, it tends to have an even lower dynamic friction compared to landslide. This numerical model can be used to simulate the motion of rapid landslides with potentially long run-out in order to support hazard and risk assessment of landslides.
The document discusses fluid mechanics concepts including:
1) Boundary layers form as fluid flows past objects due to viscosity and velocity gradients within the boundary layer.
2) Drag and lift are forces exerted on objects by fluid flow and depend on factors like boundary layer thickness, pressure distribution, and object shape.
3) The Reynolds number compares inertia and viscous forces and indicates laminar or turbulent flow.
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.
Boundary layer concept for external flowManobalaa R
This document provides an overview of boundary layer concepts for external flow. It defines a boundary layer as the layer of fluid near a bounding surface where viscous effects are significant. It describes the assumptions of boundary layer theory, including that viscous effects are confined to the thin boundary layer. It also provides the governing equations for a 2D, laminar, steady boundary layer and discusses boundary layer thickness. Finally, it briefly summarizes literature on an experimental study of film cooling in a rotating turbine.
Friction is the resistance to motion when one solid body moves over another in contact. There are two main types of friction: dry friction and fluid friction. Dry friction, also called Coulomb friction, occurs between two dry surfaces in contact. Fluid friction occurs between layers of a fluid moving at different velocities.
The document discusses the mechanisms and theories of friction. It explains that friction arises from interactions between surface asperities or roughness. The dominant mechanisms are adhesion between contact areas and plastic deformation. Adhesion contributes to friction through the force needed to overcome molecular bonds between contacting asperities. Deformation friction is the energy required for plastic plowing or deformation of asperities. The total friction force is the sum
This document discusses various methods for analyzing the stability of finite slopes, including the Swedish circle method, friction circle method, Taylor stability number method, Bishop's method, and Culmann's method. The Swedish circle method models the failure surface as an arc of a circle and considers cases of purely cohesive soil and cohesive-frictional soil. The friction circle method also assumes a circular failure surface and models resisting forces. Taylor's stability number relates the stabilizing cohesive force to the slope height and cohesion. Bishop's method accounts for inter-slice forces and pore water pressure. Culmann's method assumes a planar failure surface passing through the toe.
Wave-Current Interaction Model on an Exponential Profileijceronline
We develop a model that approximates the exponential depth, which exhibits the behavior of linear depth particularly in the surf zone. The main effect of the present exponential depth is found in the shoaling zone, where the depth remains finite. The basic description and the outcome is essentially rip currents where in the surf zone the wave behavior is the same as found in the linear depth case. In the shoaling zone the present exponential depth exhibits the hypergeometric functions.
When the safety factor of natural or artificial slopes reaches critical value of 1.0, the increment of triggering factors, i.e. precipitation, rise of groundwater level, earthquake, and slope interference may prompt slope failure. Considering the impacts and damages possibly caused by rapid landslides, it is important to predict its runout distance, velocity, moving volume, and coverage area. A numerical model was developed to calculate the rapid landslide motion and applied to 26 cases of landslides and 6 cases of debris flows, with volume ranging from less than 100 m3 up to 3.5 9 109 m3. This quasi-three-dimensional model used the Navier–Stokes equation as the governing equation of motion and Coulomb’s resistance rule along the sliding surface to compute runout distance and coverage area corresponding with the real rheological conditions in the field. Due to the influence of dynamic conditions and excess pore water pressure, the internal friction of the sliding mass and the sliding surface are much smaller than the internal friction obtained by static soil tests. The moving volume affects the dynamic coefficient of friction and the velocity, whereas a small volume landslide occurs at a higher value of dynamic coefficient of friction and yields lower velocity. In addition, a landslide with a gentler slope occurs at a lower value of dynamic coefficient of friction, where in the case of the debris flow, it tends to have an even lower dynamic friction compared to landslide. This numerical model can be used to simulate the motion of rapid landslides with potentially long run-out in order to support hazard and risk assessment of landslides.
The document discusses fluid mechanics concepts including:
1) Boundary layers form as fluid flows past objects due to viscosity and velocity gradients within the boundary layer.
2) Drag and lift are forces exerted on objects by fluid flow and depend on factors like boundary layer thickness, pressure distribution, and object shape.
3) The Reynolds number compares inertia and viscous forces and indicates laminar or turbulent flow.
This document summarizes a student's final term project analyzing fluid flow around a cannon ball. The student will use computational fluid dynamics (CFD) software to simulate air flow around a spherical cannon ball moving in a projectile motion. Key results to be obtained from the CFD analysis include boundary layer thickness, displacement thickness, momentum thickness, shape factor, drag coefficient, and velocity and pressure distributions. The student outlines the cannon ball geometry, meshing approach, governing equations, and parameters that will be analyzed to understand the transition between laminar and turbulent flow around the moving sphere.
This document discusses linear and non-linear elasticity concepts relevant to rock mechanics. It defines key terms like stress, strain, elastic moduli, and principal stresses/strains. It describes how stress and strain relate for isotropic materials using Hooke's law and elastic constants. It also covers the stress tensor, Mohr's circle, strain energy, and the differences between linear, perfectly elastic, elastic with hysteresis, and permanently deforming non-linear elastic models.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
1. Soil slopes become unstable when the shear stress along a failure plane exceeds the shear strength of the soil. This can occur along distinct layers within a slope.
2. One defined failure plane is the interface between a sloping soil layer and an underlying impermeable layer. The overlying soil is prone to sliding failure along this interface.
3. Stability charts can be used to analyze slope failures in cohesive soils, accounting for soil cohesion, internal friction angle, and slope geometry.
1. Rotational slope failures occur along a circular surface and theories are based on particles in rockmasses being small and not interlocked.
2. Stability charts are derived using assumptions like homogeneous material, shear strength equations, and failure surfaces passing through the slope toe.
3. Factor of safety is defined as the ratio of shear strength available to resist sliding to the shear stress required for equilibrium. Charts are used to locate failure surfaces and tension cracks for different groundwater conditions.
The document defines the coefficient of friction and describes the relationship between frictional force, normal force, and other variables. There are two types of friction: static friction, which acts when an object tries to begin moving, and kinetic friction, which acts when an object is already in motion. The frictional force is calculated as the coefficient of friction multiplied by the normal force on the object's surface. For horizontal surfaces, the normal force is equal to the object's weight. The document notes that static friction coefficients are not always higher than kinetic/dynamic coefficients, as commonly believed, especially for brake materials.
Modeling the combined effect of surface roughness and shear rate on slip flow...Nikolai Priezjev
Molecular dynamics MD and continuum simulations are carried out to investigate the influence of shear rate and surface roughness on slip flow of a Newtonian fluid. For weak wall-fluid interaction energy, the nonlinear shear-rate dependence of the intrinsic slip length in the flow over an atomically flat surface is computed by MD simulations. We describe laminar flow away from a curved boundary by means of the effective slip length defined with respect to the mean height of the surface roughness. Both the magnitude of the effective slip length and the slope of its rate dependence are significantly reduced in the presence of periodic surface roughness. We then numerically solve the Navier-Stokes equation for the flow over the rough surface using the rate-dependent intrinsic slip length as a local boundary condition. Continuum simulations reproduce the behavior of the effective slip length obtained from MD simulations at low shear rates. The slight discrepancy between MD and continuum results at high shear rates is explained by examination of the local velocity profiles and the pressure distribution along the wavy surface. We found that in the region where the curved boundary faces the mainstream flow, the local slip is suppressed due to the increase in pressure. The results of the comparative analysis can potentially lead to the development of an efficient algorithm for modeling rate dependent slip flows over rough surfaces.
The document discusses boundary layer concepts and applications including:
1) Boundary layer thicknesses such as displacement thickness and momentum thickness.
2) The exact solution of laminar flow over a flat plate including the governing equations and Blasius solution.
3) Using the momentum integral equation to estimate boundary layer thickness for flows with zero pressure gradient, comparing laminar and turbulent flow results.
4) Drag concepts including friction drag on flat plates and pressure drag on spheres and cylinders, and how streamlining can reduce pressure drag.
5) Lift concepts including characteristics of airfoils and induced drag.
This document discusses concepts of failure in materials including tensile failure, shear failure, and failure criteria. It specifically examines the Mohr-Coulomb failure criterion, which states that failure depends on the material's cohesion and internal friction angle. The criterion can be represented on a Mohr's circle diagram, where failure occurs if the circle contacts the linear failure envelope line. Pore fluid pressure is also accounted for using effective stress. Triaxial tests are described that apply different confining pressures to measure failure properties over a range of stress conditions.
This document discusses stress and strain ellipsoids in structural geology. It defines stress as a force applied over an area that causes rock deformation. Stress can be tensional, compressional, or shear. Strain is the response of rock to stress and describes the change in shape of an object under stress. Stress and strain are represented geometrically using ellipsoids. The relationship between stress and strain ellipsoids is that the greatest and least axes are opposite. The orientation of stress and strain ellipsoids provides information about the deformative forces acting on rocks.
The document discusses slope stability and factors that influence it. It defines an unrestrained slope and describes different types of slope failures such as base failures and midpoint circle failures. Factors that influence slope stability include soil/rock strength, groundwater, external loading, and slope geometry. Slope failures can be triggered by erosion, rainfall, earthquakes, and construction activities. Methods to improve slope stability include flattening slopes, adding weight/retaining walls, lowering the water table, soil improvement. Stability analyses procedures include mass and slices methods. The factor of safety is defined and equations for infinite slope analysis with and without seepage are provided.
Gravity Dam (numerical problem ) BY SITARAM SAINISitaramSaini11
The document discusses the analysis of a gravity dam, including calculating stresses and checking stability, for both an empty reservoir and full reservoir condition. It provides numerical examples of determining vertical stresses, principal stresses, and shear stresses at the toe and heel of the dam. It also shows calculations for checking the stability of the dam against sliding, overturning, tension and sufficient shear resistance.
Numerical Study of Strong Free Surface Flow and Wave BreakingYi Liu
1. The document describes numerical methods for simulating strong free surface flows and wave breaking, including the coupled level set and volume-of-fluid method.
2. Results are presented from simulations of breaking waves under different wind conditions, showing the generation of vortices and effect of wind speed on wave breaking.
3. Future research topics discussed include studying wave breaking mechanisms under different conditions, the interaction of wind turbulence and breaking waves, and multi-scale simulations of wind-wave-structure interaction using immersed boundary methods.
TECHNIQUES FOR MEASUREMENT OF IN-SITU STRESSESShah Naseer
The Mohr Coulomb failure criterion describes the relationship between normal and shear stresses at failure through a linear equation. It represents the peak shear strength of a material as a function of the applied normal stress and the angle of internal friction. The criterion is commonly used in geotechnical analysis but has limitations as it assumes shear failure and does not account for non-linear failure envelopes or the intermediate principal stress.
The document describes a study that tested the shear strength of clay soil samples from the Rattlesnake Gulf landslide in New York's Tully Valley. The study used an Autoshear device to measure shear stress, vertical displacement, and horizontal load in order to analyze shear strength parameters. The results will help understand what makes the area susceptible to landslides and inform slope stability analysis. A literature review covers concepts of slope stability, shear strength testing, and factors influencing landslides in the Tully Valley region.
This document discusses load calculation methods for building structures. It describes different types of loads including dead loads from structural elements, live loads from movable objects, and lateral loads from wind and earthquakes. It provides details on calculating dead loads for reinforced concrete slabs, including slab thickness determination using span length. An example calculation is given for the dead load per meter of a ribbed one-way slab based on the thickness, material densities, and weights of slab components like tiles, mortar, fill, and hollow blocks. The total calculated dead load for this example slab is 10.33 kN/m2.
Mohr circle mohr circle anaysisand applicationShivam Jain
Mohr's circle is a graphical representation used to analyze the state of stress at a point. It relates the normal and shear stresses acting on planes of all orientations passing through that point. The document discusses how to construct Mohr's circle through an example and how it can be used to analyze principal stresses, maximum shear stress, and normal and shear stresses on any given plane. Applications of Mohr's circle include analyzing brittle and ductile deformation, the effects of pore pressure, and detecting stability in structures like bridges, dams, and slopes.
The document discusses the concept of friction. It defines friction as the resisting force along the surfaces of contact that opposes the motion of one body moving over another. It states that the magnitude of the frictional force depends on factors like the materials of the surfaces in contact, the roughness of the surfaces, and the pressure between them. It also distinguishes between different types of friction like static friction, dynamic friction, sliding friction, and rolling friction.
This document provides information about strain analysis and the relationship between stress and strain. Some key points:
- Strain is defined as the change in size and shape of a body resulting from an applied stress. Kinematic analysis is used to reconstruct deformation.
- There are different types of strain including elastic, brittle, and plastic, which depend on the magnitude and rate of applied stress. Homogeneous and inhomogeneous strain can occur.
- Strain is measured using various techniques at different scales from regional to microscopic. Equations relate changes in length, shear, and elongation to strain.
- The relationship between stress and strain in rocks is evaluated experimentally. Stress-strain diagrams show properties like strength and duct
Stress is the internal resistance of a material against an applied load or force. There are different types of stress that rocks can experience, including lithostatic stress from the weight of overlying rocks, and differential stress from tectonic forces like tension, compression, and shearing. Rocks deform in response to stress in different ways depending on factors like pressure, temperature, and composition. At low stresses rocks deform elastically and return to their original shape when unloaded. At higher stresses near the surface, rocks deform brittlely and fracture. Deeper underground, higher temperatures cause ductile deformation where rocks flow plastically. The stress-strain behavior of rocks is important for understanding their mechanical properties and failure under stress
This document summarizes a student's final term project analyzing fluid flow around a cannon ball. The student will use computational fluid dynamics (CFD) software to simulate air flow around a spherical cannon ball moving in a projectile motion. Key results to be obtained from the CFD analysis include boundary layer thickness, displacement thickness, momentum thickness, shape factor, drag coefficient, and velocity and pressure distributions. The student outlines the cannon ball geometry, meshing approach, governing equations, and parameters that will be analyzed to understand the transition between laminar and turbulent flow around the moving sphere.
This document discusses linear and non-linear elasticity concepts relevant to rock mechanics. It defines key terms like stress, strain, elastic moduli, and principal stresses/strains. It describes how stress and strain relate for isotropic materials using Hooke's law and elastic constants. It also covers the stress tensor, Mohr's circle, strain energy, and the differences between linear, perfectly elastic, elastic with hysteresis, and permanently deforming non-linear elastic models.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
1. Soil slopes become unstable when the shear stress along a failure plane exceeds the shear strength of the soil. This can occur along distinct layers within a slope.
2. One defined failure plane is the interface between a sloping soil layer and an underlying impermeable layer. The overlying soil is prone to sliding failure along this interface.
3. Stability charts can be used to analyze slope failures in cohesive soils, accounting for soil cohesion, internal friction angle, and slope geometry.
1. Rotational slope failures occur along a circular surface and theories are based on particles in rockmasses being small and not interlocked.
2. Stability charts are derived using assumptions like homogeneous material, shear strength equations, and failure surfaces passing through the slope toe.
3. Factor of safety is defined as the ratio of shear strength available to resist sliding to the shear stress required for equilibrium. Charts are used to locate failure surfaces and tension cracks for different groundwater conditions.
The document defines the coefficient of friction and describes the relationship between frictional force, normal force, and other variables. There are two types of friction: static friction, which acts when an object tries to begin moving, and kinetic friction, which acts when an object is already in motion. The frictional force is calculated as the coefficient of friction multiplied by the normal force on the object's surface. For horizontal surfaces, the normal force is equal to the object's weight. The document notes that static friction coefficients are not always higher than kinetic/dynamic coefficients, as commonly believed, especially for brake materials.
Modeling the combined effect of surface roughness and shear rate on slip flow...Nikolai Priezjev
Molecular dynamics MD and continuum simulations are carried out to investigate the influence of shear rate and surface roughness on slip flow of a Newtonian fluid. For weak wall-fluid interaction energy, the nonlinear shear-rate dependence of the intrinsic slip length in the flow over an atomically flat surface is computed by MD simulations. We describe laminar flow away from a curved boundary by means of the effective slip length defined with respect to the mean height of the surface roughness. Both the magnitude of the effective slip length and the slope of its rate dependence are significantly reduced in the presence of periodic surface roughness. We then numerically solve the Navier-Stokes equation for the flow over the rough surface using the rate-dependent intrinsic slip length as a local boundary condition. Continuum simulations reproduce the behavior of the effective slip length obtained from MD simulations at low shear rates. The slight discrepancy between MD and continuum results at high shear rates is explained by examination of the local velocity profiles and the pressure distribution along the wavy surface. We found that in the region where the curved boundary faces the mainstream flow, the local slip is suppressed due to the increase in pressure. The results of the comparative analysis can potentially lead to the development of an efficient algorithm for modeling rate dependent slip flows over rough surfaces.
The document discusses boundary layer concepts and applications including:
1) Boundary layer thicknesses such as displacement thickness and momentum thickness.
2) The exact solution of laminar flow over a flat plate including the governing equations and Blasius solution.
3) Using the momentum integral equation to estimate boundary layer thickness for flows with zero pressure gradient, comparing laminar and turbulent flow results.
4) Drag concepts including friction drag on flat plates and pressure drag on spheres and cylinders, and how streamlining can reduce pressure drag.
5) Lift concepts including characteristics of airfoils and induced drag.
This document discusses concepts of failure in materials including tensile failure, shear failure, and failure criteria. It specifically examines the Mohr-Coulomb failure criterion, which states that failure depends on the material's cohesion and internal friction angle. The criterion can be represented on a Mohr's circle diagram, where failure occurs if the circle contacts the linear failure envelope line. Pore fluid pressure is also accounted for using effective stress. Triaxial tests are described that apply different confining pressures to measure failure properties over a range of stress conditions.
This document discusses stress and strain ellipsoids in structural geology. It defines stress as a force applied over an area that causes rock deformation. Stress can be tensional, compressional, or shear. Strain is the response of rock to stress and describes the change in shape of an object under stress. Stress and strain are represented geometrically using ellipsoids. The relationship between stress and strain ellipsoids is that the greatest and least axes are opposite. The orientation of stress and strain ellipsoids provides information about the deformative forces acting on rocks.
The document discusses slope stability and factors that influence it. It defines an unrestrained slope and describes different types of slope failures such as base failures and midpoint circle failures. Factors that influence slope stability include soil/rock strength, groundwater, external loading, and slope geometry. Slope failures can be triggered by erosion, rainfall, earthquakes, and construction activities. Methods to improve slope stability include flattening slopes, adding weight/retaining walls, lowering the water table, soil improvement. Stability analyses procedures include mass and slices methods. The factor of safety is defined and equations for infinite slope analysis with and without seepage are provided.
Gravity Dam (numerical problem ) BY SITARAM SAINISitaramSaini11
The document discusses the analysis of a gravity dam, including calculating stresses and checking stability, for both an empty reservoir and full reservoir condition. It provides numerical examples of determining vertical stresses, principal stresses, and shear stresses at the toe and heel of the dam. It also shows calculations for checking the stability of the dam against sliding, overturning, tension and sufficient shear resistance.
Numerical Study of Strong Free Surface Flow and Wave BreakingYi Liu
1. The document describes numerical methods for simulating strong free surface flows and wave breaking, including the coupled level set and volume-of-fluid method.
2. Results are presented from simulations of breaking waves under different wind conditions, showing the generation of vortices and effect of wind speed on wave breaking.
3. Future research topics discussed include studying wave breaking mechanisms under different conditions, the interaction of wind turbulence and breaking waves, and multi-scale simulations of wind-wave-structure interaction using immersed boundary methods.
TECHNIQUES FOR MEASUREMENT OF IN-SITU STRESSESShah Naseer
The Mohr Coulomb failure criterion describes the relationship between normal and shear stresses at failure through a linear equation. It represents the peak shear strength of a material as a function of the applied normal stress and the angle of internal friction. The criterion is commonly used in geotechnical analysis but has limitations as it assumes shear failure and does not account for non-linear failure envelopes or the intermediate principal stress.
The document describes a study that tested the shear strength of clay soil samples from the Rattlesnake Gulf landslide in New York's Tully Valley. The study used an Autoshear device to measure shear stress, vertical displacement, and horizontal load in order to analyze shear strength parameters. The results will help understand what makes the area susceptible to landslides and inform slope stability analysis. A literature review covers concepts of slope stability, shear strength testing, and factors influencing landslides in the Tully Valley region.
This document discusses load calculation methods for building structures. It describes different types of loads including dead loads from structural elements, live loads from movable objects, and lateral loads from wind and earthquakes. It provides details on calculating dead loads for reinforced concrete slabs, including slab thickness determination using span length. An example calculation is given for the dead load per meter of a ribbed one-way slab based on the thickness, material densities, and weights of slab components like tiles, mortar, fill, and hollow blocks. The total calculated dead load for this example slab is 10.33 kN/m2.
Mohr circle mohr circle anaysisand applicationShivam Jain
Mohr's circle is a graphical representation used to analyze the state of stress at a point. It relates the normal and shear stresses acting on planes of all orientations passing through that point. The document discusses how to construct Mohr's circle through an example and how it can be used to analyze principal stresses, maximum shear stress, and normal and shear stresses on any given plane. Applications of Mohr's circle include analyzing brittle and ductile deformation, the effects of pore pressure, and detecting stability in structures like bridges, dams, and slopes.
The document discusses the concept of friction. It defines friction as the resisting force along the surfaces of contact that opposes the motion of one body moving over another. It states that the magnitude of the frictional force depends on factors like the materials of the surfaces in contact, the roughness of the surfaces, and the pressure between them. It also distinguishes between different types of friction like static friction, dynamic friction, sliding friction, and rolling friction.
This document provides information about strain analysis and the relationship between stress and strain. Some key points:
- Strain is defined as the change in size and shape of a body resulting from an applied stress. Kinematic analysis is used to reconstruct deformation.
- There are different types of strain including elastic, brittle, and plastic, which depend on the magnitude and rate of applied stress. Homogeneous and inhomogeneous strain can occur.
- Strain is measured using various techniques at different scales from regional to microscopic. Equations relate changes in length, shear, and elongation to strain.
- The relationship between stress and strain in rocks is evaluated experimentally. Stress-strain diagrams show properties like strength and duct
Stress is the internal resistance of a material against an applied load or force. There are different types of stress that rocks can experience, including lithostatic stress from the weight of overlying rocks, and differential stress from tectonic forces like tension, compression, and shearing. Rocks deform in response to stress in different ways depending on factors like pressure, temperature, and composition. At low stresses rocks deform elastically and return to their original shape when unloaded. At higher stresses near the surface, rocks deform brittlely and fracture. Deeper underground, higher temperatures cause ductile deformation where rocks flow plastically. The stress-strain behavior of rocks is important for understanding their mechanical properties and failure under stress
This document discusses the rise of citizen journalism and user-generated media content. It notes how affordable technologies like smartphones and laptops have enabled people to document and share their own perspectives. Examples are given of activists in Egypt using these tools to spread information during the Arab Spring protests in 2011. The document also discusses how social media allows for new forms of "DIY" activism and civic engagement. It argues teachers should harness this energy by bringing play, arts, and hands-on activities into the classroom to engage students in self-directed learning.
The document discusses guidelines for caring for patients in the postoperative period following tracheostomy. The goals of postoperative care are to enable faster recovery, reduce mortality and hospital stay, and provide quality care. Complications can range from 5-40% and include bleeding, infection, and tracheal stenosis. Care involves constant supervision, regular suctioning and cleaning of the tracheostomy tube, humidification, dressing changes, and assessing for complications.
McKinley Plowman - Strategic Planning your Business for Maximum Success!McPlowman
This document discusses strategic planning and how it can help businesses grow profitably. It emphasizes developing a clear strategic plan with objectives and key performance indicators. An effective plan includes designing a vision and culture, understanding competitive advantages, and leveraging resources to increase business value and exit options. Government grants are also available to support business growth strategies.
Este documento trata sobre la contabilidad de costos. Explica que la contabilidad de costos tiene como objetivo controlar las operaciones productivas de una empresa a través del estudio y seguimiento de los costos. También define la contabilidad de costos como una técnica para medir y analizar los resultados internos de una empresa y ser una herramienta útil para la toma de decisiones. Finalmente, señala que la contabilidad de costos es importante para llevar un registro y control de los costos de producción de una empresa y establecer las correcciones necesari
Este documento presenta SymfonyZero, un proyecto de inicio gratuito para proyectos Symfony que incluye bundles configurados y funcionalidades comunes para agilizar el desarrollo. También presenta SymfonyZero-API, orientado a proyectos que usen Symfony como API REST. Ambos incluyen características como gestión de usuarios, panel de administración y documentación para facilitar el desarrollo rápido de proyectos Symfony.
This document outlines the steps taken to create a senior project picture slideshow, including multiple rough draft covers revised with advice from a project facilitator and teacher before a final cover was completed.
Este documento presenta un módulo sobre formulación estratégica de problemas. El objetivo es que los estudiantes desarrollen habilidades para analizar enunciados, identificar variables y relaciones, y responder interrogantes con base a datos y premisas. El módulo cubre temas como introducción a la solución de problemas, problemas de una y dos variables, eventos dinámicos y búsqueda exhaustiva.
Our presentation about the last P of 4Ps in Marketing Mix - Promotion. This includes 6 parts: tools in Promotion (Advertising, Public Relations, Sales Promotion, Personal Selling), Promotion and Social Media, The casy study
Chronic leukemia is a type of cancer that results in the overproduction of white blood cells. There are two main types: chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML). CLL involves an overgrowth of B lymphocytes, while CML affects granulocytes. Symptoms include fatigue, enlarged lymph nodes or spleen. Treatment involves chemotherapy, monoclonal antibodies, radiation therapy, or bone marrow transplantation depending on the type and stage of leukemia. Newer targeted therapies such as tyrosine kinase inhibitors have improved treatment of CML.
The document discusses repeat breeder syndrome in cows, which is defined as cows that have been bred 3 or more times but not conceived. It outlines various causes of fertilization failure and early embryonic death that can contribute to repeat breeding, including issues with ovulation, sperm and egg quality, uterine infections, nutrition deficiencies, and environmental stresses. Potential treatments discussed include hormones, antibiotics, addressing energy deficiencies, and improving management practices.
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Waves _______________________ (Name) How do ocea.docxmelbruce90096
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(Name)
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your answer.
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Wave “B” has a height of 4m and a wavelength of 6m.
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Figure 2. A grid for drawing a wave.
(5) What is the steepness of wave A that you sketched?
(6) Will wave A break?
(7) What is the steepness of wave B that you sketched?
(8) Will wave B break?
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LandslideTsunamisFRANCK
1. Initiating Factors and Physics of Landslide Tsunamis
Joshua S. Franck
Tsunamis are commonly referred to as shallow water waves that result from
seismic slip along a fault. Potential energy originates from stress along the fault
surface and is translated into wave energy. The incompressibility of water allows for
a majority of the energy to be translated into the wave crest. Resulting waves have
long wavelengths, on the order of 100 km, and propagate at high phase velocities, on
the order of 100 km/hr but with small initial amplitudes, usually only 1-5 m. These
ocean waves propagate radially outward in large bodies of water of varying depth
towards the shoreline, which results in waves slowing along the ocean floor.
Following the phase speed formula for shallow body waves, those where
wavelength (λ)>> Depth (H);
vphase = (g*H)0.5.
As waves enter shallower water, vphase decreases and as a result crest-amplitude
increases, which forms the large destructive waveforms which hit coastal regions.
Alternatively, Tsunamis can also be triggered when similar energy conditions
are appropriate. Firstly, an appropriately sized
body of water must be available for the wave to
propagate, and form a large enough wave crest.
In specific cases tsunamis can be generated in
bodies such as Lakes, Straits, Bays or
Reservoirs. Second, there must be an event of large initial energy to generate the
Figure 1
2. wave. In many cases this can result from Landslides (subaerial and subaqueous),
Volcanic eruptions or even Meteor impacts (cosmogenic)(Levin-Mikhail 2009). The
extent of this paper is limited to tsunamis generated in alternative water bodies by
landslides.
In two specific cases of landslide Tsunamis (LSTs), there is a dependence on
the initial impulse from the falling mass,
Lituya bay 1958, and by the water displaced
slide mass volume, Vajont reservoir 1963.
Note that either of these cases is not
primarily dependent on these two
illustrated factors but for the sake of
simplicity both cases will be analyzed as examples for these conditions.
As previously stated, LSTs are initiated by high-energy events, in this case landslides
where generally the volume of the slide ranges from 1-100 Mm3 (Crosta-
Imposimato 2013). These masses will range in elevation from orders of 10-100 m
above the waterline (Crosta-Imposimato 2013) and have densities from 2-3 g/cm3,
within range for rocks along a given coastal or lake shoreline (Twiss-Moores 1992).
Upon release, the slide mass can reach velocities of up to 110 m/s (Crosta-
Imposimato 2013). For example, a volume of 10^6 m3 of density 2 g/cm3 with a
frontal velocity of 50 m/s would have;
T=0.5*m*v2=0.5*ϱslide*Volslide*v2=0.5(2000kg/m3)(107m3)(20m/s)2
T=4*1012 J
Figure 2
3. As mass accumulates by either deposition or uplift (Twiss-Moores 1992), the
slope on which it adheres steepens (δ) and puts more stress (μ) on the lithological
boundaries which held the mass in place. The addition of mass results in greater
instability along the slope. In most cases instability is not the only factor to slide
events. In many examples of LSTs, slides are initiated by nearby seismic events, not
local enough to cause the Tsunami first hand but enough to generate a subsequent
slide. The most important note is that generally as potential energy increases,
instability increases proportionally.
Other factors, which can affect the instability of a material, are saturation of
the mass, usually after heavy rains, undercutting of material from heavy water flow
or nearby construction projects.
Slope failure can be most explained using the Safety Factor (SF) (Ritter
2004). SF is derived by first examining the force body diagram acting on the center
of mass of a body or slab of material, in this case consolidated slope material. Our
initial diagram (Figure 1) shows the normal stress of the material (σ), the
downward force on material acting on the slip surface, which is counteracted by the
pore pressure (μ). The materials position is maintained by the Shear strength of the
material (S), which is combination of forces opposing the shear stress (τ) that is
primarily composed of the cohesion of the material (C), and internal friction (at an
angle φ). Shear strength is given by the Coulomb equation;
Coulomb Equation: S=C+(σ-μ)tan(φ)
4. By representing the per/unit weight of the material as gamma and the height of
material as z, we can find the force of gravity (figure 2). From this we can define the
normal stress as;
σ=γ*z*cos(β)cos(β)
By adding additional material, in most cases water, but we can also assume
additional material (defined γw), we can represent the pore pressure;
μ=γ*m*z*cos(β)cos(β)
With m=Z/zw (zw=thickness added material). By this same notion shear stress is
represented by;
τ=γ*z*cos(β)sin(β)
With this notion, SF is then simply represented as the ratio of shear strength
over shear stress, SF=S/τ.
SF=S/τ=Shear Strength/Shear Stress
Where: 0<SF<∞
When SF=1, the slope is then determined to be balanced, but regarded as unsafe.
SF>1 is representative of stable slopes with larger values of SF correlating to more
stable conditions and. SF<1 is defined as slopes with instability. In cases where the
slope is unstable, is where slides occur.
Factors that could then reduce values of SF are γ*z=weight of overlying
material and the product of cos(β)sin(β), with beta being the angle of slip, with
cos(β)sin(β) increases to a maximum angle of β=π/4, where cos(β)=sin(β). This
makes sense as the angle of slide increases the value of Z will begin to approach
larger values, more simply, as β→π/2, z→∞. For the purpose of this paper we
5. assume SF≤1. The instance of SF=1 resulting in loss of stability is attributed to
seismic activity or other outside forces, leads to subsequent disturbances to
otherwise static material.
After losing stability the landmass moves as a super-viscous fluid along the
slope. The velocity field within the moving mass can then be interpreted as shearing
force acting along both the top and bottom of the moving material. We can then use
properties of moving viscous fluids (marked in notes) to estimate the velocity field
within the flow along the slope. Although the mass velocity gradient is interesting,
what is more important is the velocity of the flow front represented as an area h*z
with velocity vf. With this estimation we can then begin estimations as to the
strength of the impulse that initiates the Tsunami wave within the greater body.
One of the most notable values associated with the interactions between
slides and the resulting wave structures is the Froud number (F) (Fritz-Hager
2004). The Froud number is defined as;
F=vs/(g*D)0.5
Where: 0≤F≤∞
This value is also used in reference to the waves generated by a ship moving
through a liquid. Most notable in this function is the slide front to shallow water
phase velocity ratio, leading to relationship of F=1 corresponding to resonance
Figure 3
6. between the mass flow and the waveform. Simply put, if the slide is moving at the
same velocity of the resulting waveform, there is a significant increase in amplitude.
We will use the case of the Lituya landslide (1958) to illustrate the wave results
from an impulse, triggered from a nearby magnitude 7.7 earthquake 21 km away on
the Fairweather fault (Schwaiger-Higman 2007). The quake initiated the loss of 30
Mm3 from a mean elevation of 600 m above the water line which came rushing
down a 40° slope to an estimated max velocity of 110 m/s. The maximum thickness
of the slide was determined to be 92m, from comparing photographs before and
after the slide (figure 3), and the depth of the bay is considered to be 122m
(Schwaiger-Higman 2007). The first estimation that can be made is simply for the
Froud number for this interaction;
F=v/sqrt(g*D)=(110m/s)/(50m*10m/s2)0.5=4.9
From here we can already see that the situation is already close to resonance, within
a factor of 4, which partially explains such a large amplitude collision along the
adjacent shoreline (524m high!).
Through the use of a collision simulation between the waterline and the
viscous slide (Schwaiger-Higman 2007), it was determined that the resulting
waveform is more complex than a single radial wave. As is the case in many slides,
the overabundance of mass at high velocity induces turbulence, this is as expected if
we consider a high viscous flow interacting at low velocities. Examination of the
Reynolds number associated with the collision;
Re=L*v/η=(1Km)*(100m/s)/(1000kg/m3)=100
7. Where: 0≤Re<∞
From this we find solutions greater than 1 but still within
small values. Waves could be classified by their Froud
number (Fritz-Hager 2004) and separated into categories as
such;
F<(4-7.5S) where S=s/h nonlinear oscillatory (Note Figure4 with F vs. S)
(4-7.5S)≤F<(6.6-8S) nonlinear transition to Solitary waves
Froud numbers within these ranges are indicative of slides with high-energy slide
impact, resulting in oscillatory motion of fluid within the body. Froud values
representative of solitary waveforms vary within ranges of;
(6.6-8S)≤F<(8.2-8S) Solitary Waves
F≥(8.2-8S) Dissipative Bore
As far as the mechanics of the actual slide, they are discussed in Fritz’s paper
(Fritz-Hager 2004). The dimensions of the slide are estimated, from slide scarring,
with width and height 730 and 915m respectively and a maximum slide thickness of
92m, with a calculated volume of 30.6*106m3. Scale models depicting the slide event
(Figure 5, frames a-d) show the velocity vectors increasing around the shape of the
slide mass. Most notably in the first frames the velocity field is normal to mass the
front. Even in subsequent frames the velocity vectors from the first frames are still
oriented normal to the original slide geometry, even those where the fluid has lost
contact with the mass. In these cases the waveform is primarily influenced by the
front of the mass itself as it propagates through the fluid. In this case we refer back
to the previous mentioned potential energy and use it as a constraint for maximum
Figure 4
8. wave crest energy. Through the same modeling process (Fritz-Hager 2004), we can
estimate the loss of energy as the mass travels down slope. Using the kinetic energy
formula;
Es=0.5*ms*vs
2=4E12J
and using centroid velocity of the flow;
Vs=[2*g*Δz(1-f*cot(α)]0.5
Using this we can estimate the kinetic energy of the flow and compare to the original
potential, T=400 GJ;
U-T=600m*10m/s2*2000kg/m3-400GJ
ΔE=1.2E14J-4E11J=1.2E14J=0.997U
From this case we can see a loss of energy as the mass travels down-slope,
but only a small percentage. Here we have a representation of the multiple
regressions for the leading wave crest, as estimated in the Fritz paper which was
found experimentally and represented by the function;
Ac/h=0.25*(vs/sqrt(g*H))1.4*(s/h)0.8=0.25*F1.4*S0.8
Within the this value we can observe the relationship between the kinetic and wave
crest energy and their direct relation to the Froud number as well as the ratio of
slide thickness and collision depth and the slide volume over the product of slide
width to the square of the thickness. From the same experiment it was determined
that only 2-30% of the kinetic energy was transferred to the leading wave crest
(Fritz-Hager 2004).
9. The other extreme case would be that of the Vajont disaster of 1963. The
Vajont slide, similar to that of the Lituya event, displaced an area of 2 km^2 and an
estimated 275 Mm3 (Crosta-
Imposimato 2013). The mass
traveled down-slope at an angle of
17° to a maximum frontal velocity
of 20-30 m/s. The large volume
completely displaced the reservoir,
which at that point was about two
thirds full (115 Mm3 with an
average depth of H=100m). The
relative slide volume vs. reservoir
volume makes any sort of wave
structure, as previously illustrated
in the Lituya example, not viable. In
this case we neglect viscosity
altogether and treat the landslide
as a sliding block with an estimated
Froud number ranging between 0.26 and 0.75.
The result from the collision of the block into the reservoir sent water 140 m
up the opposing flank and 235m above the reservoir level and 100 m over the height
of the dam. The wave continued down the valley and towards the villages of
Figure 5
10. Longarone, Pirago, Rivalta, Villanova and Fae. The surge resulted in the deaths of
2000 people and transformed the valley into a muddy swamp.
Unlike the example of Lituya Bay, the slide did not result from an initial
seismic event, but by the loss of stability most likely due to lithologic boundaries
between stratigraphy, as seen in the geologic cross section in figure (Figure 6). This
difference would cause the cohesion to be much smaller than that of a homogenous
material. With loss of cohesion we can re-evaluate our Safety Factor for the slide.
Recall our safety factor represents the ratio of shear strength over shear stress. With
an already large amount of mass along the top of the boundary and a lowered
cohesion we can easily estimate a safety factor less than one. This example
illustrates the importance of evaluating civil engineering projects and possible
disasters that could result from their placement, relative to local geography.
After the collision the wave was estimated to undergo a series of oscillations
within the now altered reservoir
basin, raised significantly by the
slide. These oscillations are difficult
to understand as they did little to
erode the surrounding exposed
material, leaving scouring along the
shoreline. The subsequent wave had
significantly less amplitude then that
of the initial waveform, as a majority
of the water had already been displaced over the dam (Crosta-Imposimato 2013).
Figure 6
11. In both the cases of Lituya bay and the Vajont reservoir disaster slides where
most influenced by the high risen, steep slopes of material which had either a SF
value less then one or were triggered by an excess amount of energy, like that of the
Fairweather fault slip in Lituya bay. In most cases the volume of the slide is on the
same order of magnitude of that of the body of water it is interacting with, and in
some cases significantly greater. Slides that are significantly larger then the water
bodies they penetrate, like that of the Vajont disaster, are more importantly
characterized by the large volume of water displacement rather then resulting
waveforms. In these cases violent high-energy fluid is sent down geographic
gradients, which can lead to catastrophic results to any structures along the floods
path. In other cases the slide mass geometry most influences the waveform, taking
advantage of waters incompressibility. The mass displaces fluid normal to the slide
surface, accelerating the wave crest, transferring kinetic energy of the slide into
wave crest amplitude, shown in change of velocity vectors between frames through
experimentation (Schwaiger-Higman 2007).
With the primary factors for LSTs in mind, it is possible to assess high-risk
areas within California. Along the shoreline within most bays/inlets, there is high
damage potential especially that of the San Francisco bay area. Low depth values
within the bay present the potential for large Froud values which even further
represent a risk for Tsunami damage. Although the bay area is not at risk due to a
lack of high rising slopes above one hundred meters above the waterline or within
close enough proximity for high velocity mass to reach the water before energy is
dissipated due to friction along the slide pathway. Another high-risk region would
12. be the eastern banks of Lake Tahoe. The slopes reach up to 400 m above the
waterline with slopes leading directly into the lake. This creates the potential for
large volumes of high velocity material to make contact with the fluid and instigate a
waveform such as in Lituya bay. In this case though the surface area of the lake is
substantial and provides a large region for the wave to propagate. As seen in the
damage following the Lituya tsunami, the wave amplitude was largest when
powered by the motion of the landslide along the lake bottom. In this case the slide
would come to rest after some several hundred meters, allowing the wave to
dissipate radially throughout the lake surface.
One example that presents a significant danger is that of a possible event in
Trinity Lake, located 46 km Northwest of Redding Ca. The lake is a man-made
reservoir, which is one of the largest in California. The lake itself is composed of
several inlets that were previously gorges between nearby mountains. In some
cases the slopes rise up several hundred meters above the water column and lead
directly to the lake surface. Furthermore some of the steepest slopes which hold the
highest slide potential are those which are only one kilometer away from the man
made dam. The possibility of a waveform such as the one Lituya bay, overriding the
dam and traveling down towards Lewton Lake and Lewton itself, as happened in
Vajont, is very likely. Considering the seismic activity in California due to contact
between the North American and Pacific Plate, including that of the San Andreas
Fault, it is more likely that even slopes with SF>1 to be triggered by additional
energy from ground waves from large magnitude earthquakes.
13. Works Cited
Levin, Boris, and Mikhail Nosov. "Physics of Tsunami Formation by Sources of
Nonseismic Origin." Physics of Tsunamis. Dordrecht: Springer, 2009. Print.
Fritz, H. M., W. H. Hager, and H.-E. Minor. "Near Field Characteristics of Landslide
Generated Impulse Waves." Journal of Waterway, Port, Coastal, and Ocean
Engineering (2004): 287-300. ASCE Library. American Society of Civil Engineers.
Mon. 1 Dec. 2014. www.ascelibrary.or
Jiang, L., and P. H. Leblond. "The Coupling of A Submarine Slide and The Surface
Waves Which It Generates." Journal of Geophysical Research (1999): 12731-
2744. Wiley Online Library. John Wiley & Sons, Inc. Mon. 1 Dec. 2014.
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