Linear vs. Non-linear: Difference between revisions
Rmanwaring (talk | contribs) (Created page with "<!-- Delete any sections that are not necessary to your topic. Add pictures/sections as needed --> __NOTOC__ <!-- Add Category to drive breadcrumb menus --> Category: Global Stability of a Dam {| align="right" style="width:10%;" cellpadding="7" | 350px|x350px|link=https://damfailures.org/lessons-learned/concrete-gravity-dams-should-be-evaluated-to-accommodate-full-uplift/ |- |style="text-align:center; font-size:90%;"| Learn more...") |
Rmanwaring (talk | contribs) No edit summary |
||
| Line 13: | Line 13: | ||
<!-- Introductory paragraph or topic page summary --> | <!-- Introductory paragraph or topic page summary --> | ||
"Both new and existing structures are constantly being examined to determine if they meet [[stability]] criteria. The traditional procedure is to evaluate sliding stability of these structures using the limit equilibrium method of analysis and to evaluate rotational stability using rigid body assumptions and bearing pressure distributions that vary linearly across the base. Soil and uplift loads on the structure are often based on simplifying assumptions. In the limit equilibrium method, only the stress at failure is considered, usually as represented by the Mohr-Coulomb limit-state criterion. The simplified loads and the Mohr-Coulomb limit-state criterion are then used to obtain a single overall factor of safety against a sliding stability failure. This traditional approach is appropriate for many structures where it is difficult to predict just how a particular failure [[mechanism]] may develop. However, for existing structures where more is known about service state conditions and uplift pressures, it is possible to more precisely predict what stress changes must occur to develop a failure condition. The margin of safety can be more accurately determined when the path to failure, from initial stress conditions to limit state conditions, is known. This path to failure can be investigated using linear elastic and nonlinear finite-element numerical solutions and facture mechanics concepts. Because the deformation of the structure and its foundation is considered in finite element analyses, and because the path to failure can be more realistically characterized through facture mechanics, a more accurate assessment of safety can often be made using advanced analytical methods."<ref name="EM 1110-2-2100">[[Stability of Concrete Structures (EM 1110-2-2100) | Stability of Concrete Structures (EM 1110-2-2100), USACE, 2005]]</ref> | "Both new and existing structures are constantly being examined to determine if they meet [[stability]] criteria. The traditional procedure is to evaluate [[Sliding Stability|sliding stability]] of these structures using the limit equilibrium method of analysis and to evaluate [[Rotational Stability|rotational stability]] using rigid body assumptions and bearing pressure distributions that vary linearly across the base. Soil and uplift loads on the structure are often based on simplifying assumptions. In the limit equilibrium method, only the stress at failure is considered, usually as represented by the Mohr-Coulomb limit-state criterion. The simplified loads and the Mohr-Coulomb limit-state criterion are then used to obtain a single overall factor of safety against a sliding stability failure. This traditional approach is appropriate for many structures where it is difficult to predict just how a particular failure [[mechanism]] may develop. However, for existing structures where more is known about service state conditions and uplift pressures, it is possible to more precisely predict what stress changes must occur to develop a failure condition. The margin of safety can be more accurately determined when the path to failure, from initial stress conditions to limit state conditions, is known. This path to failure can be investigated using linear elastic and nonlinear finite-element numerical solutions and facture mechanics concepts. Because the deformation of the structure and its foundation is considered in finite element analyses, and because the path to failure can be more realistically characterized through facture mechanics, a more accurate assessment of safety can often be made using advanced analytical methods."<ref name="EM 1110-2-2100">[[Stability of Concrete Structures (EM 1110-2-2100) | Stability of Concrete Structures (EM 1110-2-2100), USACE, 2005]]</ref> | ||
==[[Best Practices Resources]]== | ==[[Best Practices Resources]]== | ||
{{Document Icon}} [[Stability of Concrete Structures (EM 1110-2-2100) | Stability of Concrete Structures (EM 1110-2-2100), USACE, 2005]] | {{Document Icon}} [[Stability of Concrete Structures (EM 1110-2-2100) | Stability of Concrete Structures (EM 1110-2-2100), USACE, 2005]] | ||
{{Document Icon}} [[Evaluation and Comparison of Stability Analysis and Uplift Criteria for Concrete Gravity Dams by Three Federal Agencies (ERDC/ITL TR-00-1) | Evaluation and Comparison of Stability Analysis and Uplift Criteria for Concrete Gravity Dams by Three Federal Agencies (ERDC/ITL TR-00-1), USACE, 2000]] | |||
{{Document Icon}} [[Gravity Dam Design (EM 1110-2-2200) | Gravity Dam Design (EM 1110-2-2200), USACE, 1995]] | |||
{{Document Icon}} [[Arch Dam Design (EM 1110-2-2201) | Arch Dam Design (EM 1110-2-2201), USACE, 1994]] | |||
{{Document Icon}} [[Design of Small Dams | Design of Small Dams, USBR, 1987]] | |||
==[[Trainings]]== | ==[[Trainings]]== | ||
Revision as of 23:55, 29 November 2022
|
| Learn more about the need to consider uplift pressure when designing a gravity structure at DamFailures.org |
"Both new and existing structures are constantly being examined to determine if they meet stability criteria. The traditional procedure is to evaluate sliding stability of these structures using the limit equilibrium method of analysis and to evaluate rotational stability using rigid body assumptions and bearing pressure distributions that vary linearly across the base. Soil and uplift loads on the structure are often based on simplifying assumptions. In the limit equilibrium method, only the stress at failure is considered, usually as represented by the Mohr-Coulomb limit-state criterion. The simplified loads and the Mohr-Coulomb limit-state criterion are then used to obtain a single overall factor of safety against a sliding stability failure. This traditional approach is appropriate for many structures where it is difficult to predict just how a particular failure mechanism may develop. However, for existing structures where more is known about service state conditions and uplift pressures, it is possible to more precisely predict what stress changes must occur to develop a failure condition. The margin of safety can be more accurately determined when the path to failure, from initial stress conditions to limit state conditions, is known. This path to failure can be investigated using linear elastic and nonlinear finite-element numerical solutions and facture mechanics concepts. Because the deformation of the structure and its foundation is considered in finite element analyses, and because the path to failure can be more realistically characterized through facture mechanics, a more accurate assessment of safety can often be made using advanced analytical methods."[1]
Best Practices Resources
Stability of Concrete Structures (EM 1110-2-2100), USACE, 2005
Gravity Dam Design (EM 1110-2-2200), USACE, 1995
Arch Dam Design (EM 1110-2-2201), USACE, 1994
Design of Small Dams, USBR, 1987
Trainings
On-Demand Webinar: Stability Evaluations of Concrete Dams
On-Demand Webinar: Analysis of Concrete Arch Dams
Citations:
Revision ID: 4631
Revision Date: 11/29/2022