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An Investigation Into Dynamic Normal Vertical Effective Stresses Induced by Horizontal Shaking.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	An Investigation Into Dynamic Normal Vertical Effective Stresses Induced by Horizontal Shaking./
Author:	Westcott, Joelle.
Description:	1 online resource (111 pages)
Notes:	Source: Masters Abstracts International, Volume: 84-12.
Contained By:	Masters Abstracts International84-12.
Subject:	Civil engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9798379695743

An Investigation Into Dynamic Normal Vertical Effective Stresses Induced by Horizontal Shaking.
Westcott, Joelle.

An Investigation Into Dynamic Normal Vertical Effective Stresses Induced by Horizontal Shaking. - 1 online resource (111 pages)

Source: Masters Abstracts International, Volume: 84-12.

Thesis (M.S.)--University of Colorado at Boulder, 2023.

Includes bibliographical references

Retaining wall design has been historically dominated by the use of dynamic earth pressure coefficients to obtain the normal dynamic horizontal forces acting on the wall from the soil. However, the use of dynamic earth pressure coefficients has been shown to both overestimate and underestimate the normal dynamic horizontal effective stresses implied. These inaccuracies result in an over or under-designed structure, which is either resourcefully wasteful or unsafe. This study investigates the scope to move away from historically used dynamic earth pressure coefficients. Centrifuge and numerical modeling are used to understand the fundamental dynamic soil response and highlight the importance of rocking of the retained soil. The case of a horizontal input motion inducing rocking into a soil body with reduced shear strength at its boundaries is considered. The occurrence of rocking is confirmed both experimentally and numerically, e.g., with measured and predicted out-of-phase vertical accelerations and dynamic displacement components. Crucially, the observed soil rocking also induces dynamically varying normal vertical effective stresses. The dynamic vertical effective stresses impact the limiting and mobilized dynamic horizontal effective stresses, demonstrated by both the experimental and numerical time histories and distributions. This is relevant to the dynamic horizontal forces that soil retaining systems can attract.Careful examination of the dynamic earth pressure coefficient time histories (K(t)) reveals that dynamic earth pressure coefficients derived from simplified pseudo-static limit states, e.g., from the M-O method, are exceeded. However, the 'static' earth pressure coefficients, Ka and Kp, are sufficient to bound the limiting dynamic stress states. Accounting for the dynamic normal vertical effective stress allows for a simpler interpretation of dynamic earth pressures and thus will inform future design for soil-structure interaction problems.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798379695743Subjects--Topical Terms:

561339
Civil engineering.
Subjects--Index Terms:

Centrifuge modelingIndex Terms--Genre/Form:

554714
Electronic books.

An Investigation Into Dynamic Normal Vertical Effective Stresses Induced by Horizontal Shaking.
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500 $a Source: Masters Abstracts International, Volume: 84-12.
500 $a Advisor: Madabhushi, Srikanth S. C.
502 $a Thesis (M.S.)--University of Colorado at Boulder, 2023.
504 $a Includes bibliographical references
520 $a Retaining wall design has been historically dominated by the use of dynamic earth pressure coefficients to obtain the normal dynamic horizontal forces acting on the wall from the soil. However, the use of dynamic earth pressure coefficients has been shown to both overestimate and underestimate the normal dynamic horizontal effective stresses implied. These inaccuracies result in an over or under-designed structure, which is either resourcefully wasteful or unsafe. This study investigates the scope to move away from historically used dynamic earth pressure coefficients. Centrifuge and numerical modeling are used to understand the fundamental dynamic soil response and highlight the importance of rocking of the retained soil. The case of a horizontal input motion inducing rocking into a soil body with reduced shear strength at its boundaries is considered. The occurrence of rocking is confirmed both experimentally and numerically, e.g., with measured and predicted out-of-phase vertical accelerations and dynamic displacement components. Crucially, the observed soil rocking also induces dynamically varying normal vertical effective stresses. The dynamic vertical effective stresses impact the limiting and mobilized dynamic horizontal effective stresses, demonstrated by both the experimental and numerical time histories and distributions. This is relevant to the dynamic horizontal forces that soil retaining systems can attract.Careful examination of the dynamic earth pressure coefficient time histories (K(t)) reveals that dynamic earth pressure coefficients derived from simplified pseudo-static limit states, e.g., from the M-O method, are exceeded. However, the 'static' earth pressure coefficients, Ka and Kp, are sufficient to bound the limiting dynamic stress states. Accounting for the dynamic normal vertical effective stress allows for a simpler interpretation of dynamic earth pressures and thus will inform future design for soil-structure interaction problems.
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538 $a Mode of access: World Wide Web
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650 4 $a Geological engineering. $3 1186227
653 $a Centrifuge modeling
653 $a Earth pressures
653 $a Earthquake engineering
653 $a Finite element modelling
653 $a Retaining walls
653 $a Soil structure interaction
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