Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

The paper describes an approach for qualifying soil-structure systems behavior, using simple numeric models – “geotoys”, reflecting the main features of the systems behavior and enabling numeric simulation of various case histories. Three case histories of major karstic sinkholes are analyzed to show that man-made structures above a karstic cavity prevent formation sinkhole. When plastic zones reach the structure periphery, the soil-structure system becomes unstable. Prior settlements could be negligible to serve as precursors. Another soil-footing-superstructure (SFSS) model is a 2D geotoy - an exact mathematical solution, used for multiple simulations (about 10,000) of SFSS sensitivity i.e., response to input parameters variations. The sensitivity was rated for each input-output pair [1]. The most interesting findings are the following: 1) SFSS stress state is very sensitive to soil strength parameters c and φ, which are responsible for formation of soil disruption zones (‘plastic zone’) under footing edges. 2) If a structure rests on a homogeneous soil base then it is practically insensitive to soil base compressibility i.e., soil modulus E variations. 3) 3D FEM analysis confirmed that 2D simulations can be used for qualitative SFSS analysis. 4) Geotoys can be used for case histories analysis, risk assessment, training practical intuition, education purposes and international exchange and cooperation.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Application of Simplified Models to Qualitative Geotechnical Analysis

Arlington, Virginia

The paper describes an approach for qualifying soil-structure systems behavior, using simple numeric models – “geotoys”, reflecting the main features of the systems behavior and enabling numeric simulation of various case histories. Three case histories of major karstic sinkholes are analyzed to show that man-made structures above a karstic cavity prevent formation sinkhole. When plastic zones reach the structure periphery, the soil-structure system becomes unstable. Prior settlements could be negligible to serve as precursors. Another soil-footing-superstructure (SFSS) model is a 2D geotoy - an exact mathematical solution, used for multiple simulations (about 10,000) of SFSS sensitivity i.e., response to input parameters variations. The sensitivity was rated for each input-output pair [1]. The most interesting findings are the following: 1) SFSS stress state is very sensitive to soil strength parameters c and φ, which are responsible for formation of soil disruption zones (‘plastic zone’) under footing edges. 2) If a structure rests on a homogeneous soil base then it is practically insensitive to soil base compressibility i.e., soil modulus E variations. 3) 3D FEM analysis confirmed that 2D simulations can be used for qualitative SFSS analysis. 4) Geotoys can be used for case histories analysis, risk assessment, training practical intuition, education purposes and international exchange and cooperation.