Dynamic soil-structure interaction using disturbed state concept and artificial neural networks for parameter evaluation

Persistent Link:
http://hdl.handle.net/10150/289773
Title:
Dynamic soil-structure interaction using disturbed state concept and artificial neural networks for parameter evaluation
Author:
Pradhan, Shashank
Issue Date:
2002
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Interaction between the superstructure and foundation depends on the behavior of soil supporting the foundation. To study the behavior of interfaces, it is necessary to characterize the behavior at the interface, model constitutive relationships mathematically, and incorporate the model together with the governing equations of mechanics into numerical procedures such as the finite element method. Such an approach then can be used for solving complex problems that involve dynamic loading, nonlinear material behavior, and the presence of water, leading to saturated interfaces. In this dissertation, a general model, called the Disturbed State Concept constitutive model has been developed to model saturated Ottawa sand-Concrete interface and saturated Nevada sand. In the DSC, the material is assumed to transform continuously from the relative intact state to the fully adjusted state under loading. Hence the observed response of the material is expressed in terms of response of relatively intact and fully adjusted states. The DSC model is a unified approach and allows for elastic and plastic strains, damage, and softening and stiffening. The model parameters for saturated Ottawa sand-Concrete interface and saturated Nevada sand are evaluated using data from laboratory tests and are used for the verification of DSC model. The model predictions showed satisfactory correlation with the test results. In this dissertation, a new program based on concept of neural computing is developed to facilitate determination of interface parameters when no test data is available. The back propagation training algorithm with bias nodes is used to train the network. The program is developed in FORTRAN language using Microsoft Developer Studio. The reason for selecting FORTRAN as a programming language to develop Biased Artificial Neural Network (BANN) simulator is due to its proficiency in number crunching operations which is the core requirement of the ANN. A nonlinear dynamic finite element program (DSC-DYN2D) based on the DSC model is used to solve two problems, a centrifuge test and an axially loaded pile involving interface behavior. Overall, it can be stated that the DSC model allows realistic simulation of complex dynamic soil-structure interaction problems, and is capable of characterizing behavior of saturated interfaces involving liquefaction under dynamic and earthquake loading.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering, Civil.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Civil Engineering and Engineering Mechanics
Degree Grantor:
University of Arizona
Advisor:
Desai, Chandrakant S.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDynamic soil-structure interaction using disturbed state concept and artificial neural networks for parameter evaluationen_US
dc.creatorPradhan, Shashanken_US
dc.contributor.authorPradhan, Shashanken_US
dc.date.issued2002en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractInteraction between the superstructure and foundation depends on the behavior of soil supporting the foundation. To study the behavior of interfaces, it is necessary to characterize the behavior at the interface, model constitutive relationships mathematically, and incorporate the model together with the governing equations of mechanics into numerical procedures such as the finite element method. Such an approach then can be used for solving complex problems that involve dynamic loading, nonlinear material behavior, and the presence of water, leading to saturated interfaces. In this dissertation, a general model, called the Disturbed State Concept constitutive model has been developed to model saturated Ottawa sand-Concrete interface and saturated Nevada sand. In the DSC, the material is assumed to transform continuously from the relative intact state to the fully adjusted state under loading. Hence the observed response of the material is expressed in terms of response of relatively intact and fully adjusted states. The DSC model is a unified approach and allows for elastic and plastic strains, damage, and softening and stiffening. The model parameters for saturated Ottawa sand-Concrete interface and saturated Nevada sand are evaluated using data from laboratory tests and are used for the verification of DSC model. The model predictions showed satisfactory correlation with the test results. In this dissertation, a new program based on concept of neural computing is developed to facilitate determination of interface parameters when no test data is available. The back propagation training algorithm with bias nodes is used to train the network. The program is developed in FORTRAN language using Microsoft Developer Studio. The reason for selecting FORTRAN as a programming language to develop Biased Artificial Neural Network (BANN) simulator is due to its proficiency in number crunching operations which is the core requirement of the ANN. A nonlinear dynamic finite element program (DSC-DYN2D) based on the DSC model is used to solve two problems, a centrifuge test and an axially loaded pile involving interface behavior. Overall, it can be stated that the DSC model allows realistic simulation of complex dynamic soil-structure interaction problems, and is capable of characterizing behavior of saturated interfaces involving liquefaction under dynamic and earthquake loading.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineering, Civil.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineCivil Engineering and Engineering Mechanicsen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorDesai, Chandrakant S.en_US
dc.identifier.proquest3050297en_US
dc.identifier.bibrecord.b42723735en_US
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