Thesis (M.S. in civil engineering)--Washington State University, December 2005. / Includes bibliographical references.

Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007. / Dr. J. David Frost, Committee Chair ; Dr. G. Wayne Clough, Committee Co-Chair ; Dr. William F. Marcuson III, Committee Member ; Dr. Paul W. Mayne, Committee Member ; Dr. Susan Burns, Committee Member.

Urbanisation will require significant expansion of underground infrastructure, which results in unavoidable ground displacements that affect the built environment. Predicting the interaction between a tunnel, the soil and existing structures remains an engineering challenge due to the highly non-linear behaviour of both the soil and the building. This thesis investigates the interaction between a surface structure and tunnelling-induced ground displacements. Specifically, novel three-dimensionally printed building models with brittle material behaviour, similar to masonry, were developed and tested in a geotechnical centrifuge. This enabled replication of building models with representative global stiffness values and realistic building features including strip footings, intermediate walls, a rough soil-structure interface, building layouts and façade openings. By varying building characteristics, the impact of structural features on both the soil and building response to tunnelling in dense sand was investigated. Results illustrate that the presence of surface structures considerably altered the tunnelling-induced soil response. The building-to-tunnel position notably influences the magnitude of soil displacements and causes localised phenomena such as embedment of building corners. An increase of the façade opening area and building length reduces the alteration of the theoretical greenfield settlements, in particular the trough width. Moreover, the impact of varying the building layout is discussed in detail. For several building-tunnel scenarios, building distortions are quantified and the crucial role of building features is demonstrated. Structures spanning the greenfield inflection point experienced more deformation than identical structures positioned in either sagging or hogging, and partitioning a structure either side of the greenfield inflection point is shown to lead to unconservative damage assessments. Results also quantify the significant extent to which structural distortions increase as façade openings and building length increases. Observed building damage and cracking patterns confirm the reported trends. The experimental results are used to evaluate the performance of available methods to assess the behaviour of buildings to tunnelling. Predictions ignoring soil-structure interaction are usually overly conservative, while approaches based on the relative stiffness of a structure and the soil result in inconsistent predictions, though some methods performed better than others. Practical improvements to consider structural details when assessing this tunnel-soil-structure system are finally proposed.

Les travaux effectués dans le cadre de cette thèse portent sur la modélisation physique etnumérique du comportement des fondations superficielles sous sollicitations transverses dynamiques.Deux nouveaux modèles physiques sont développés.Le premier, en chambre d’étalonnage permet de réaliser des expériences sur modèle réduitd’une fondation superficielle encastrée dans un sable sec en respectant les conditions de confinementréelles. Des adaptations prototypes sont spécialement conçues pour permettre unchargement horizontal rapide, le couplage chargement vertical-horizontal, ainsi qu’un libremouvement de la fondation. L’influence des différents paramètres (densité du sable, amplitudedu déplacement horizontal et de la charge verticale, pressurisation du massif) est miseen évidence sur le comportement de la fondation.Le second porte sur l’interaction sol renforcé-fondation superficielle dans une " VisuCuve "de visualisation latérale du comportement. Il est mené sur une argile molle renforcée soit parun système de Colonnes à Module Mixte (CMM) soit par un système d’Inclusions Rigides etmatelas granulaire (IR). Ces modèles physiques en 2D sont soumis à des chargements horizontauxcycliques en quasi-statique et en dynamique pour l’étude de l’effet inertiel. L’efficacitécomparée des systèmes en termes de dissipation d’énergie est présentée.Une modélisation numérique des systèmes CMM et IR correspondant à la configuration expérimentaleet en vraie grandeur est développée à l’aide du logiciel FLAC3D. Les résultatsnumériques nous permettent de confirmer partiellement des tendances constatées lors des expériences.Les calculs des ouvrages en vraie grandeur permettent d’étudier plus précisémentla dissipation d’énergie par le calcul des coefficients d’amortissement dans les différents systèmes.L’effet inertiel et l’effet de la hauteur de la partie supérieure en gravier sont égalementdémontrés par les efforts internes calculés dans les inclusions. / The main issues of this work concern the physical and numerical modeling of the response ofa shallow foundation under dynamic horizontal loadings.Two novative physical modeling were performed.The first one uses a calibration chamber to carry out tests on a model of shallow foundationembedded in a dry sand, simulating the field confining conditions. A new experimental setup isbuilt up in order to allow the foundation movement under the coupling of vertical and dynamichorizontal loading. The effect of the different parameters on the foundation behavior (sanddensity, horizontal and vertical loading amplitude, pressure on the sand bulk) is presented.The second one concerns the interaction between a shallow foundation and a reinforced soil,consisting in soft clay reinforced either by a Mixed Module Columns (MMC) system or aRigid Inclusions (RI) system. The 2D physical models subjected to quasi-static and dynamichorizontal cyclic loadings are set up in the "VisuCuve" of the laboratory to study the inertialeffect by lateral visualization of the behavior. The energy dissipation efficiency between theMMC system and the RI system is compared.The numerical modeling of the experiments and the full scale MMC and RI systems areperformed with FLAC3D. In spite of some differences, the 2D numerical results show generallythe same tendencies with the experimental ones. The damping ratios calculated in the fullscale modeling lead to the more accurate energy dissipation analyses. The inertial effect andthe influence of the upper gravel part height are also displayed in terms of the internal forces.

Ce travail détaille une approche de calcul pour la résolution de problèmes dynamiques qui combinent des discrétisations en temps et dans le domaine de Laplace reposant sur une technique de sous-structuration. En particulier, la méthode développée cherche à remplir le besoin industriel de réaliser des calculs dynamiques tridimensionnels pour le risque sismique en prenant en compte des effets non-linéaires d'interaction sol-structure (ISS). Deux sous-domaines sont considérés dans ce problème. D'une part, le domaine de sol linéaire et non-borné qui est modélisé par une impédance de bord discrétisée dans le domaine de Laplace au moyen d'une méthode d'éléments de frontière ; et, de l'autre part, la superstructure qui fait référence pas seulement à la structure et sa fondation mais aussi, éventuellement, à une partie du sol présentant un comportement non-linéaire. Ce dernier sous-domaine est formulé dans le domaine temporel et discrétisé avec la méthode des éléments finis (FE). Dans ce cadre, les forces liées à l'ISS s'écrivent sous la forme d'une intégrale de convolution en temps dont le noyau est la transformée de Laplace inverse de la matrice d'impédance de sol. Pour pouvoir évaluer cette convolution dans le domaine temporel à partir d'une impédance de sol définie dans le domaine de Laplace, une approche basée sur des Quadratures de Convolution (QC) est présentée : la méthode hybride Laplace-Temps (L-T). La stabilité numérique de son couplage avec un schéma d'intégration de type Newmark est ensuite étudiée sur plusieurs modèles d'ISS en dynamique linéaire et non-linéaire. Finalement, la méthode L-T est testée sur un modèle numérique plus complexe, proche d'une application sismique de caractère industriel, et des résultats satisfaisants sont obtenus par rapport aux solutions de référence. / The present work addresses a computational methodology to solve dynamic problems coupling time and Laplace domain discretizations within a domain decomposition approach. In particular, the proposed methodology aims at meeting the industrial need of performing more accurate seismic risk assessments by accounting for three-dimensional dynamic soil-structure interaction (DSSI) in nonlinear analysis. Two subdomains are considered in this problem. On the one hand, the linear and unbounded domain of soil which is modelled by an impedance operator computed in the Laplace domain using a Boundary Element (BE) method; and, on the other hand, the superstructure which refers not only to the structure and its foundations but also to a region of soil that possibly exhibits nonlinear behaviour. The latter subdomain is formulated in the time domain and discretized using a Finite Element (FE) method. In this framework, the DSSI forces are expressed as a time convolution integral whose kernel is the inverse Laplace transform of the soil impedance matrix. In order to evaluate this convolution in the time domain by means of the soil impedance matrix (available in the Laplace domain), a Convolution Quadrature-based approach called the Hybrid Laplace-Time domain Approach (HLTA), is thus introduced. Its numerical stability when coupled to Newmark time integration schemes is subsequently investigated through several numerical examples of DSSI applications in linear and nonlinear analyses. The HLTA is finally tested on a more complex numerical model, closer to that of an industrial seismic application, and good results are obtained when compared to the reference solutions.

Master of Science / Department of Civil Engineering / Dunja Peric / Integral Abutment Bridges (IABs) are Jointless Bridges whereby the deck is continuous and monolithic with abutment walls. IABs are outperforming their non-integral counterparts in economy and safety. Their principal advantages are derived from the absence of expansion joints and sliding bearings in the deck, making them the most cost-effective system in terms of construction, maintenance, and longevity. The main purpose of constructing IABs is to prevent the corrosion of structure due to water seepage through joints. The simple and rapid construction provides smooth, uninterrupted deck that is aesthetically pleasing and safer for riding. The single structural unit increases the degree of redundancy enabling higher resistance to extreme events. However, the design of IABs not being an exact science poses certain critical issues. The continuity achieved by this construction results in thermally induced deformations. These in turn introduce a significantly complex and nonlinear soil-structure interaction into the response of abutment walls and piles of the IAB. The unknown soil response and its effect on the stresses in the bridge, creates uncertainties in the design. To gain a better understanding of the mechanism of load transfer due to thermal expansion, which is also dependent on the type of the soil adjacent to the abutment walls and piles, a 3D finite element analysis is carried out on a representative IAB using state-of-the-art finite element code ABAQUS/Standard 6.5-1. A literature review focusing on past numerical models of IABs is presented followed by details of the numerical model developed in this study using the interactive environment ABAQUS/CAE 6.5-1 along with the analysis details. A discussion of results for the analysis of the IAB with three different soil conditions and each experiencing three different temperature change scenarios is presented. Conclusions of the study and recommendations for future research wrap up the thesis. The advancement of knowledge enabled by this research will provide a basis for introduction of new guidelines in Kansas Bridge Design Manual.

No description available.

Uma solução computacional geral e expansível de análise da interação estrutura-maciço de solos foi desenvolvida adotando metodologia orientada a objetos. A técnica computacional apresenta um menu de retaguarda que torna a manipulação dos dados de entrada e os processos computacionais mais criteriosos e seguros. Os materiais possuem comportamento perfeitamente elástico-linear, enquanto o mecanismo de transferência de carga estrutura-solo é não linear. O maciço de solos é modelado através de dados de sondagens SPT e mapeamento geotécnico. A fundação é discretizada verticalmente para se obter as matrizes de flexibilidade da estrutura de fundação (MFEF) e do maciço de solos (MFMS). O processo interativo básico consiste em obter o vetor de recalques nos apoios pelo produto do vetor de cargas verticais com as matrizes MFEF e MFMS. Na seqüência, calcula-se o vetor de redistribuição de cargas pelo produto do vetor de recalques com a matriz de rigidez da superestrutura (MRS). Um procedimento iterativo condiciona a convergência de recalques e cargas verticais nos apoios. A solução foi utilizada para analisar o comportamento de edifícios de diferentes geometrias em planta e espacial, variando o perfil geotécnico do maciço suporte e a técnica de execução da estrutura de fundação. / A general and expansible computational code based in the oriented to object programming technique was developed aiming the soil-structure interaction analysis. This computational technique has a special feature that makes the data input operations and the computer processing safer and more criterious. This model considers that all materials behaves as perfectly linear elastic materials, although the soilstructure transfer mechanism is of non-linear nature. The soil mass compressibility and resistance are modelled from soil data obtained from geotechnical mapping techniques and SPT boreholes data. The flexibility matrix (MFEF) of the structural foundation elements and the flexibility matrix (MFMS) of soil mass elements are obtained through a numerical discretization procedure. The basic interative process consists in the calculation of the supports displacement vectors obtained by the multiplication of the vertical load vector by the MFEF and the MFMS matrix. Finally, the load redistribution is obtained by the multiplication of the displacement vector by the structural rigidity matrix (MRS). The uniqueness of the solution is guaranteed by the convergence of the displacements and vertical supports reactions by using an iterative procedure. This computational code was applied to the analysis of the behaviour of spatial framed buildings with varied geometry, taking into account different geotechnical soil conditions and different types of foundations.

A parametric study of single-span integral abutment bridge (IAB) was conducted using finite element analysis to explore the effects of various load conditions, bridge geometries, and soil properties. This study investigated the difference between the live load distribution of traditional jointed bridges and integral abutment bridges (IABs) under HL-93 truck component load. The results showed that AASHTO live load distribution factors (LLDFs) were overly conservative by up to 50% to use for IABs. LLDFs for IABs proposed by Dicleli and Erhan (2008) matched well for interior girder moment, but they were unconservative for exterior girder moment by up to 20% for the bridges studied. The study further investigated the effects of various parameters on the IAB responses under dead, live, and thermal loads and load combinations specified by AASHTO. The results of this study are limited to short to moderate single-span straight bridges under dead, live, and thermal loads. Due to a fixity of superstructure and abutments in IABs, the bridge response to each loading is influenced by the relative stiffness of superstructure to substructure. Under combined loads, the amount of each load effect varied depending on superstructure and substructure stiffness, but the critical load combination for each bridge response was determined in this study. Yielding of piles seems unavoidable for IABs built on sand under combined loads even after the change of pile size or pile orientation, but replacing the soil around top 3m (10ft) of piles with softer material is effective to reduce the significant amount of pile moment for IABs built on sand foundation soil. This thesis includes some design recommendations based on the findings of this study.

This research involves shake table testing of 1g scale models that mimic the coupled seismic response of a structure on a shallow mat foundation and foundation soil (known as soil-foundation-structural-interaction or SFSI). In previous research, SFSI effects have been quantified through analytical models, numerical analyses, and limited field data. This research works towards increasing the amount of empirical data through scale model shake table testing. A suite of earthquake time histories is considered in evaluating a nominal 10th scale soil-structure model using a flexible wall barrel on a 1-D shake table. San Francisco Young Bay Mud (YBM) is used as the prototype soil and long period narrow building as the prototype structure. Foundation embedment depth, fundamental mode of the structure, and seismic loading function are varied to generate a large database of SFSI results under controlled conditions. The foundation level response is compared to free-field responses to determine the magnitude of the SFSI. The results confirm the effects of foundation embedment on the peak ground motion and the spectral acceleration at the predominant period of the structure. The foundation level accelerations are deamplified compared to free-field results. Results also confirm the legitimacy of the testing platform and program by comparing the data to previous experimental study.