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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Integrated modelling of structure-foundation systems

Wotherspoon, Liam M. January 2009 (has links)
A problem endemic in the development of the built environment is poor communication between structural and geotechnical specialists. Through better communication and considering the structure and foundation as an integrated system, new opportunities may arise for achieving superior performance. This thesis investigates the seismic performance of the integrated system through the development of integrated structure-foundation models using the Ruaumoko structural analysis program. A detailed representation of the structural and foundation systems was created using Ruaumoko, providing insight into the response of a range of integrated structure-foundation systems during seismic loading. In developing both shallow and deep foundation models, some modifications were made to Ruaumoko elements in order to improve the foundation model, but generally existing element configurations were used to represent foundations. Multiple structural and foundation designs were developed using a range of approaches. Use of a range of shallow foundation design methods identified the significant impact that moment loading had on foundation performance. Partial uplift of footings was identified as detrimental to footing performance as it shifted the rotational axes, increasing moment loads and reducing effective footing area. Pinned connections between the structure and shallow footings eliminated these effects at the expense of significant redistribution of actions in the structure and increased displacements. Variation of soil conditions showed that softer soil was most likely to reduce demands on the structure at the expense of foundation non-linearity. Reduced stiffness and increased radiation damping characteristics of raft foundations compared to footing foundation systems reduced the demands on three storey structures for all soil conditions. Increased structural demands were identified for the ten storey structure as a result of the reduced impact of foundation characteristics on the response of the integrated system. The level of rotational restraint at the head of pile foundations had a considerable effect on the structure and the foundation, with free-head piles developing the largest pile displacements and actions. Reduced rotational stiffness caused a substantial change in the distribution of structural actions, while increasing rotational restraint moved the characteristics closer to the response of fixed base models. Softer soil conditions greatly increased non-linearity in the foundation soil without any definitive improvement in structural performance.
22

Near fault (near field) ground motion effects on reinforced concrete bridge columns /

Phan, Vu T. January 2005 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2005. / "August, 2005." Includes bibliographical references (leaves 76-78). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
23

Seismic energy dissipation of buildings using engineered cladding systems

Nguyen, Quan Viet, January 2009 (has links)
Thesis (M.S.C.E.)--University of Massachusetts Amherst, 2009. / Open access. Includes bibliographical references (p. 87-89).
24

Seismic behavior of bridge columns subjected to various loading patterns /

Esmaeily-Ghasemabadi, Asadollah. Xiao, Yan. January 1900 (has links)
Based on first author's dissertation. / "December 2002." Includes bibliographical references.
25

Pore pressure generation characteristics of sands and silty sands: a strain approach

Hazirbaba, Kenan 28 August 2008 (has links)
Not available / text
26

Educational shaking table modules for earthquake engineering

Inamdar, Nikhil Jayant 17 February 2011 (has links)
The goal of the project is to develop, build, and test a modular steel structure that can be tested on an educational shaking table to demonstrate structural dynamic and earthquake engineering principles. The advantage of the structure is that it can be tested into its non-linear range and yielded parts can easily be replaced for subsequent tests. The steel modular structure represents a multi-story moment resisting frame and is comprised of sheet metal beams and columns bolted to “rigid” steel angles. This structure is tested on a unidirectional shaking table, viz. “Quanser Shake Table II”. The structure is designed to achieve a specific mode of failure through non-linear analysis. A non-linear pushover analysis is carried out to determine stiffness and strength of the structure as well as potential hinge locations. Eigen-value analysis is undertaken to determine all the natural periods and frequencies that will help in understanding its dynamic response. The structure is analyzed and tested for various ground motions to study the effects of an earthquake on a multi-storied frame. Educational modules provide a set of experiments that can be easily performed on the test structure. / text
27

Performance-based earthquake engineering with the first-order reliability method

Koduru, Smitha Devi 11 1900 (has links)
Performance-based earthquake engineering is an emerging field of study that complements the prescriptive methods that the design codes provide to ensure adequate seismic performance of structures. Accounting for uncertainties in the performance assessments forms an important component in this area. In this context, the present study focuses on two broad themes; first, treatment of uncertainties and the application of the first-order reliability method (FORM) in finite-element reliability analysis, and second, the seismic risk assessment of reinforced concrete structures for performance states such as, collapse and monetary loss. In the first area, the uncertainties arising from inherent randomness (“aleatory uncertainty”) and due to the lack of knowledge (“epistemic uncertainty”) are identified. A framework for the separation of these uncertainties is proposed. Following this, the applicability of FORM to the linear and nonlinear finite-element structural models under static and dynamic loading is investigated. The case studies indicate that FORM is applicable for linear and nonlinear static problems. Strategies are proposed to circumvent and remedy potential challenges to FORM. In the case of dynamic problems, the application of FORM is studied with an emphasis on cumulative response measures. The limit-state surface is shown to have a closed and nonlinear geometric shape. Solution methods are proposed to obtain probability bounds based on the FORM results. In the application-oriented second area of research, at first, the probability of collapse of a reinforced concrete frame is assessed with nonlinear static analysis. By modelling the post-failure behaviour of individual structural members, the global response of the structure is estimated beyond the component failures. The final application is the probabilistic assessment of monetary loss for a high-rise shear wall building due to the seismic hazard in the Cascadia subduction zone. A 3-dimensional finite-element model of the structure with nonlinear material models is subjected to stochastic ground motions in the reliability analysis. The parameters for the stochastic ground motion model are developed for Vancouver, Canada. Monetary losses due to the damage of structural and non-structural components are included.
28

Analysis of prehistoric shoreline structures of Coastal South Carolina and their significance in assessing regional geological stability

Schwartz, Richard Jay 08 1900 (has links)
No description available.
29

The effect of grout and casing on amplitude measurements for borehole seismic testing

Mills, Stephanie Maria 05 1900 (has links)
No description available.
30

Control of seismic response of building structures using passive cladding and active tendon systems

Hsu, Cheng-Chieh 08 1900 (has links)
No description available.

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