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Developments of Advanced Solutions for Seismic Resisting Precast Concrete FramesAmaris Mesa, Alejandro Dario January 2010 (has links)
Major advances have been observed during the last two decades in the field of seismic engineering with further refinements of performance-based seismic design philosophies and the subsequent definition of corresponding compliance criteria. Following the globally recognized expectation and ideal aim to provide a modern society with high (seismic) performance structures able to sustain a design level earthquake with limited or negligible damage, alternative solutions have been developed for high-performance, seismic resisting systems.
In the last two decades, an alternative approach in seismic design has been introduced for precast concrete buildings in seismic regions with the introduction of “dry” jointed ductile systems also called “hybrid” systems based on unbonded post-tensioned rocking connections. As a result structural systems with high seismic performance capabilities can be implemented, with the unique capability to undergo inelastic displacement similar to their traditional monolithic counterparts, while limiting the damage to the structural system and assuring full re-centring capabilities (negligible residual or permanent deformations).
The continuous and rapid development of jointed ductile connections for seismic resisting systems has resulted in the validation of a wide range of alternative arrangements, encompassed under the general umbrella of “hybrid” systems.
This research provides a comprehensive experimental and analytical investigations of 2- and 3-Dimensional, 2/3 scaled, exterior beam-column joints subjected both uni and bi-directional (four clove) quasic-static loading protocols into the behaviour, modelling, design and feasibility of new arrangements for “dry” jointed ductile systems for use in regions of high seismicity. In order to further emphasize the enhanced performance of these systems, a comparison with the experimental response and observed damage of 2-D and 3-D monolithic beam-column benchmark specimens is presented.
However, after a lot of attention given to the behaviour of the skeleton structure, more recently the focus of research in Earthquake Engineering has concentrated on the behaviour of the floor system within the overall 3D behaviour of the building and the effects of beam elongation. The effects of beam elongation in precast frame systems have been demonstrated to be a potential source of un-expected damage, unless adequate detailing is provided in order to account for displacement incompatibilities between the lateral resisting systems and the floor. Two contributions to beam elongation are typically recognized: a) the material contribution due to the cumulative residual strain within the steel, and b) the geometrical contribution due to the presence of a neutral axis and actual depth of the beam.
Regarding jointed ductile connections with re-centering characteristics, the extent of beam elongation is significantly reduced, being limited to solely the geometrical contribution. Furthermore, such effects could be minimized when a reduced depth of the beam is adopted due to the use of internal prestressing or external post-tensioning. However, damage to precast floor systems, resulting from a geometric elongation of the beam, has yet to be addressed in detail.
In order to emphasize the enhanced performance in controlling and minimizing the damage of the structural elements via the use of the proposed advanced hybrid solutions, this research presents via experimental and analytical validation of two alternative and innovative solutions to reduce the damage to the floor using 2 and 3-Dimensional, 2/3 scaled, exterior beam-column joints.
The first approach consists of using standard precast rocking/dissipative frame connections (herein referred to as “gapping”) in combination with an articulated or “jointed” floor. This system uses mechanical devices to connect the floor and the lateral beams which can accommodate the displacement incompatibilities in the connection. The second approach to reduce the floor damage investigates the implementation of a “non-gapping” connection, also called non-tearing-floor connection, using a top hinge at the beam-column interface, while still relying on more traditional floor-to-frame connections (i.e. topping and continuous starter bars). Additionally, further refinements and constructability issues for the non gapping connection are investigated under the experimental and analytical validation of a major 2-Dimensional, 2/3 scaled, two-story one-bay frame using non-tearing floor connections.
Based on the non-tearing floor connections, a series of parametric analysis for beam-column joints and frames are carried out. Furthermore, the analysis and design of two prototype frames using different solutions is presented. The frames are subjected to cyclic adaptive pushover and inelastic time history analysis in order to investigate analytically the response characteristics of hybrid frames using non-tearing connections, as well as how the beam growth affects the frame response under earthquake loading. Computational models for hybrid PRESSS frames and a conventional reinforced concrete frames are developed and compared with the ones using non-tearing connections.
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A study of precast reinforced concrete skeleton for low-cost housing /Sun, Minhui January 1991 (has links)
This thesis is a survey of the precast reinforced concrete skeleton system used in low-cost housing (SPCSS), which has widely spread to different areas of the world, but less studied. The thesis includes three major parts: (1) the development of SPCSS; (2) the design, performance feature of SPCSS; and (3) cases studies. / The development of SPCSS traces its origin as the structure of prefabricated houses for the housing shortage after the world war in Europe to its spread to developing countries for low-cost housing. / Design and performance study focuses on its features related to low-cost housing its special considerations and key points in design as a small component system, its acclaimed system performance features. / Case studies surveys 15 typical cases. Each case includes general background of the system, system design, comments following the design consideration and example of its application.
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Designing flexible mould for prefabs by using commonality analysis /Yip, Chong Kei. January 2008 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 104-106). Also available in electronic version.
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Seismic analysis, behavior, and design of unbonded post-tensioned precast concrete frames /El-Sheikh, Magdy Thabet Mahmound, January 1997 (has links)
Thesis (Ph. D.)--Lehigh University, 1997. / Includes vita. Includes bibliographical references (leaves 450-455).
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Experimental and analytical lateral load response of unbonded post-tensioned precast concrete walls /Perez, Felipe de Jesus, January 2004 (has links)
Thesis (Ph. D.)--Lehigh University, 2004. / Includes vita. Includes bibliographical references (leaves R1-R7).
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Development of a precast bent cap system /Matsumoto, Eric Eiji, January 2000 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 556-561). Available also in a digital version from Dissertation Abstracts.
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An investigation into the feasibility of hybrid concrete construction in South Africa /Jurgens, Christiaan Johannes. January 2008 (has links)
Thesis (MScEng)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.
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Precast concrete load bearing wall panelsChandwani, Ramesh Hassanand January 1970 (has links)
The object of this thesis is twinfold. Firstly, to study and check the effective width requirements recommended by different committees¹ for the design of ribbed precast concrete load bearing walls. Secondly, to rationalize the practice of the designing of the precast prefabricated components of any general polygonal shape.
The recommendations regarding the minimum thickness of a thin wall, the effective width, etc., have been specified for some cases in code books and other tentative specification books², in the form of rules of thumb.
In these rules of thumb, several parameters which may be of significance, such as dimensions of the rib itself, are not taken into account. A finite element approach has been adopted to investigate various combinations of these parameters, as well as the effects of different boundary conditions.
Similar problems arise also in the cases of T-beams, L-beams and design of aircraft structures, in which a stressed skin is mounted on ribs, which are assembled in the form of a space frame.
So far interaction curves have been made available in some design books only for the prestressed concrete member having rectangular cross-sections and for any other shape, approximations are made, such as making a rectangular section having an equivalent area or having the same moment of inertia or section modulii, etc. But this practice seems very irrational especially in the case of precast components which are always produced in a factory on a mass scale. A computer program has been written which can give the interaction curve for the member of any polygonal shape.
1. DRAFT 3: Of PCI Committee, 'Recommendations for Prestressed Bearing Wall Design.'
2. 'Symposium on Precast Concrete Wall Panels.' Publications ACI, SP-11, Second Printing 1966, pp. 39-44. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
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Some experiments on headed stud connections for precast concrete panels under monotonic and cyclic shear loadingBischof, Max January 1978 (has links)
The research on headed stud connections described in this thesis forms a part of a larger program with the objective of predicting the behaviour of precast concrete panel buildings under earthquake loads.
The first objective of this research is to produce experimentally a concrete failure of the connection and to compare the actual failure load to the one predicted by the PCI design handbook. The tests show that the PCI shear-tension interaction equation for single headed studs can be used for the prediction of a concrete failure for a connection of the type tested. This method yields conservative results if a special equilibrium model for the determination of the stud tension force is used, and the bearing capacity of the structural steel angle on the concrete is neglected.
The second objective of this research is to determine the bearing capacity of a reversed angle connection. Experiments show that this bearing capacity is equivalent to a force resulting from a stress equal to the concrete strength uniformly distributed over the concrete area enclosed by the structural steel angle 2" x2". Furthermore, the location of this force can be assumed in the center of gravity of the structural steel angle shape, regardless of whether or not there is an endplate present. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
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A study of precast reinforced concrete skeleton for low-cost housing /Sun, Minhui January 1991 (has links)
No description available.
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