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Response of multi-story buildings under earthquake excitationHsu, Tzu-I 05 1900 (has links)
No description available.
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The reponse of multi-story prestressed concrete frames to seismic loadingBannister, David Earl January 1979 (has links)
This thesis is concerned with the response of multi-story prestressed concrete frames to seismic loading, and the ductility demands of the constituent members. In that regard, an idealized model for the end moment-plastic rotation relationship of prestressed concrete members was developed based on a published moment-curvature idealization for prestressed concrete. The idealized moment-rotation model, which included stiffness and strength degradation, was used to introduce all post-elastic action In a beam-column element, which consisted of an elastic beam connecting concentrated hinges modeled as nonlinear rotational springs. The subsequent use of the element in the nonlinear analysis of a typical multi-story prestressed concrete frame indicated that both the lateral displacements, and the girder end rotational and hinge curvature ductilities would be somewhat higher for a prestressed concrete frame than for a reinforced concrete frame with the same initial stiffness and strength. As an effort to limit deflections, and minimize member damage under moderate seismic loading the use of a higher base shear for a prestressed concrete structure than for a comparable reinforced concrete structure appears warranted. / Applied Science, Faculty of / Civil Engineering, Department of / Unknown
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Structural design for earthquake protectionRosebraugh, Warren F January 2010 (has links)
Typescript, etc. / Digitized by Kansas Correctional Industries
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Evaluation, Modeling, and Retrofit of Flat-Slab Buildings subjected to Seismic LoadingJanuary 1995 (has links)
Flat-slab buildings designed and detailed for gravity loads only typically do not have
the ability to resist moderate earthquakes without experiencing severe damage. The
damage potential of such seismically deficient buildings therefore needs to be
assessed and strategies developed to improve their seismic resistance. Punching
failure at slab-column connections in non-ductile flat-slab buildings during
earthquakes can trigger progressive collapse of floor slabs. Based on the test results
of a large number of interior and exterior connections, a methodology is developed
to predict shear and unbalanced moment-transfer capacities of connections under
combined gravity and lateral loads. Furthermore, a frame analysis procedure is
developed based on the equivalent frame concept which targets both the moment-transfer
capacity as well as stiffness of the interior and exterior slab-column
connections. The approach employs a parametric hysteretic model and is based on
the effective slab-width concept. The proposed procedure for evaluating the seismic
capacity of flat-slab connections and frames is verified by comparing the calculated
and measured responses of two-bay flat-slab subassemblies tested under earthquake-type
loading. Seismic reliability against punching failure of slab-column connections
in flat-slab buildings designed for gravity loads was investigated using the proposed
equivalent frame approach. The reliability analysis indicated that the flat-slab
buildings constructed prior to the 1960's could experience significant damage during moderate intensity earthquakes. By limiting the gravity load on floor slabs and by
controlling the lateral drift, the potential for punching failure in flat-slab buildings
can be minimized. The seismic resistance of older flat-slab buildings can be
improved by retrofitting interior connections to protect against progressive collapse
and by utilizing infill walls to control lateral drift. An economical connection retrofit
scheme is proposed and verified experimentally. The equivalent strut concept is used
to model masonry infills whose effectiveness in controlling the lateral drift is
demonstrated through theoretical analysis of typical flat-slab frames.
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Complete design of a three-story reinforced concrete warehouse frame for a seismic locationDotis, John Constantine, 1927- January 1956 (has links)
No description available.
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Subsidence approach to risk of damage in earthquake-induced liquefactionLuettich, Scott M. 05 1900 (has links)
No description available.
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A Methodology for Regional Seismic Damage Assessment and Retrofit Planning for Existing BuildingsMcCormack, Thomas C. 01 January 1996 (has links)
Recent geologic research has shown that earthquakes more destructive than formerly expected are likely to occur in the Pacific Northwest. To mitigate catastrophic loss, planners are gathering information to make decision on implementing regional seismic retrofit programs. This research develops a model to estimate regional earthquake losses for existing buildings, and determine optimal retrofit priorities and budgets. Fragility curves are developed to provide earthquake damage estimates for a range of seismic intensities. The published earthquake damage estimates of a large group of prominent earthquake engineering experts are extended to include the combined effect of structure type, earthquake-sensitive variations in building design, site-specific soil conditions, and local seismic design practice. Building inventory data from a rapid visual screening survey of individual buildings form the basis for modeling structural variations. Earthquake Hazard Maps are the basis of modeling the effect on building damage of ground motion amplification, soil liquefaction, and slope instability. Published retrofit effectiveness estimates and retrofit cost data are used to estimate post-retrofit damage avoided, lives saved, and retrofit cost. A Building Classification System is formulated to aggregate buildings with similar retrofit benefit magnitudes. A cost-benefit analysis is used as the basis for a retrofit prioritization and efficiency analysis, to establish the cut-off point for an optimal retrofit program. Results from an Expected Value and a Scenario Earthquake Event are compared. Regional Earthquake Loss and Retrofit Analysis Program (REAL-RAP) software was developed, and used to make a loss estimate for more than 7,500 buildings inventoried in the 1993 Portland Seismic Hazards Survey. One hundred percent of the loss of life is attributed to only 10-percent of the buildings. A retrofit analysis is made for a Design Basis Earthquake. Twelve-percent of the building inventory was identified for the optimal retrofit program, wherein 98-percent of the loss of life is avoided at less than one-quarter the cost of retrofitting all the buildings. An alternate optimal retrofit program was determined using an Expected Value Analysis. Most of the buildings in the Design Basis Earthquake optimal retrofit program are also contained in the alternate program.
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Seismic considerations in the design of reinforced concrete multi-story structuresMumtaz, Rizwan January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
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Nonlinear seismic response of wall-frame structuresPetalas, Nicholas. January 1979 (has links)
No description available.
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Seismic protection of flexible rotating machines using base isolatorsSu, Wen-Chyi 18 March 1998 (has links)
Base isolation is an alternative seismic design strategy in which the primary structures
and their internal components are uncoupled from the potentially damaging horizontal
components of an earthquake by base isolators which attenuate the transmission of
horizontal acceleration into the system. Rotating machines are among the key internal
components of many modern structures. In this study, flexible rotating machines
protected against seismic excitations by two particular types of base isolation systems,
Resilient-Friction Base Isolation (R-FBI) and Laminated Rubber Bearing (LRB), are
investigated. A comparative study is carried out to compare aseismic responses of base
isolation systems and their corresponding fixed-base ones in protecting a rotating
machine rigidly attached to a floor level or independently isolated.
Finite-element analysis techniques based on energy methods are proposed to
investigate a general complex model of the rotating system which incorporates nonuniform
properties as well as one or more rigid disks along the length of the flexible shaft
and complicated bearing support systems. The equations of motion for the rotating
machines using these methods are developed. An approximate linear analysis to gain
insight into the behavior of a simple linear two-degree-of-freedom isolated structure is
presented. This elementary analysis allows us to develop an analytical expression for the
fundamental frequencies, and their corresponding mode shapes, amplification factors and
design response spectra of base shear. It also demonstrates that the transmission of
ground motion to the systems is effectively controlled through the isolation of the system
at its base. The combined rotating machine-isolator; rotating machine-structure-isolator;
and structure-isolator systems, and their corresponding fixed-base ones are investigated
and compared. The governing equations of motion and the criteria of phase transition (R-FBI only) are presented. Parametric studies to examine the sample response and response
spectra, as well as effects of variations in some system properties including friction
coefficient, damping ratio, mass ratio, ground motion excitation intensity, shaft
flexibility, bearing rigidity and rotating speed, on the response of these systems are
performed. The peak accelerations and relative displacements of the base isolated
systems and corresponding fix-base ones are analyzed and compared. Other response
quantities of special interest such as sliding displacement, residual displacement,
cumulative displacement and relative-to-ground displacement of the structure are also
evaluated. Based on the numerical results, conclusions of the effectiveness of the R-FBI
and LRB systems in protecting the rotating machines and the structures are made. / Graduation date: 1998
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