Spelling suggestions: "subject:"buildings -- earthquake effects"" "subject:"buildings -- arthquake effects""
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Determination of earthquake intensities from chimney damage reportsHo, Alan Darrell January 1979 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Alan Darrell Ho. / M.S.
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Development of HAZUS relative loss methodology for multi-hazard mitigation programsLessard, Katie 01 October 2002 (has links)
No description available.
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Seismic response of structures with Coulomb dampingMalushte, Sanjeev R. January 1989 (has links)
The usefulness of Coulomb (friction) damping in earthquake-resistant design of structures is examined by studying the seismic response characteristics of structures with various arrangements of sliding interfaces. First, three basic arrangements are studied for their effectiveness in reducing lateral displacements of the supporting frame, accelerations of the floor slab and the resulting secondary floor spectra. These are: (1) slab sliding system which has the sliding interface between the floor slab and the supporting frame, (2) double sliding system which consists of sliding interfaces at both top and bottom interfaces (a combination of slab sliding and base sliding), and (3) spring-assisted slab sliding system which is a slab sliding system aided by lateral springs attached to the columns to resist excessive sliding displacement of the slab. The responses are obtained for structures with different frequencies and are presented in response spectrum form. The isolation characteristics of one slab sliding system are compared with those of the base sliding and hysteretic systems. Non-dimensional design parameters defined in terms of the corresponding elastic design spectra are introduced for design purposes and for a consistent presentation of the results. Methods for predicting the important response quantities using the non-dimensional parameters are discussed and their applicability is evaluated.
Next, the response of a simple slab sliding arrangement to simultaneous horizontal and vertical ground motion input is studied to see the effects of the vertical excitation on the isolation efficiency of that arrangement. Finally the suitability of adopting such sliding arrangements in multi-story structures is also examined. The seismic responses of multi-story structures with floor slabs sliding at different story levels are obtained and compared with the response of non-sliding structure and base sliding to examine the effectiveness of such sliding arrangement. / Ph. D.
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Effect of seismic loads on water-retaining structures in areas of moderate seismicityFourie, Johanna Aletta 03 1900 (has links)
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Water-retaining structures are commonly used in South Africa for the storage of potable water and
waste water. However, a South African code pertaining to the design of concrete water-retaining
structures do not currently exist and therefore use is made of the British Standard BS 8007 (1987).
For the design of concrete water-retaining structures in South Africa, only the hydrostatic loads are
considered while forces due to seismic activity are often neglected even though seismic excitations
of moderate magnitude occur within some regions of the country. Hence, the primary aim of this
study was to determine whether seismic activity, as it occurs in South Africa, has a significant
influence on water-retaining structures and whether it should be considered as a critical load case.
In order to assess the influence of seismic activity on the design of water-retaining structures the
internal forces in the wall and the required area of reinforcement were compared. Comparisons
were made between the seismic analyses and static analyses for both the ultimate and serviceability
limit states. In order to obtain the internal forces in the wall use was made of an appropriate Finite
element model. Three Finite element models were investigated in this study and the accuracy of
each model was assessed based on the fundamental frequency, base shear force and overturning
moment. These values were compared to the values obtained with the numerical method presented
by Veletsos (1997) which was verified with Eurocode 8: Part 4 (2006).
The results obtained indicated that seismic excitations of moderate magnitude do have a significant
influence on the reinforcement required in concrete water-retaining structures. For both the
ultimate limit state and serviceability limit state the required reinforcement increased significantly
when seismic loads were considered in the design. As in the case for static design of water-retaining
structures, the serviceability limit state also dominated the design of these structures under seismic
loading. / AFRIKAANSE OPSOMMING: Beton waterhoudende strukture in Suid-Afrika word op ‘n gereelde basis gebruik vir die stoor van
drink- sowel as afvalwater. ‘n Suid-Afrikaanse kode vir die ontwerp van hierdie strukture bestaan
egter nie en dus word die Britse kode BS 8007 (1987) hiervoor gebruik. Vir ontwerp doeleindes word
soms slegs die hidrostatiese kragte beskou terwyl kragte as gevolg van seismiese aktiwiteite nie
noodwendig in berekening gebring word nie. Seismiese aktiwiteite van gematigde grootte kom egter
wel voor in sekere dele van Suid-Afrika. Die hoofdoel van hierdie studie was dus om die invloed van
seismiese aktiwiteite, soos voorgeskryf vir Suid-Afrikaanse toestande, op beton waterhoudende
strukture te evalueer asook om te bepaal of dit ‘n kritiese lasgevalle sal wees.
Vir hierdie doel is die interne kragte asook die area staal bewapening vir elk van die statiese en
dinamiese lasgevalle vergelyk. Vergelykings is getref tussen die dinamiese en statiese resultate vir
beide die swigtoestand en die diensbaarheidstoestand. Vir die bepaling van die interne kragte is
gebruik gemaak van eindige element modelle. Tydens hierdie studie was drie eindige element
modelle ondersoek en die akkuraatheid van elk geëvalueer op grond van die fundamentele
frekwensie, die fondasie skuifkrag en die omkeermoment. Hierdie waardes was ondermeer bereken
met twee numeriese metodes soos uiteengesit in Veletsos (1997) en Eurocode 8: Part 4 (2006).
Die resultate dui daarop dat die invloed van seismiese aktiwiteite op beton waterhoudende
strukture in Suid-Afrika nie weglaatbaar klein is nie en wel in berekening gebring behoort te word
tydens die ontwerp. Die interne kragte vir beide die swigtoestand en diensbaarheidstoestand is
aansienlik hoër vir die seismiese lasgeval as vir die statiese geval. Die diensbaarheidstoestand het
deurentyd die ontwerp van beton waterhoudende strukture vir seismiese toestande oorheers.
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The effect of seismic activity on reinforced concrete frame structures with infill masonry panelsJarvis, Wesley James 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Certain regions within the Western Cape Province are at risk of a moderate intensity
earthquake. It is therefore crucial that infrastructure in these areas be
designed to resist its devastating effect. Numerous types of structural buildings
exist in these seismic prone areas. The most common types are either reinforced
concrete framed buildings with masonry infill or unreinforced masonry
buildings. Many of these buildings predate the existence of the first loading
code of 1989 which provided regulations for seismic design. The previous code
was superseded in 2010 with a code dedicated to providing guidelines for seismic
design of infrastructure. A concern was raised whether these buildings
meet the requirements of the new code. A numerical investigation was performed
on a representative reinforced concrete framed building with masonry
infill to determine whether the building meets the new code’s requirements.
The results from the investigation show that the stresses at critical points in
the columns exceed the codified requirements, thus leading to local failure.
After careful review it was discovered that these local failures in the columns
will most likely lead to global failure of the building. / AFRIKAANSE OPSOMMING: In sekere streke in die Wes-Kaap bestaan daar risiko van matige intensiteit
aardbewings. Dit is dus noodsaaklik dat die infrastruktuur in hierdie gebiede
ontwerp word om die vernietigende uitwerking te weerstaan. Gebous
met verskillende tipes strukturele uitlegte kom in hierdie gebied voor. Die
mees algemene struktuur tipe is gewapende beton-raam geboue met baksteen
invol panele sowel as ongewapende baksteen geboue. Baie van hierdie geboue
is gebou voor die eerste las-kode van 1989 wat regulasies vir seismiese ontwerp
voorsien in gebruik geneem is. Die vorige kode is vervang in 2010 met ’n
kode toegewy tot die verskaffing van riglyne vir seismiese ontwerp van infrastruktuur.
Kommer het ontstaan of hierdie geboue voldoen aan die vereistes
van die nuwe kode. ’n Numeriese ondersoek is uitgevoer op ’n verteenwoordigende
gewapende beton geraamde gebou met baksteen panele om te bepaal
of die gebou voldoen aan die nuwe kode vereistes rakende sismiese ontwerp.
Die resultate van die ondersoek toon dat die spanning op kritieke punte in
die kolomme die gekodifiseerde vereistes oorskry, wat tot plaaslike faling lei.
Na verdere onderssoek is dit bepaal dat die plaaslike faling in die kolomme
waarskynlik tot globale faling van die gebou sal lei.
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Earthquake resistant design of precast panel buildings : a case studyBurns, Joseph Gilmary January 1981 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering; and, (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: p. 175-178. / by Joseph Gilmary Burns. / M.S.
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The effects of earthquake excitations on reticulated domesUliana, David A. 14 November 2012 (has links)
Comparisons were made on the behavior of two full-sized reticulated domes subjected to uniform static loads only and uniform static loads with earthquake excitations. Space truss elements were used in the dome models. The stiffness matrix of the space truss element allows for the nonlinear strain-displacement behavior and the stress-strain behavior of the material is modeled with a bilinear approximation. The nonlinear solution technique is the Newton-Raphson method while the direct integration technique is the Newmark- Beta method.
The joint displacements for the static and the dynamic analyses were compared for both domes along with the axial stresses in all members. The percentage increases in the axial stresses of the dynamic analyses as compared to those of the static analyses were determined.
The reticulated domes used in the study were found to bet capable of withstanding the earthquake excitations when subjected to various uniform loads without failure. / Master of Science
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Seismic behavior and rehabilitation of a four-storey steel buildingVazquez, Gerardino Aixa 01 July 2000 (has links)
No description available.
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The seismic analysis of a typical South African unreinforced masonry structureVan Der Kolf, Thomas 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: South Africa has some regions which are susceptible to moderate seismic activity. A peak ground
acceleration of between 0.1g and 0.15g can be expected in the southern parts of the Western
Cape. Unreinforced Masonry (URM) is commonly used as a construction material for 2 to 4
storey buildings in underprivileged areas in and around Cape Town. URM is typically regarded
as the material most vulnerable to damage when subjected to earthquake excitation. In this
study, a three-storey URM building was analysed by applying seven earthquake time-histories,
that can be expected to occur in South Africa, to a finite element model. Experimental data was
used to calibrate the in- and out-of-plane stiffness of the URM. A linear modal dynamic analysis
and non-linear implicit dynamic analysis were performed. The results indicated that tensile
cracking of the in-plane piers was the dominant failure mode. The building relied on the postcracking
capacity to resist the 0.15g magnitude earthquake. It is concluded that URM buildings
of this type are at risk of failure especially if sufficient ductility is not provided. The results
also showed that connection failure must be investigated further. Construction and material
quality will have a large effect on the ability of typical URM buildings to withstand moderate
magnitude earthquakes in South Africa. / AFRIKAANSE OPSOMMING: Sekere gebiede in Suid-Afrika het ’n risiko van matige seismiese aktiwiteit. Aardbewings met
maksimum grondversnellings van tussen 0.1g en 0.15g kan in die suidelike gedeeltes van die Wes-
Kaap voorkom. Twee- tot vier-verdieping onbewapende messelwerkgeboue kom algemeen voor
in die lae sosio-ekonomiese gebiede van Kaapstad. Oor die algemeen word onbewapende messelwerkgeboue
as die gebou-tipe beskou wat die maklikste skade opdoen tydens aardbewings. In
hierdie studie is sewe aardbewings, wat tipies in Kaapstad verwag kan word, identifiseer en gebruik
om ’n tipiese drie-verdieping onbewapende messelwerkgebou te analiseer. Eksperimentele
data is gebruik om die materiaaleienskappe in die in-vlak asook uit-vlak rigtings te kalibreer.
Beide ’n liniêre modale en nie-liniˆere implisiete dinamiese analises is uitgevoer. Die resultate dui
daarop dat die dominante falingsmode die kraak van in-vlak messelwerk-tussenkolomme is. Die
gebou moes sy plastiese kapasiteit benut om die 0.15g aardbewing te kan weerstaan. Die gevolgtrekking
is dat dié tipe onbewapende messelwerkgeboue ’n risiko inhou om mee te gee, veral as
genoegsame vervormbaarheid nie verskaf word nie. Die resultate toon ook dat konneksie-faling
verder ondersoek moet word. Kwaliteit van vakmanskap en van materiaal het ’n groot invoed
op die vermoë van onbewapende messelwerkgeboue om aardbewings van matige intensiteit in
Suid-Afrika te weerstaan.
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Probabilistic Seismic Demand Assessment of Steel Frames with Shape Memory Alloy ConnectionsTaftali, Berk 09 July 2007 (has links)
Shape Memory Alloys (SMAs) exhibit the ability to undergo large deformations but can recover permanent strains via heating (shape memory effect) or when stress is removed (superelastic effect). This study evaluates the comparative seismic performance of steel moment resisting frames (SMRFs) with innovative beam-to-column connections that use SMA bars as connecting elements. The performance evaluation studies are based on two types of SMA beam-to-column connections: (1) superelastic SMA connections with recentering capability; (2) martensitic SMA connections with high energy dissipation capacity. Fiber models for these SMA connections are implemented in the OpenSees finite element framework, and are verified against data from full-scale experimental tests that were performed on a prototype SMA connection in previous research at Georgia Tech. Three- and a nine-story model buildings with partially-restrained (PR) moment frames are selected from the SAC Phase II Project as case studies. Non-linear time history analyses on these model buildings, with and without SMA connections, are conducted using suites of ground acceleration records from the SAC Phase II project that represent different seismic hazard levels. Several SMA connections are designed for each structure, and their effect on peak and residual inter-story drift angles, connection rotations, and normalized dissipated hysteretic energy demands are investigated to determine the most suitable design. Finally, the seismic demands on the model buildings with conventional PR and selected SMA connections are evaluated in a probabilistic framework. The resulting seismic demand relationships are used to assess the effectiveness of the SMA connections in enhancing the building performance over a range of demand levels.
The results of this performance evaluation show that the SMA connections are most effective in controlling structural response under high levels of seismic intensity leading to large deformation demands. In particular, the energy dissipating SMA connections are found to be effective in reducing maximum deformation demands, while the recentering SMA connections are more suitable for controlling residual deformations in the structure.
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