Yes / In order to improve the efficiency of the structural lateral resistance system, a new type of Grid tubular-Double Steel Plate (GDSP) concrete composite shear walls is proposed and investigated in this paper. Six test specimens, namely one reinforced concrete (RC) shear wall, three GDSP concrete composite shear walls, one concrete-filled steel tube (CFST) frame, one CFST frame and GDSP concrete composite shear wall combined system were physically tested to failure. The seismic performance of the six test specimens, including hysteresis behavior, ductility, energy dissipation, degradation of stiffness and strength, are recorded and compared. The results show that the GDSP concrete composite shear walls exhibited typical bending failure under low reversed cycle loading, achieving good seismic performance with full hysteresis curve, high bearing capacity, excellent ductility, slow degradation of stiffness and bearing capacity. Under the same axial compression ratio, the yield load of GDSP concrete composite shear wall was about 2.73 times, whilst the peak load was 3.23 times, respectively, of those of RC shear wall. On the other hand, the peak displacement of GDSP concrete composite shear wall was 5 times while ultimate displacement was 3.86 times, respectively, of those of RC shear wall. For GDSP concrete composite shear walls, with the increase of axial compression ratio, the peak load of the new types of concrete composite shear wall increases, but the ductility decreases, gradually. The CFST frame and GDSP concrete composite shear wall can work together co-ordinately. The hysteretic curve of the combined system is fuller, the ductility is improved, the degradation of stiffness and strength are slow when compared with GDSP concrete composite shear wall. Under reversed cyclic loading, the GDSP concrete composite shear wall exhibits low stiffness degradation characteristics and excellent fatigue resistance. / The authors would like to acknowledge the financial support to the work by the Natural Science Foundation of Jiangsu Province, China (BK20201436), the Open Foundation of Jiangsu Province Engineering Research Center of Prefabricated Building and Intelligent Construction (2021), the Science and Technology Project of Jiangsu Construction System (2018ZD047, 2021ZD06), the Science and Technology Project of Gansu Construction System (JK2021-19), the Science and Technology Cooperation Fund Project of Yangzhou City and Yangzhou University (YZU212105), the Science and Technology Innovation Fund of Yangzhou University (2020-65) and the Blue Project Youth Academic Leader of Colleges and Universities in Jiangsu Province (2020).

[pt] Os depósitos de solo próximos à superfície podem influenciar significativamente a amplitude, duração e conteúdo de frequências do movimento causado por terremotos. A avaliação de danos causados pelos terremotos indica que os menores níveis de dano se produzem em edificações com fundação em solo rijo, enquanto que os maiores níveis de dano se produzem, em geral, em estruturas fundadas em solo mole. O objetivo desta pesquisa é analisar a resposta sísmica de três sítios conformados por solo mole de alta plasticidade não susceptíveis à liquefação, classificados como sítios tipo E ou F segundo a norma de construção International Building Code, cuja classificação é baseada na velocidade da onda cisalhante nos 30 primeiros metros do perfil de solo. Este estudo focou em realizar simulações numéricas, chamadas análises de resposta de sítio com terremotos de projeto em rocha determinados em função do estudo de ameaça sísmica local. Foram usados os programas de análise de propagação de ondas 1D SHAKE2000 e D-MOD2000. O primeiro incorpora o modelo de análise linear equivalente. O segundo é um programa de análise não linear baseado no modelo constitutivo hiperbólico MKZ, com capacidade de realizar análises em termos de tensões totais e em termos de tensões efetivas mediante modelos de degradação cíclica e geração e redistribuição de poropressão. Este estudo verificou que movimentos de alta intensidade propagados verticalmente através de um perfil de solo mole induz altos níveis de deformação cisalhante resultando em um maior amortecimento do solo o que produz a atenuação das acelerações. Na análise das histórias de deslocamento relativo, observou-se vários ciclos com deslocamentos máximos entre 12 e 24 cm, o que sugere que o deslocamento poderia ser um parâmetro mais representativo do potencial de dano do movimento, observando-se que o deslocamento, em oposição à aceleração, é amplificado à medida que a intensidade do movimento aumenta. / [en] Near surface soils can greatly influence the amplitude, duration, and frequency content of ground motions. The survey of damage caused by earthquakes indicates that the lowest levels of damage occur in structures founded on rock or hard soil, while most of the damage occurs usually in structures founded in soft soil sites. The scope of this research is to analyze the seismic response of three sites with high plasticity soft soil deposits not susceptible to liquefaction, classified as sites E or F according to the building code International Building Code, whose classification is defined by the time averaged shear wave velocity over the top 30 meters of the soil deposit. This study focused on generating data from numerical simulations, called site response analyses. To this end, design earthquakes on rock are determined considering the local seismic hazard. For this study the programs of one-dimensional wave propagation analysis SHAKE2000 and D-MOD2000 were used. The first one is a well known code for the equivalent linear method. The second, is a nonlinear analysis code based on the hyperbolic constitutive model MKZ, capable of performing analyses in terms of total stresses and in terms of effective stresses incorporating models of cyclic degradation and, generation and redistribution of pore pressure for sands and clays. This study verified that high intensity motions vertically propagated through a soft soil profile induce high levels of shear strain resulting in greater soil damping which produces the attenuation of the acceleration. From the analysis of the relative displacement histories of the ground, which shown many cycles with a maximum displacement between 12 and 24 cm, it is suggested that the displacement could be a more representative parameter of the potential of damage of strong motions, showing that the displacement, as opposed to the acceleration, is amplified as the intensity of the motion increases.

Steel plate shear walls (SPSWs) are popular lateral force resisting systems whose practical applications range from high seismic regions to medium and low seismic areas and wind load applications. The factors which make SPSW attractive include its energy dissipation capacity, excellent ductility, constructability, speed of construction compared to concrete shear walls, reduced architectural footprint compared to concrete shear walls, and increased inelastic deformation capacity as compared to braced frames. The principle behind current SPSW design is that the post-buckling tension field capacity of the thin web plate is proportioned to resist the full lateral load. The resulting web plate is typically quite thin, buckles at low loads, possesses low stiffness, and does not provide resistance when the lateral loads are reversed until the tension field engages in the opposite direction. To compensate for these shortcomings, moment connections are required at the beam to column connections to improve energy dissipation, increase stiffness, and provide lateral resistance during load reversal. The resulting SPSW designs with very thin web plates, moment connections, and beams and columns significantly larger than comparable braced frames, can result in inefficient structural systems. The objective of this work is to develop steel plate shear wall systems that are more economic and efficient. In order to achieve this, approaches like shear connections between beams and columns, allowing some yielding in columns and increasing plate thicknesses were attempted. But these approaches were not effective in that there was no reduction in the amount of steel required since stiffness controlled the designs. This necessitated the creation of tunable steel plate shear wall systems in which strength and stiffness could be decoupled. Preliminary analyses of seven steel plate shear wall systems which allow tunability were conducted and two configurations namely circular holes and butterfly shaped links around the perimeter, that showed promising results were chosen. The solid plate in the middle of the panel contributes significant pre-yield stiffness to the system while the geometry of the perimeter perforations controls strength and ductility. An example panel was designed using the two approaches and compared to panels designed using current SPSW design methods. The proposed configurations resulted in improved overall performance of the system in terms of energy dissipation, stable hysteresis, required less steel and no moment connections between beams and columns. This was also observed from the parametric study that was performed by varying the thickness of the web plate and the geometry of the configurations. Thus it was concluded that the two proposed configurations of cutouts were promising concepts that allow separate tuning of the system strength, stiffness and ductility and could be adopted in any seismic zone for improved seismic resistance. / Master of Science

Steel plate shear walls (SPSWs) are an attractive option for lateral load resisting systems for both new and retrofit construction. They, however, present various challenges that can result in very thin web plates and excessively large boundary elements with moment connections, neither of which is economically desirable. Moreover, SPSW also suffers from buckling at small loads which results in highly pinched hysteretic behavior, low stiffness, and limited energy dissipation. To mitigate these shortcomings, a new type of SPSW has been developed and investigated. The buckling resistant steel plate shear wall (BR-SPSW) utilizes a unique pattern of cut-outs to reduce buckling. Also, it allows the use of simple shear beam-column connections and lends tunability to the shear wall system. A brief discussion of the concept behind the BR-SPSW is presented. A detailed parametric study is presented that investigates the sensitivity of the local and global system behavior to the geometric design variables using finite element models as the main tool. The key output parameters which define the system response are discussed in detail. Analytical solutions for some output parameters like strength and stiffness have been derived and resulting equations are proposed. Finally, preliminary suggestions have been made about how this system can be implemented in practice to improve the seismic resistance of the buildings. The proposed BR-SPSW system was found to exhibit relatively fuller hysteretic behavior with high resistance during the load reversals, without the use of moment connections. / Master of Science

Traditionally, earthquake engineering has focused on protecting the lives of building occupants by utilizing inelasticity in structural members and connections to dissipate seismic energy and provide protection against collapse. This design concept is partially based on the equal displacement concept, which states that peak drifts for an inelastic system will be approximately equal to the peak drifts of an elastic system with the same initial stiffness for a given dynamic loading. This is a concept that has been shown to work for structures with natural period greater than about 1.0 seconds, but does not hold true for shorter period structures. An additional consequence of this design methodology is that conventional seismic systems do not explicitly limit the amount of structural damage, or offer a repair method that allows continued use of a structure after an earthquake. In fact, the structural damage distributed throughout a building and permanent residual drifts can make a conventional structure difficult if not financially unreasonable to repair after a large earthquake. These are both concerns facing the seismic design community that are investigated as a part of this thesis. First, a computational study was conducted on short period structural systems to investigate the relationship between initial structural period and collapse potential. The investigation utilizes a statistically based analysis methodology to investigate a study of single degree of freedom (SDOF) systems with periods between 0.1 seconds and 1.0 seconds. The SDOF models were developed using an elastic-linear hardening model with post-yield stiffness ranging between -10% and +10% of the initial stiffness. This part of the study was done to gain a general understanding of the influence of natural period and post-yield behavior on the collapse performance of structural systems and appropriate response modification factors. Next, a study of multi-degree of freedom (MDOF) masonry structures with short periods was conducted to examine how the SDOF trends translated to realistic MDOF structures. Based on these two studies, recommendations were made for how current U.S. building codes could be modified to account for the behavior of short period structures. Next, a new self-centering system that builds on the concepts of previous self-centering systems is developed. The self-centering truss moment frame (SC-TMF) was developed with the goal of providing self-centering capability while concentrating inelastic deformation in replaceable structural fuses. These goals are accomplished while mitigating a number of issues seen in other self-centering systems, such as deformation incompatibility with gravity framing, limited deformation capacity, and unusual field construction techniques. The development of the SC-TMF includes a set of preliminary monotonic pushover analyses and nonlinear time history analyses to confirm the expected behavior of the system. Next, a mechanics investigation was undertaken where static pushover analyses (monotonic and cyclic) were used to help derive equations to predict system behavior, such as strength and stiffness. Finally, a parametric study was conducted to gain a better understanding of how various design decisions influence structural behavior. It was shown that the SC-TMF was a viable seismic system for controlling residual drifts and concentrating inelasticity in replaceable fuse elements while mitigating the issues seen in other conventional self-centering systems. / Master of Science

Post-tensioning (PT) strands have been employed in a number of self-centering seismic force resisting systems as part of the restoring force mechanism which virtually eliminates residual building drifts following seismic loading. As a result of the PT strands large elastic deformation capability, they have been proven to work efficiently in these types of systems. Although typically designed to stay elastic during design basis earthquake events, strands may experience inelastic cyclic loading during extreme earthquakes. Furthermore, the yielding and fracture behavior of PT strand systems is central to the collapse behavior of self-centering systems. The loading conditions to which PT strands are typically subjected in prestressed/post-tensioned concrete applications are vastly dissimilar, and only limited research has explored the behavior of PT strands as subjected to inelastic cyclic loading. The testing program conducted to characterize the behavior of PT strand systems as they might be applied in self-centering applications incorporated more than fifty tests, including monotonic and cyclic tests to failure. Variations in the test configuration included strand obtained from two manufacturers, single-use and multiple-use anchorage systems, and variations in initial post-tensioning strand stress. Characteristics of the response that were investigated included seating losses, deformation capacity prior to initial fracture, additional deformation capacity after initial fracture, and the overall load-deformation behavior. Data was analyzed to provide recommendations for PT strand system usage in self-centering seismic force resisting systems. It was concluded that significant strength and ductility allow PT strand systems to consistently provide self-centering systems with reliable restoring force capability. / Master of Science

In this dissertation, the seismic behavior and design of AAC-infilled steel moment frames are investigated systematically. The fundamental vehicle for this investigation is the ATC-63 methodology, which is intended for the establishment of seismic design factors for structural systems. The ATC-63 methodology is briefly reviewed, including the concepts of archetypical structures, design rules and mathematical models simulating the behavior of those archetypes. A limited experimental investigation on the hysteretic behavior of an AAC-infilled steel moment frame is developed, conducted, and discussed. Using the experimental results of that investigation, the draft infill design provisions of the Masonry Standards Joint Committee (MSJC) are extended to AAC infills, and a mathematical model is developed and calibrated to simulate the behavior of AAC infills under reversed cyclic loads. Prior to application of ATC-63 methodology to AAC-infilled steel moment frames, the methodology is applied to an example steel moment frame to demonstrate the methodology and verify understanding of it. Then, archetypical infilled frames to be evaluated by the ATC-63 methodology are developed using a series of pushover analyses. Infill configurations whose total lateral strength in a particular story exceeds about 35% of the lateral strength of the bare frame in that story are observed to provoke story mechanisms in the frame. Based on this observation, archetypical infilled frames are selected conforming to two infill configurations: uniformly infilled frames, and open ground story frames. Each infill configuration includes archetypes whose ratio of infill strength to bare-frame strength at each story is less than 35%, and archetypes whose ratio is greater than 35%. The former archetype is typical of steel moment frames infilled with AAC; the latter archetype is typical of steel moment frames infilled with conventional (clay or concrete) masonry. The ATC-63 methodology, specialized for application to infilled frames, is applied to the archetypical infilled frames developed above. The performance of those archetypical infilled frames is evaluated, and seismic design factors are proposed for AAC-infilled steel moment frames. The extension of this work to other types of infilled frames is discussed. / text

Container cranes represent one of the most critical components of ports worldwide. Despite their importance to port operations, the seismic behavior of cranes has been largely ignored. Since the 1960s, industry experts have recommended allowing cranes to uplift, believing that it would limit the amount of seismic loading. However, modern cranes have become larger and more stable, and the industry experts are now questioning the seismic performance of modern jumbo cranes. The main goal of this research was to experimentally investigate the seismic behavior of container cranes from the general elastic behavior through collapse, including non-linear behavior such as buckling and cross section yielding, utilizing the 6 degree-of-freedom shake tables at the University at Buffalo. The testing was divided into two phases. The first phase of testing was conducted on a 1/20th scale model. The second phase of testing was conducted on a 1/10th scale model, which was designed such that no inelastic action would develop prior to uplift (as is the common design practice). In support of the experiments, finite element models were created to determine what simplifications could be made to the structure to aid in testing. The data collected from the testing has been used to validate finite element models, to give a better understanding of the behavior of container cranes under seismic excitations, validate fragility models, and to develop recommendations and guidelines for the design and testing of container cranes.

No description available.

[pt] O Peru está localizado em uma área de alta atividade sísmica conhecida como cinturão de fogo. Os terremotos registrados com diferentes mecanismos de falha resultam da interação entre as placas tectônicas de Nazca e Sul-americana. É nesta região onde acontecem atividades de mineração no país, juntamente com a construção de grandes estruturas civis, como barragens de rejeitos, projetadas para armazenar grande quantidade de material na menor área possível. Neste trabalho, foi avaliado o comportamento sísmico de uma barragem de rejeitos localizada em Arequipa, Peru, construída com o método a montante. Em evento sísmico ocorrido em 2013, a barragem sofreu trincas no seu corpo, recalques na crista e pequenos vulcões de areia, indicando a redução dos parâmetros de resistência no rejeito devido a possível fenômeno de liquefação. Nesta pesquisa, a estimativa da ameaça sísmica foi feita por métodos probabilísticos, com o terremoto artificial de projeto obtido por método de ajuste espectral. Foram feitas análises pseudo-estáticas de estabilidade dos taludes, bem como estimados deslocamentos permanentes e o potencial de liquefação dinâmica por métodos simplificados. A análise global da barragem de rejeitos foi executada pelo método dos elementos finitos, considerando o modelo constituivo UBC3D-PLM para simular o comportamento mecânico dos rejeitos sob carregamento cíclico. / [en] Peru is located in an area of high seismic activity known as the fire belt. Earthquakes recorded with different failure mechanisms result from the interaction between the Nazca and South-American tectonic plates. It is in this region where mining activities take place in the country, along with the construction of large civil structures, such as tailings dams, designed to store large amounts of material in the smallest possible area. In this work, the seismic behavior of a tailings dam located in Arequipa, Peru, built with the upstream method, was evaluated. In a seismic event that occurred in 2013, the dam suffered cracks in its body, settlement in the crest and small sand boils, indicating the reduction of the tailings resistance parameters due to possible dynamic liquefaction. In this research, the seismic hazard assessment was made by probabilistic methods, with the artificial design earthquake obtained by the spectral adjustment method. Pseudo-static analyzes of slope stability were performed, as well as the estimated permanent displacements and the potential of dynamic liquefaction were obtainded by simplified methods. The global seismic analysis of the tailings dam was carried out through the finite element method, considering the UBC3D-PLM constitutive model to simulate the mechanical behavior of tailings under cyclic loading.