EARTHQUAKE-RESISTANT CONFINED MASONRY CONSTRUCTION
Author: Svetlana Brzev Department of Civil Engineering British Columbia Institute of Technology Burnaby, BC, Canada | Size: 2.5 MB | Format:PDF | Quality:Unspecified | Publisher: NATIONAL INFORMATION CENTER OF EARTHQUAKE ENGINEERING Indian Institute of Technology Kanpur Kanpur (India) | Year: DECEMBER 2007 | pages: 90
This document is written for building professionals interested
in learning more about confined masonry construction and for
those who would like to promote its application in countries
without prior experience related to this construction practice.
Confined masonry has evolved over the last 100 years
through an informal process based on its satisfactory
performance in past earthquakes in countries and regions of
extremely high seismic risk. It is used both for non-engineered
and engineered construction; its field applications range from
one or two storey high single-family dwellings to six storey
apartment buildings. Design and construction provisions for
confined masonry are included in building codes in several
countries.
Building technologies are closely related to local conditions,
and their successful application depends on several factors,
including the availability and cost of building materials, the
skill level of construction labour and the availability of
construction tools and equipment. Introducing new
construction practices, or even improvements in existing ones,
can be daunting tasks. In India and many other countries,
masonry and reinforced concrete (RC) are the technologies of
choice for housing construction, with the design applications
ranging from one-storey family houses to multi-storey
apartment buildings. However, past earthquakes in India and
other countries have revealed weaknesses associated with
both masonry and reinforced concrete frame construction.
Confined masonry offers an alternative to both unreinforced
masonry and RC frame construction for applications in
earthquake-prone areas of the world. The fact that confined
masonry construction looks similar to RC frame construction
with masonry infills and that it uses the same components
(masonry walls and RC confining members) is expected to
assist in an easy transition from the construction perspective.
Confined masonry construction practice does not require new
or advanced construction skills or equipment, but it is
important to emphasize that quality construction and sound
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Line 1 of the ReLUIS 2005-2008 Framework Project consisted of a coordinated research on the evaluation and reduction of seismic vulnerability of existing masonry buildings. The research, which involved nineteen different research units, has developed along five main topics: the assessment and strengthening of structural units within building aggregates, the methods for assessment of mixed masonry-reinforced concrete structures, the strategies and techniques for strengthening of masonry buildings, considering both horizontal (floors, roofs, vaults) and vertical (walls) structural elements, the methodologies for modelling the seismic response of masonry structural systems. Within each topic several subtasks were considered, involving surveying, modelling, in-situ and laboratory testing. Within the project also some large scale static and dynamic testing was carried out, involving shake table tests on building models and structural components. In this paper the developments and outcomes of the project are synthesized.
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Seismic Analysis of a Typical Masonry Building from Barcelonaβs Eixample District
Author: Christopher Potter | Size: 5.2 MB | Format:PDF | Quality:Unspecified | Year: 2011 | pages: 154
The historic Eixample district of Barcelona is characterised by its beautiful avenues, laid out in grid across the city. At first impression, the buildings lining these avenues appear identical, an unending faΓ§ade built to house the new Barcelona of the 20th Century. The unreinforced masonry buildings that typify the development remain in use today, largely unaltered since their construction. Unreinforced masonry buildings are among the most vulnerable structures to damage from seismic actions. For the masonry buildings of the Eixample that house over 15% of the population of Barcelona, this is no exception. This study performs a seismic analysis on a typical masonry building of the Eixample to estimate and assess this damage. By doing so, it aims to estimate the likely damage due to seismic actions, to identify critical elements of the structures and to quantify the need for seismic risk maintenance and response plans.
The analysis uses the N2 Capacity Spectrum Method (Fajfar, 2000), adopted by Eurocode 8, to determine the displacement demand of possible earthquake scenarios. A seismic hazard analysis determines the seismic demand using deterministic, probabilistic and current European and Spanish code provisions. The seismic demand is then compared to the results of a non-linear pushover analysis completed using software DIANA (Version 9.4). The model geometry was based upon plans of a building that well represents the typical unreinforced masonry buildings of the Eixample.Results indicate a displacement demand to Spanish code provisions that corresponds to a substantial
level of damage, in accordance with the European Macroseismic Scale (EMS 98) damage criteria. A moderate level of damage is derived from the probabilistic seismic scenario. Similar to previous studies, these results indicate a significant risk of seismic damage. The analysis has isolated critical structural elements that control the global response and damage during seismic action. This information can be used to develop inspection and maintenance plans to limit the risk of seismic damage. This study highlights the real risk of seismic damage to the typical unreinforced masonry buildings of the Eixample district. It determines appropriate building maintenance procedures, and reinforces the
need for seismic response planning to best manage the significant expected social and infrastructure
demands should such a disastrous event ever occur.
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IDENTIFYING CONFIGURATION AND CONNECTION DETAILS OF UNREINFORCED MASONRY STRUCTURES IN MID-AMERICA
Author: Ty A. Stokes University of South Carolina REU at the University of Illinois at Urbana-Champaign Advisor: Professor Y. K. Wen | Size: 0.84 MB | Format:PDF | Quality:Unspecified | pages: 16
Experience from past earthquakes indicates that some structures perform better than others under similar ground motion conditions. This disparity leads to the conclusion that some structures will be safer, and thus less likely to require repair or cause harm, than others. In order to describe this phenomenon quantitatively, vulnerability functions are developed. Vulnerability functions describe a structure in terms of its likelihood (probability) of exceeding a certain limit state at a specified ground motion condition accounting for the uncertainty in both excitation and structural capacity. Indeed, there are several sources of uncertainty that cannot be eliminated, but in order to create the most accurate relationship possible, any uncertainty that can be reduced, should be reduced. Therefore, the goal of this particular part of this project is to remove some of the uncertainty in the nature of the buildings that are being modeled. By understanding better of a typical unreinforced masonry (URM) building, it is possible to accomplish this goal and create a vulnerability function which may better describe a larger percentage of the population of URM structures in
Mid-America.
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Behavior and Vulnerability of Reinforced Masonry Shear Walls
Author: Ehsan Minaie in partial fulfillment of the requirements for the degree of Doctor of Philosophy | Size: 18.6 MB | Format:PDF | Quality:Unspecified | Publisher: Drexel University | Year: august 2009 | pages: 488
The overarching goal of the research presented herein was to establish the key behavior mechanisms and seismic vulnerabilities of reinforced masonry (RM) shear walls. Currently, there are knowledge gaps related to partially grouted masonry shear walls, regarding their failure mechanisms, applicability of current code provisions to PG walls, and influence of bidirectional loading on the behavior of such walls. To bridge these gaps a research program that integrated both experimental and analytical approaches was conducted. The centerpiece of the experimental program was a series of full-scale, quasi- static cyclic tests of both PG and FG masonry shear walls. Key test parameters included the level of vertical stress, wall aspect ratio, and mortar formulation. Following these experiments a series of nonlinear finite element models were developed and correlated with the experimental results. These models were then used to examine the influence ofbi-directional loading through a series of parametric studies with out-of-plane drift, wall aspect ratio and vertical stress as variables. Results of this study indicated a potentially significant seismic vulnerability of PG masonry shear walls that is not reflected in current design provisions. The PG masonry shear walls tested displayed shear strengths less than half of the capacity estimated by current design methods. The modeling component of this research developed an efficient nonlinear finite element modeling approach that proved capable of simulating the capacity (within 10%), failure modes and hysteretic response of both PG and FG masonry shear walls. This modeling approach was also validated for the prediction of out-of-plane response, and then used to examine the bi- directional response of PG masonry shear walls. Results from this study indicated that out-of-plane drifts corresponding to the collapse prevention limit state may reduce the in- plane capacity of PG walls by more than 20%. Although the capacity of PG walls is influenced by out-of-plane drifts, their hysteretic responses, and in particular, energydissipation and ductility capacities remain nearly unchanged. As a result, the seismic response of PG masonry walls is likely only nominally affected by bi-directional ground motions.
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Article/eBook Full Name: IMPROVEMENT OF DYNAMIC PROPERTIES AND SEISMIC RESPONSE OF CLAY USING FIBER REINFORCEMENT
Author(s): Amir Faryar, Behzad
Edition: Dissertation
Publish Date: 2012
Published By: University of Maryland (College Park, Md.)
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(when trying to download the publication from the mentioned web site, I receive a notice saying "Restricted Access", but maybe there is someone not having the same problem - the thesis has been downloaded 50 times already)
Nonlinear phenomena should play a crucial role in the design and control of engineering systems and structures as they can drastically change the prevailing dynamical responses.
This book covers theoretical and applications-based problems of nonlinear dynamics concerned with both discrete and continuous systems of interest in civil and mechanical engineering. They include pendulum-like systems, slender footbridges, shape memory alloys, sagged elastic cables and non-smooth problems.
Pendulums can be used as a dynamic absorber mounted in high buildings, bridges or chimneys. Geometrical nonlinearities introduced by pendulum motion may change the system dynamics, and entail a rapid increase of the oscillations of both the structure and the pendulum, leading to full pendulum rotation or chaotic dynamics. To magnetorheological damping is proposed.
Nonlinear mechanics has to be used to explain undesired response in slender footbridges, such as that occurred in the famous event of the London Millenium Bridge. The observed phenomena can be explained by an analytical nonlinear discrete-time model.
Shape memory alloys (SMAs) exhibit very interesting nonlinear thermo-mechanical properties such as shape memory effect and superelasticity. SMA elements integrated within composite beams or plates can be used for active modification of structure properties e.g. by affecting their natural frequencies.
Finite amplitude, resonant, forced dynamics of sagged, horizontal or inclined, elastic cables have recently undergone meaningful research advances concerned with modelling, analysis, response, and nonlinear/nonregular phenomena. A variety of features of nonlinear multimodal interaction in different resonance conditions are comparatively addressed.
Non-smooth systems are very common in engineering practice. Three mechanical engineering problems are presented: (i) a vibro-impact system in the form of a moling device, (ii) the influence of the opening and closing of a fatigue crack on the host system dynamics, and (iii) nonlinear interactions between a rotor and snubber ring system.
This book is aimed at a wide audience of engineers and researchers working in the field of nonlinear structural vibrations and dynamics, and undergraduate and postgraduate students reading mechanical, aerospace and civil engineering.
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Contact mechanics is an active research area with deep theoretical and numerical roots. The links between nonsmooth analysis and optimization with mechanics have been investigated intensively during the last decades, especially in Europe. The study of complementarity problems, variational -, quasivariational- and hemivariational inequalities arising in contact mechanics and beyond is a hot topic for interdisciplinary research and cooperation. The needs of industry for robust solution algorithms suitable for large scale applications and the regular updates of the respective elements in major commercial computational mechanics codes, demonstrate that this interaction is not restricted to the academic environment. The contributions of this book have been selected from the participants of the CMIS 2009 international conference which took place in Crete and continued a successful series of specialized contact mechanics conferences.
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The Grouting Handbook: A Step-by-Step Guide for Foundation Design and Machinery Installation
Author: Donald M. Harrison | Size: 26.4 MB | Format:PDF | Quality:Unspecified | Publisher: Elsevier | Year: 2013 | pages: 222 | ISBN: 9780124165854, 0124165850
Minimize loss of revenue and the downtime of critical assets by avoiding foundation cracking, poor bonds, and initial alignment changes. After their successful introduction as a maintenance material, machinery grouts are now being used for equipment placement in new construction.
While certainly suitable for both markets and applications, a successful installation depends on proper grout selection, application, foundation preparation, and forming methods. Therefore, guidelines on their uses and limitations are needed for engineers and maintenance personnel.
Based on 45 years of field experience, The Grouting Handbook collects a vast amount of information into a practical and user-friendly reference for mechanical and civil engineers. The book focuses on four basic elements of grouting:
β’ The soil and its load-carrying capability;
β’ The foundation and its mass, design, concrete mix, installation and curing procedures;
β’ Anchor bolt technology, design and installation;
β’ Epoxy grout comparison, material selection and installation.
From the ground up, The Grouting Handbook takes you step by step through the grouting process. Clear, straightforward directions give you details on preparing the foundation and surface and selecting the best material and method. Comprehensive yet concise, this is a convenient handbook for veteran and rookie engineers alike.
β’ Organizes a comprehensive amount of information into an easy-to-use reference
β’ Provides advice for selecting the proper grouting material and method for the task at hand
β’ Contains tips and practical solutions for common problems
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