Masonry Construction In Active Seismic Regions

During earthquakes, masonry buildings are the most affected, and consequently, damage to these buildings leads to massive loss of life and property. Masonry buildings comprise probably the greatest share of overall housing stock, and in turn, understanding their performance during earthquakes is a pivotal problem in seismic regions. Masonry Construction in Active Seismic Regions presents details on the kinds of masonry building found in seismic regions of the world. The title describes interventions, such as retrofitted solutions, dynamic identification, and improved construction after earthquakes, that are equally applicable to regions of moderate and high seismicity. The book covers representative masonry buildings from active seismic regions, the material properties of masonry construction, numerical modelling techniques and computational advances, seismic performance of non-engineered masonry buildings, resilience in typical construction, retrofitting, and the cultural values and structural characterization of heritage masonry buildings in active seismic regions. This book is unique in its global and systematic coverage of masonry construction in seismic regions. Identifies the material properties of masonry construction from a seismic perspective Covers representative masonry buildings from active seismic regions, providing a benchmark to understand existing building stocks Provides numerical modelling techniques and reviews computational advances, including a large test database Details the seismic performance of non-engineered masonry buildings, as well as the cultural values and structural characterisation of heritage masonry constructions Analyses typical or vernacular constructions which have earthquake resilient features, such as Dhajji-Dewari, Borbone, Pombalino, and Himis

In the last few decades, a considerable amount of experimental and analytical research on the seismic behaviour of masonry walls and buildings has been carried out. The investigations resulted in the development of methods for seismic analysis and design, as well as new technologies and construction systems. After many centuries of traditional use and decades of allowable stress design, clear concepts for limit state verification of masonry buildings under earthquake loading have recently been introduced in codes of practice. Although this book is not a review of the state-of-the-art of masonry structures in earthquake zones, an attempt has been made to balance the discussion on recent code requirements, state-of-the-art methods of earthquake-resistant design and the author's research work, in order to render the book useful for a broader application in design practice. An attempt has also been made to present, in a condensed but easy to understand way, all the information needed for earthquake-resistant design of masonry buildings constructed using traditional systems. The basic concepts of limit state verification are presented and equations for seismic resistance verification of masonry walls of all types of construction, (unreinforced, confined and reinforced) as well as masonry-infilled reinforced concrete frames, are addressed. A method for seismic resistance verification, compatible with recent code requirements, is also discussed. In all cases, experimental results are used to explain the proposed methods and equations. An important part of this book is dedicated to the discussion of the problems of repair, retrofit and rehabilitation of existing masonry buildings, including historical structures in urban centres. Methods of strengthening masonry walls as well as improving the structural integrity of existing buildings are described in detail. Wherever possible, experimental evidence regarding the effectiveness of the proposed strengthening methods is given. Contents:Earthquakes and Seismic Performance of Masonry BuildingsMasonry Materials and Construction SystemsArchitectural and Structural Concepts of Earthquake-Resistant Building ConfigurationFloors and RoofsBasic Concepts of Limit States Verification of Seismic Resistance of Masonry BuildingsSeismic Resistance Verification of Structural WallsMasonry Infilled Reinforced Concrete FramesSeismic Resistance Verification of Masonry BuildingsRepair and Strengthening of Masonry Buildings Readership: Practising engineers and students.

Building structures using masonry is one of the most widely adopted construction practices. However, its seismic performance in earthquake prone regions is a major concern. Majority of the research work which has been carried out for studying the failure pattern of masonry, either targets in-plane failure or out-of-plane failure of walls. However, various survey reports on the damage caused by earthquakes mention about failure of the corner walls of masonry structures such as those situated at the end of a row of structures, in a peculiar manner. Failure in such walls is characterized by the simultaneous overturning of a portion of orthogonal walls which is possible only if lateral loads act along the corners, implying each corner wall is subjected to bidirectional loading. Since the literature addressing such failure, are limited, therefore this study has been carried out to explore the reasons leading to corner failure of masonry structures.In this study, in order to examine the failure pattern at corner in dry masonry structures, finite element (FE) technique was adopted. Various masonry models with varying vertical load were subjected to dynamic loading along the corner to observe their combined effect on failure pattern. This analysis showed the pattern of propagation of crack through the bed joint along under varying dead load conditions. Since it is not possible to perform FE analysis for all the masonry structures, mathematical relations were derived to calculate the limiting acceleration at which corner failure can occur. These relations were obtained by assuming feasible failure mechanisms and applying the concept of limit state analysis. For studying the failure pattern of corner in mortar bonded masonry, the FE approach adopted for dry masonry was extended. Micro-modelling which is mostly adopted for modelling mortar bonded masonry was modified by introducing the concept of equivalent friction to simulate the behaviour of mortar in shear. Cracks were observed to pass through the bricks along with the bed joints which lead to toe crushing due to overturning of failure portion. Through this study an understanding of failure of the corner has been developed.

Many traditional masonry buildings are exposed to high intensity earthquakes where the collapse of masonry claims the majority of casualties. This workshop provided a forum for discussion, including survey and measurement, retrofitting criteria and approaches used in different European countries.

This monograph 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 with high earthquake risk. Confined masonry has evolved over the last hundred 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- and two-storey single-family dwellings to six-storey apartment buildings.