Seismic Rehabilitation Methods For Existing Buildings

Seismic Rehabilitation Methods for Existing Buildings covers various structures, effective parameters in seismic improvement, and other factors in seismic loading in eight applied chapters with descriptive classification. The book offers guidance for a seismic rehabilitation project based on the interpretation of publications FEMA and Iranian seismic rehabilitation regulations no.360 . It includes real examples of completed and approved projects to stabilize the seismic improvement issues of existing buildings. Six perfectly executed examples, with complete refinement details, such as modeling, step-by-step improvement studies, and executive plans and seismic enhancement images are included. The book also explains the classification of non-structural element and how to carry out it's seismic reconstruction studies and in one of the chapters, construction and soil improvement methods are discussed along with a practical example.The concepts of seismic rehabilitation in this book are presented with an Info-graphic structure that better fixes the concepts in the minds of readers so that when they face a new project, they have a more practical use of the content Provides a fully functional way to evaluate, model and present details of a seismic rehabilitation plan for a building Presents real seismic refurbishment models and step-by-step methods for providing examples (including images, tables and charts)

Illustrated in full color throughout. The primary purpose of this document is to provide a selected compilation of seismic rehabilitation techniques that are practical and effective. The descriptions of techniques include detailing and constructability tips that might not be otherwise available to engineering offices or individual structural engineers who have limited experience in seismic rehabilitation of existing buildings. A secondary purpose is to provide guidance on which techniques are commonly used to mitigate specific seismic deficiencies in various model building types.

The present volume contains a total of 23 papers centred on the research area of Seismic Assessment and Rehabilitation of Existing Buildings. This subject also forms the core of Project SfP977231, sponsored by the NATO Science for Peace Office and supported by the Scientific and Technical Research Council of Turkey [ TUBIT AK ]. Most of these papers were presented by the authors at a NATO Science for Peace Workshop held in Izmir on 13 - 14 May, 2003 and reflect a part of their latest work conducted within the general confines of the title of the NATO Project. Middle East Technical University, Ankara, Turkey serves as the hub of Project SfP977231 and coordinates research under the project with universities within Turkey, e. g. Istanbul Technical University and Kocaeli University, and with partner institutions in Greece and the Former Yugoslav Republic of Macedonia: A few articles have also been contributed by invited experts, who are all noted researchers in the field. Altogether, the contents of the volume deal with a vast array of problems in Seismic Assessment and Rehabilitation and cover a wide range of possible solutions, techniques and proposals. It is intended to touch upon many of these aspects separately below. Earthquakes constitute possibly the most widely spread and also the most feared of natural hazards. Recent earthquakes within the first six months of 2003, such as the Bingol Earthquake in Turkey and the Algerian earthquake, have caused both loss of life and severe damage to property.

Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. The planning of changes to existing buildings differs from new planning through an important condition; the existing construction must be taken as the basis of all planning and building actions. The need for seismic retrofitting of an existing building can arise due to several reasons like: building not designed to code, subsequent updating of code and design practice, subsequent upgrading of seismic zone, deterioration of strength and aging, modification of existing structure, change in use of the building, etc. Seismic retrofit is primarily applied to achieve public safety, with various levels of structure and material survivability determined by economic considerations. In recent years, an increased urgency has been felt to strengthen the deficient buildings, as part of active disaster mitigation, and to work out the modifications that may be made to an existing structure to improve the structural performance during an earthquake. Seismic retrofitting schemes can be either global or local, based on how many members of the structures they are used for. Global Retrofit methods include conventional methods (increase seismic resistance of existing structures) or non-conventional methods (reduction of seismic demand). Strengthening and Retrofitting of Existing Structures is a compendium of cutting-edge trends of the research and existing practices in strengthening and retrofitting of structural elements, as well as the findings of a research endeavor initiated by the authors to investigate and develop a robust structural retrofitting scheme by utilizing elastomeric polymers to enhance the resistance of reinforced concrete (RC) structures. It addresses in detail specific techniques for the strengthening of traditional constructions, reinforced concrete buildings, bridges and their foundations. It also presents insight into the key issues relevant to seismic retrofit of concrete frame buildings. Many guidelines are reviewed regarding seismic rehabilitation of school, office, hospital and apartment buildings.

A considerable number of buildings in the existing building stock of the United States present a risk of poor performance in earthquakes because there was no seismic design code available or required when they were constructed, because the seismic design code used was immature and had flaws, or because original construction quality or environmental deterioration has compromised the original design. The practice of improving the seismic performance of existing buildings—known variously as seismic rehabilitation, seismic retrofitting, or seismic strengthening—began in the U.S. in California in the 1940s following the Garrison Act in 1939. This Act required seismic evaluations for pre-1933 school buildings. Substandard buildings were required to be retrofit or abandoned by 1975. Many school buildings were improved by strengthening, particularly in the late 1960s and early 1970s as the deadline approached. Local efforts to mitigate the risks from unreinforced masonry buildings (URMs) also began in this time period. In 1984, the Federal Emergency Management Agency (FEMA) began its program to encourage the reduction of seismic hazards posed by existing older buildings throughout the country. Recognizing that building rehabilitation design is far more constrained than new building design and that special techniques are needed to insert new lateral elements, tie them to the existing structure, and generally develop complete seismic load paths, a document was published for this purpose in 1992. FEMA 172, NEHRP Handbook of Techniques for the Seismic Rehabilitation of Existing Buildings (FEMA, 1992b), was intended to identify and describe generally accepted rehabilitation techniques. The art and science of seismic rehabilitation has grown tremendously since that time with federal, state, and local government programs to upgrade public buildings, with local ordinances that mandate rehabilitation of certain building types, and with a growing concern among private owners about the seismic performance of their buildings. In addition, following the demand for better understanding of performance of older buildings and the need for more efficient and less disruptive methods to upgrade, laboratory research on the subject has exploded worldwide, particularly since the nonlinear methods proposed for FEMA 273 became developed. The large volume of rehabilitation work and research now completed has resulted in considerable refinement of early techniques and development of many new techniques, some confined to the research lab and some widely used in industry. Like FEMA 172, this document describes the techniques currently judged to be most commonly used or potentially to be most useful. Furthermore, it has been formatted to take advantage of the ongoing use of typical building types in FEMA documents concerning existing buildings, and to facilitate the addition of techniques in the future. The primary purpose of this document is to provide a selected compilation of seismic rehabilitation techniques that are practical and effective. The descriptions of techniques include detailing and constructability tips that might not be otherwise available to engineering offices or individual structural engineers who have limited experience in seismic rehabilitation of existing buildings. A secondary purpose is to provide guidance on which techniques are commonly used to mitigate specific seismic deficiencies in various model building types. The goals of the document are to: Describe rehabilitation techniques commonly used for various model building types, Incorporate relevant research results, Discuss associated details and construction issues, Provide suggestions to engineers on the use of new products and techniques.