If retrofitting of column and other members alone is not sufficient, or if an improvement in the performance of the entire bridge structure is desired, in some cases seismic isolation and other retrofitting as a structural body, foundation retrofitting, or various bearing retrofitting methods are combined with this method. Selecting the appropriate treatment strategy is a great challenge involved in the retrofit process and must be determined individually for each project. Over the most recent two decades, numerous seismic retrofitting methods for unreinforced masonry structures have been widely used. Conventional as well as emerging retrofit methods are briefly presented in the following subsections. Waghmare address for correspondence acharya shrimannarayan polytechnic,piprim, wardha maharashtra abstract seismic protection of buildings is a needbased concept aimed to improve the performance of any structure under future earthquakes. Assessment of seismic retrofitting techniques of rc. These draft guidelines for retrofit cover the retrofitting of structures using the external cable method, the bonding and jacketing method, and the overlaying and jacketing methods, based on existing technologies. There are a variety of commercial seismic retrofitting methods. In the past thirty years, moderate to severe earthquakes occurs around the world every year.
Such events lead to damage to the concrete structures as well as failures. Seismic assessment and retrofit design masonry infills. Modern methods for seismic retrofitting of existing buildings seismically vulnerable. Pdf retrofitting is a process that is used to improve the strength, durability and performance of the structure. Tiebracing method does not provide the required integrity and strength. Advanced design examples of seismic retrofit of structures provides insights on the problems associated with the seismic retrofitting of existing structures.
Once the decision is made, seismic retrofitting can be performed through several methods with various objectives such as increasing the load, deformation, andor energy dissipation capacity of the structure conventional as well as emerging retrofit methods are briefly presented in the following subsections. Here we will introduce two methods of seismic retrofitting. Calculated cutoff values cv for the different preliminary assessment methods 92 table 6. Procedure for prioritization of methods for seismic retrofitting of structures in this procedure, different seismic retrofit methods, which are designed for a given structure, are prioritized considering both seismic and nonseismic criteria. In 1990 the gci initiated two projects to research. Seismic retrofitting definition, techniques using modern. We have links to resources that can help ensure that you do the work properly.
After briefly introducing how seismic action is described for design purposes, methods for assessing the seismic vulnerability of existing buildings are presented. Some of these methods were practically implemented and procedures are illustrated using a case study of four storey rc building retrofitted for a moderate. Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. However, today there are methods of reducing the risk of earthquake damage. Seismic stabilization of historic structures 19901996.
This manual has six main chapters and eight appendices. Methods and details of seismic retrofitting of bridge abutments are discussed. Seismic retrofitting definition it is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. I accidentally came across these useful case studies, which, i would like to share.
Seismic retrofitting techniques are required for concrete constructions which are vulnerable to damage and failures by seismic forces. You can use them if you are working on a commercial or residential building retrofitting project. Research article materials and jacketing technique for retrofitting of structures shri. The concrete layer method is the most invasive and the least costeffective.
The first, the getty seismic adobe project gsap, investigated alternatives to existing retrofitting methods. Review of retrofitting technique of unreinforced masonry. Considering the suitability of these methods in terms of material availability, beneficiaries level of. The principles and practice of effective seismic retrofitting this is a very rough draft of a book on retrofitting being written by howard cook in collaboration with structural engineers who are members of the structural engineers association of northern california. Once the decision is made, seismic retrofitting can be performed through several methods with various objectives such as increasing the load, deformation, andor energy dissipation capacity of the structure. Several years before that event, the gci had actually embarked on a program of seismic retrofitting research, with a focus on built cultural heritage.
Advanced design examples of seismic retrofit of structures. Two types of abutments used in bridge construction, monolithic and seat type. The retrofit techniques are also applicable for other natural hazards such as tropical cyclones, tornadoes, and severe winds from thunderstorms. Manual on retrofitting of existing vulnerable school buildingsassessment to retrofitting part i i preface schools are institutions providing an education as well as a common place for community gatherings and meetings. Evaluation methods lesson 2 seismic ground motion hazards and geotechnical hazards develop response spectrum di g t h i l h d i l di li f tidiscuss geotechnical hazards including liquefaction lesson 3 retrofitting methods for superstructures lesson 4lesson 4 retrofitting methods for substructuresretrofitting methods for. Seismic retrofitting of bridge abutments methods and details. It is being written to help contractors and engineers. The authors present various international case studies of seismic retrofitting projects and the different possible strategies on how to handle complex problems encountered. Seismic retrofit of columns using basalt mesh reinforced.
Seismic vulnerability assessment of bridges for retrofitting and new design by pedram farokh thesis director. Seismic retrofitting techniques for concrete structures. The retrofitting techniques for various portions of bridge are described below. First, the sill plate can slide off of the foundation. Commercial seismic retrofitting california foundation works. There are many wellknown seismic retrofitting techniques for structures. Review of retrofitting methods to reduce seismic vulnerability of buildings, with particular reference to hospitals and medical facilities dina dayala, carmine galasso, stylianos minas and viviana novelli june 2015. Pdf retrofitting of existing rcc buildings by method of. Husam najm many bridges in north eastern region of u. Information on techniques and methods behind effective. Study on various methods and techniques of retrofitting. Rehabilitation and retrofitting of structures notes rrs. Methods for structural seismic retrofitting of hospital buildings 2.
Energy absorption bracing with lowyieldpoint steel. The retrofitting of bridge may be required in each of the components. Retrofitting of existing rcc buildings by method of jacketing chapter 1 introduction 1. Highlights three different methods of seismic retrofitting jack arch slabs are investigated. Example 1 is an examination of retrofitting using eab.
Application of repair methods is expected to restore the structures to its preearthquake condition where as application of retrofitting methods to damaged structures is expected to increase strength and ductility of the structure. Retrofitting construction work items and current unit prices 111 table 6. For example, seismic retrofitting is generally used for column members and is performed in most cases to improve safety and restorability. It needs to evaluate several possibilities in relation to other aspects of the hospitals management and use. These techniques can be categorized into two groups 1. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. In 1990, the getty conservation institute initiated two projects to research and develop methods to provide seismic stabilization for historically and culturally significant buildings located in earthquake regions. Seismic vibration control and base isolation retrofitting. Strategies and collection of examples in switzerland foen 2008 10 1 dealing with existing structures in recent years the seismic requirements in building standards have been getting distinctly more rigorous. Earthquake retrofit faqs sound seismic retrofitting faqs.
Th ose factors include retrofi t costs and the economic viability of older existing buildings, the number of occupants and type of use of the buildings, and the historic or architec. Seismic retrofitting techniques for concrete structures focuses procedures to improve evaluation of seismic vulnerability of reinforced concrete buildings and provide innovative retrofitting techniques such as base isolation and mass reduction. Study on methods and techniques of retrofitting ijert. Fhwa seismic retrofitting of highway truss bridges by w. The retrofit process is a general term that may consist of a variety of treatments, including. Pdf modern methods for seismic retrofitting of existing. They should be models in providing examples of quality education and the. The approach taken depends on your type of structure. Retrofitting upgrading of certain building systems existing structures to make them more resistant to seismic activity earthquake resistance structures can be earthquake damaged earthquake vulnerable retrofitting proves to be a better economic consideration and immediate shelter to problems rather than replacement of building.
Important educational downloads about earthquake retrofitting. Six ways to protect your home from flooding, provides information that will help you decide whether your house is a candidate for retrofitting. These case studies provide insight about seismic retrofitting and also on analytical methods, that are used for bui. This chapter gives a basic overview of the different flood retrofit options. The presentation is illustrated by case studies of actual buildings where traditional and innovative retrofitting methods have been applied. Homes tend to fail in one of three ways all between the foundation and the first floor joists. The twoway steel grid method is less invasive and the most costeffective. The extent of retrofitting will be based on detailed seismic assessment following dynamic methods of analysis. The retrofitting is examined with an application to a 64m highrise src steel framed reinforced concrete. Each of these documents contains technical and engineering information that we have found indispensable in our designs and installation residential seismic retrofits. The city of seattle sometimes teaches classes for homeowners on the basics of seismic retrofitting, as does the phinney neighborhood association.
Research article materials and jacketing technique. This may make them vulnerable to damage or destruction in earthquakes. Health monitoring of structures use of sensors building instrumentation. Strengthening of structures strengthening methods retro. Seismic retrofit of columns using basalt mesh reinforced sprayed grc jacket page 6 of 7 conclusions in this study, a new and practical seismic retrofitting method is presented and general information is given about the materials and application procedures of the proposed retrofit approach. The seismic retrofitting of reinforced concrete buildings not designed to withstand seismic action is considered. Reference rehabilitation and retrofitting of structures rrs notes pdf rrs pdf notes rrs pdf rrs notes.
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