The unanticipated brittle fracture of connection of the steel moment resisting frame (SMRF) occurred in 1994 the Northridge earthquake. Since then, the researches for the vulnerability of connection of the existing SMRF and for rehabilitation of those buildings were conducted. This paper suggests performance-based optimal seismic retrofit technique using connection upgrade. For optimal design, ...

many old damaged and undamaged building structures do not meet the criteria of modern seismic design codes. such structures need to be seismically enhanced. the main objective of this paper is to propose and validate the effectiveness of an upgrade scheme for non-seismic buildings using steel plate shear walls (spsw). the upgrade is carried out considering a probability-based drift-based criter...

Many RC frames built without seismic provisions between the ’50’s and ’70’s need structural upgrade in order to match the minimum requirements of new building codes. Generally, the critical region of the strengthening design is represented by the beam-column connection. The strength hierarchy governs the upgrade requiring to protect the column and the panel so that the formation of a plastic hi...

 Many existing bridges were designed without adequate consideration of seismic risk. The full or partial collapse of even one major bridge in a city or community would have destroying results. There has been focuses on developing fragility-based seismic vulnerability of existing usual bridges in Iran or support decision making on seismic upgrade. This article focuses on developing performance b...

Seismic retrofitting of under-designed structures is a consolidated approach to risk management. Several options are available for the achievement of the vulnerability reduction goals, each of those having peculiar performances in respect of different technical and non-structural criteria. Selection of the best solution is a non-trivial task, because criteria may conflict each other. MultiCrite...

to increase the safety of structures against strong ground motions and their life due to environmental issues on the earth and saving in terms of materials, it is necessary to expand and upgrade seismic resistant systems. however, more cost-effective systems which have sufficient influence on the seismic performance of structures and also more compatibility with the regional conditions, will be...

The baseline design concept for a seismic isolation component of the proposed “Advanced LIGO” detector upgrade has been developed with proofof-principle experiments and with computer models. It consists of a two-stage in-vacuum active isolation platform that is supported by an external hydraulic actuation stage. Construction is underway for prototype testing of a full-scale preliminary design.

Many opportunities are becoming available for using composite materials to strengthen/upgrade existing reinforced concrete (RC) structures. This paper focuses on a new technique for the seismic upgrade of RC beam-column connections in gravity load-designed (GLD) frames by the application (combined or not) of FRP rods and laminates. The FRP rods provide flexural strengthening, whereas the lay-up...

Supplementary energy dissipation has proved to be an effective way of protecting structures from the disastrous effects earthquakes and been used in last decades both new existing constructions. In this regard, various procedures for design damping system seismic retrofit buildings have formulated over years, mainly focused on reinforced concrete (RC) constructions, which represent largest part...

A seismic isolation system for the proposed 'Advanced LIGO' detector upgrade is under development. It consists of a two-stage in-vacuum active isolation platform that is supported by an external hydraulic actuation stage. A full-scale preliminary-design technology demonstrator of the in-vacuum platform has been assembled and is being tested at Stanford's engineering test facility. Unanticipated...