Seismic interactions

Seismic interactions are physical interactions of structures, distribution systems, mechanical or electrical components with nearby safety related structural systems or equipment components, caused by an earthquake. 

The seismic interaction effects that can be considered during the design/ re-evaluation process are  

Proximity (impacts of adjacent equipment or structures on safety related equipment due to their relative motion during an earthquake)  

Structural failure and falling of overhead or adjacent structures, systems and components  

Flooding due to earthquake induced failures of tanks or vessels  

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POTENTIAL SEISMIC INTERACTION INVOLVING THE MOVABLE INCORE FLUX MAP SYSTEM AT WESTINGHOUSE PLANTS... 

The goal of this approach to qualification is to ensure that the as installed items are capable of withstanding the design basis seismic effects without loss of structural integrity, with account taken of anchorage effects and seismic interaction effects (on items and operators). 

A seismic interaction is an interaction initiated by an earthqnake that leads to influences between items or between an item and the operator that conld impair their capability to perform their assigned safety function. Interactions may be mechanical (hammering, impact, wear and explosion), chemical (release of toxic or asphyxiant substances), radiological (an increase in dose) or by means of an earthquake induced fire or flood. 

EH 2 Need for assessment of seismic interaction of structures or equipment on safely functions (France, India, Japan, Republic of Korea, USA)... 

Currently, qualification methods based on experience are available primarily for seismic design and seismic re-evaluation of equipment [37-39]. Earthquake experience methods are simple and efficient tools to verify the seismic adequacy of selected mechanical, electrical and instriunentation and control equipment classes. Earthquake experience methods are also used to verify the seismic adequacy of piping, anchoring of piping supports and masonry walls, and to check potential seismic interactions. These methods are primarily screening and waUcdown procedures and are summarized in Appendix III. Some of them involve establishing the similarity of candidate items to reference items. Similarity requires both the following basic conditions ... 

Practical approaches on how to avoid such seismic interactions and how to protect items important to safety are given in Refs [43-46],... 

DOE procedure Selected mechanical and electrical equipment classes Cable supporting structures Anchoring of equipment Non-bearing brick walls Architectural details Seismic interactions [39]... 

The Seismic Safety Margins Research Program developed a computer code called SMACS (Seismic Methodology Analysis Chain with Statistics) for calculating the seismic responses of structures, systems, and components. This code links the seismic input as ensembles of acceleration time histories with the calculations of the soil-structure interactions, the responses of major structures, and the responses of subsystems. Since uses a multi-support approach to perform the time-history response calculations for piping subsystems, the correlations between component responses can be handled explicitly. SMACS is an example of the codes that are available for calculating seismic response for PSA purposes. 

It is increasingly apparent that there are exchanges and interactions between all the major chemical domains within the silicate earth. Communication between the upper mantle and cmst occurs at ridges, above mantle plumes, and at volcanic arcs. Geochemical smdies of OIBs, as well as seismic tomography of mantle stmcture beneath subduction zones demonstrate that there is... 

While the present discussion is concerned with the interaction of two commensurate walls only, similar dilatancy effects occur under more general circumstances. Indeed, dilatancy is expected in a broad range of systems where coupling between lateral and normal directions exists. Recently this phenomenon has been intensively studied in the context of sheared granular media [226,246,252] and seismic faults [253,254]. The observation of dilatancy is limited by the choice of the normal spring, which should be weaker than the potential elasticity, Uq. From the dependence of the dilatancy AZp on... 

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