seismic design of structures.

Replies

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  CIVILPRINCESS

  When we speak of seismic design of structures, we mostly speak of the modern methods.
  Two basic technologies are used to protect buildings from damaging earthquake effects. These are Base Isolation Devices and Seismic Dampers.
  
  let us have a detailed idea about the base isolators first.
  
  BASE ISOLATION:
  The idea behind base isolation is to detach (isolate) the building from the ground in such a way that earthquake motions are not transmitted up through the building or at least greatly reduced. A base isolated structure is supported by a series of bearing pads, which are placed between the buildings and building foundation. The bearing is very stiff and strong in the vertical direction, but flexible in the horizontal direction.
  
  
  
  the closer look at the rubber bearings will be as follows:
  
  
  
  
  A lead–rubber bearing is made from layers of rubber sandwiched together with layers of steel. In the middle of the bearing is a solid lead "plug." On top and bottom, the bearing is fitted with steel plates which are used to attach the bearing to the building and foundation. The bearing is very stiff and strong in the vertical direction, but flexible in the horizontal direction.
  
  in the next post i will brief you about the spherical isolating system.
• 

  NKuzmick

  This is a great post on the usefulness of rubber bearings in building safety design - I thought I'd give it a bump.
  
  I also recently came across some good literature about this topic courtesy of #-Link-Snipped-#
  
  In issue 13 of their natuurrubber publication from 1999 they discuss the uses of natural rubber in building design in depth - it's a pretty informative article
  
  To find the article online go to the newsletter tab and click on #13 - that will load the PDF of the newsletter.
  
  Cheers
  
  Nick Kuzmick
  Timco Rubber Products
  Custom Rubber Products & Parts Supplier | Timco Rubber
  #-Link-Snipped-#
• 

  theconstructor

  I have got something to share. visit #-Link-Snipped-# for earthquake related design guide. there is nothing complicated there, just small things that we should keep in mind while designing a building so that it does not collapse during earthquake..
  
  I hope you will find it useful.
• 

  CIVILPRINCESS

  Spherical Sliding Isolation Systems
  
  Spherical Sliding Isolation Systems are another type of base isolation. The building is supported by bearing pads that have a curved surface and low friction.
  During an earthquake, the building is free to slide on the bearings. Since the bearings have a curved surface, the building slides both horizontally and vertically. The force needed to move the building upwards limits the horizontal or lateral forces which would otherwise cause building deformations. Also, by adjusting the radius of the bearing's curved surface, this property can be used to design bearings that also lengthen the building's period of vibration.
  
  the following is a picture of spherical isolating structure :
  
  
• 

  gohm

  What are the pros & cons of the two systems discussed so far and what applications are they best suited for in building design?
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  CIVILPRINCESS

  though both these satisfy the need, people mostly use only lead rubber bearing in practical application since it is cheap and also easily fixed. but the only disadvantage of lead rubber bearings is that the middle layer of lead gets damaged after some quakes. so it will require maintenance.
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  maria flor

  I'm a 3rd yr. civil engineering student. I just want to ask what is the difference between a roller or hinge and how can we create a roller or hinge in actual.
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  CIVILPRINCESS

  hinge is actually a type of connection in the beams and structures that restrict movement right? the rollers support but they allow movement. that the difference i guess. 😀
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  maria flor

  Do rollers really gives freedom to columns and beams to expand and contract during hot or cold temperature???
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  maria flor

  What is this energy dissipation devices???
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  Nachko

  Only hinges here. I have made these photos in Budapest, Amsterdam and Berlin.
  And yes, rollers really allow expansion and contraction 😀
  
  
  Oops! On the fifth photo from the top you can see a kind of a roller - a thick lead plate that allows side movement - not too big, but enough to be considered a "roller" type. The lead plates are old fashion, now polymers or real rollers are used.
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  Prerna Singh

  the traditional methods discussed include one of the structure called the KOTI BANAL in uttarakhand.these structures are standing for the past 500 years n are made using timber n stone rubble masonry.....
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  Kaustubh Katdare

  Interesting - what makes these houses so strong?