Question: How can we make buildings better able to resist earthquake damaged?

Asked by ipeleng to Anna, Daniel, Denise, Jesse, Rehemat on 13 Jun 2014.

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  1. Photo: Rehemat BhatiaRehemat Bhatia
    answered on 13 Jun 2014:

    Lots of ways!
    All unreinforced masonry structures made from clays or adobe (easily worked material; fire resistant, absorbs humidity and keeps buildings warm when mixed with water and a binder) can be altered to help resist earthquakes. Adobe houses have thick roofs which naturally weigh the structure down, so they collapse easily. Better materials to use would be strong, ductile and flexible; steel reinforcements would be more resistant because if they deform, the energy released is absorbed. The best sort of building would be one which has the maximum degree of flexibility, therefore reacting to side to side shaking well.
    Houses with smaller windows, more walls and which have additional structural frames of steel also tend to be resistant; if the frames are filled with stiff masonry brickwork then the design will fail. If the building is short, rigid and has a single storey it will respond rapidly to a lateral force. Buildings closer together tend to “pound” together, therefore in earthquake prone regions, buildings should be well spaced out to ensure this does not occur.
    On a smaller scale, raising buildings using stilts and tying struts together with ropes could all be suitable earthquake resistance solutions.
    The sites that buildings are built on should be thoroughly checked out to ensure that the land is stable. Geologists, structural and civil engineers can all help with this. Buildings should not be built on slopes, clays or soft land where liquefaction (when land turns into a water/jelly like state) could occur or near faults. Cross bracing can help buildings to resist shaking and reduce the impact of twisting; a uniform steel frame throughout the whole building along with deep foundations is also effective. Wood framed houses can be braced with plywood walls, attached to anchor bolts, which can be linked into the foundations 1 – 2 metres deep. In terms of tackling the effects of the tsunami, little can be done. Onshore tsunami walls at least 50m high could be built in the most prone coastal areas.

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  2. Photo: Daniel Lao DavilaDaniel Lao Davila
    answered on 14 Jun 2014:

    I agree with Rehemat’s answer. Buildings are made to support the vertical force exerted by gravity but not the sideways motion produced during earthquakes. Buildings that better resist earthquake damage are the ones that have flexible materials and support against the sideway motion.

    Now, this is an active area of research as engineers try to reduce damage from earthquakes, especially for those with large magnitude. Many old buildings would need to be retrofitted with new technologies, while new buildings in earthquake prone areas should be planned from the start with technology that reduce the earthquake damage.

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  3. Photo: Jesse DavenportJesse Davenport
    answered on 14 Jun 2014:

    I agree with Daniel and Rehemat and don’t really have anything to add mostly because I don’t know too much about geotechnical engineering. It is however, an extremely important topic for places such as the west coast of the United States, Japan, Indonesia, Oceania and many other places.

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  4. Photo: Anna RabittiAnna Rabitti
    answered on 15 Jun 2014:

    Hi ipeleng, very good question, and a very impotant one especially for an Italian, since in the terrible earthquake of L’Aquila in 2009 a lot of people died because the buildings were not made to resist an earthquake.

    Practically, buildings in seismic areas (as approximately the whole Italy is) should be able to resist vertical and/or lateral shaking, since earthquakes can induce both movements, according to the type of the generating fault and the type of ground where each specific building lies. If you want to build a new house some where, you can ask the municipality the seismic maps of the area: they will tell you which is the maximum earthquake you can expect in the area, the estimated recurrence time, the kind of motion you will have in case.
    Then you can proceed accordingly, as Rehemat explained in details, practically you would put your house on springs that can prevent the shacking and the destruction of the structure.
    Where do you live? you could check at your municipality the level of seismic risk associated to your city/village/province and check if your school is ready for an earthquake.
    I live on a muddy island, therefore earthquakes here are naturally dumped by the sand. Our biggest natural risk here is flooding!

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  5. Photo: Denise De GaetanoDenise De Gaetano
    answered on 15 Jun 2014:

    This was perfectly explained by the other scientist. I might add the following link: http://www.youtube.com/watch?v=Bg4kSIgn67I, a TEDX talk given by Ross Stein. I believe that it is one of the very best talks in relation to buildings being earthquake resistant. Hope it helps! 🙂

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