Currently the seismic response of site is considered in structural design part of buildings (as a design spectrum). I want to know if there is not a specific soil improvement technique to mitigate the amplification effect?
Practically no, if not impossible. Generally, it would be more cheaper to strengthen the structure. Use of piles in soft soils may be beneficial due to kinematic interaction, but again it may be much cheaper to strengthen the structural system. You can consider installing base isolation if you do not have opportunity to enlarge the columns.
In 1921, Frank Loyd Wright designed the Imperial Hotel in Tokyo which was possibly the first building that used seismic isolation. There was an eight feet layer of fairly good soil lying over a layer of soft mud under the building site. This soft mud layer appeared to Wright as a good cushion to relieve terrible shocks. The building performed extremely well in the devastating 1923 Tokyo earthquake.
In the above line, some researchers have been working on effectiveness of layer of soft mud or fine sand between the building foundation and the hard stratum below in reducing the earthquake demands. Some shock table tests on masonry buildings constructed over layer of fine sand have been performed at IIT Roorkee and have shown the effectiveness of the methodology in mitigating a shock in comparison to a fixed base normal construction. Further, researches in having a layer of find sand mixed with shredded rubber are also done in order to get the effect of damping as well have also been performed.
However, a rational procedure for quantitative estimation of the effectiveness still has to be developed. Besides, many more experimental evidences are required to consider the effects like partial or complete saturation of the layer with ground water.
If at all rational procedures for the above type of seismic isolation are established, a very economical solution of mitigating earthquake forces will be made available.
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Cell Biology
- Culture Cells
- Cell Line