Natural disasters come in all varieties, and earthquakes are among those that impose the most serious of threats. One of the phenomena associated with earthquakes involves a process known as soil liquefaction, which occurs when wet, loose soil is vigorously shaken. And this occurrence can culminate in catastrophic effects when such soils support various structures.
While protection from earthquakes is needed throughout the world, Oregon has several oil tanks located along its Willamette River. For this reason, a team of researchers is investigating new ways to prevent soil liquefaction related to earthquakes. And their approach to this pursuit is one that is not only interesting but incredibly inexpensive as well.
Understanding and Preventing Soil Liquefaction
Soil liquefaction is quite an interesting phenomenon that can occur during a major earthquake. In essence, soil that is rather loose and has poor structural integrity is prone to absorb water. When a major earthquake hits, the shaking that ensues essentially invites this phenomenon to occur. Thus, rather than remaining more solid in nature, the soil “liquefies” resulting in an inability to support other structures. Naturally, this case can result in devastating effects depending on the structures present.
In the past, engineers have attempted protection from earthquakes and soil liquefaction through an array of strategies. Specifically, stone columns have been added to soils, or grouts have been infused. Other techniques have also included “pounding” the soil to make it less loose and more compact. While all these help with protection from earthquakes, they are costly and not necessarily environment-friendly. For these reasons, engineers are seeking better ways to prevent soil liquefaction and reduce the impacts this occurrence can cause.
A Novel Approach to Preventing Soil Liquefaction
Efforts to discover newer and better ways for protection from earthquake effects are still perpetually being pursued. In Toronto this past year, researchers tested a way to enhance calcium carbonate production in soils to reduce soil liquefaction. While this attempt failed, the process did leave the soil aerated and less saturated with water. As a result, it prompted researchers to consider a new way of preventing soil liquefaction through gas-forming microorganisms.
The current research now being explored involves injecting the soil with microorganisms that produce nitrogen and carbon dioxide gases. Once these gas bubbles exist in the soil, they might prevent water from gaining access during earthquakes. In other words, this re-engineering of soil at a molecular level could deter soil liquefaction completely. And given that it’s eco-friendly and 20 times less expensive, this form of protection from earthquakes could be revolutionary.
A Potential for Protection from Earthquakes Worldwide
For Oregon, the relevance of this research in deterring soil liquefaction is critically important. Currently, 90 percent of Portland’s oil supply resides in tanks along the Willamette River. The 62 acres upon which these tanks occupy are areas prone to soil liquefaction if a major earthquake occurs. Notably, such a case would create the potential for a major environmental disaster, and would, similarly, prevent ease of access to needed fuel during a time of crisis. This fact is one reason the current testing of this new “superdirt” is being performed in the Portland region.
Should this new method of protection from earthquakes prove to be effective, its potential for use globally should be noted. Trillions of dollars of infrastructures could be more readily protected from the effects of soil liquefaction. Likewise, the administration of the microorganisms that deter soil liquefaction is noninvasive and eco-friendly. Therefore, the results of the current research are being monitored with great anticipation. If found effective, this bold and innovative approach could completely change the way we employ methods or systems of protection from earthquakes in the future.