Microbes Can Steady Buildings against Earthquakes

Filed in archive Energy, Environment and Ecology , Microbiology on February 24, 2007

A natural soil bacterium called Bacillus pasteurii can be used to steady buildings against earthquakes.

These microbes (together with additional nutrients and oxygen) can turn a sand pile into sandstone by causing calcite (calcium carbonate) to be deposited around sand grains, cementing them together.

This new process has been tested in a laboratory scale by researchers at UC Davis and found that they could turn loose, liquefiable sand into a solid cylinder.

According to Jason DeJong, an assistant professor of civil and environmental engineering at UC Davis:

"When a major earthquake strikes, deep, sandy soils can turn to liquid, with disastrous consequences for buildings sitting on them.

Currently, civil engineers can inject chemicals into the soil to bind loose grains together. But these epoxy chemicals may have toxic effects on soil and water."

This new method (if successful on a large scale) is potentially less toxic than chemical methods.

[The treatment could be done after construction or on an existing building, and the structure of the soil is not changed -- some of the void spaces between grains are just filled in.]

The UC Davis team is now working on scaling up the process and scourging for funds to be able to test the method in the earthquake-simulating centrifuge at UC Davis' Center for Geotechnical Modeling.

Source: UC-Davis News