UC Davis scientists use bacteria to fight earthquake liquification
Application of Bacillus pasteurii during or after construction creates a shell of calcium carbonate around sand grains; approach avoids use of dangerous chemicals; funding required for larger studies
During the 1989 Loma Prieta earthquake in San Francisco, much of the destruction was caused by what seismologists call liquification — the tendency of sand and landfill to give way almost immediately under the earthquake’s vibrations. Preventing liquification is among emergency planners’ most pressing concerns, and it has long been known that one way to do so is to inject chemicals into the loose ground soil in order to bind the material together. The neccesary chemicals, however, are extremely toxic, and as liquification is likely to take place near coastlines, such an approach is unappealing to many.
Fortunately, scientists at our alma mater the University of California at Davis (go Aggies!) have discovered a benign bacteria — Bacillus pasteurii — that accomplish the same goal. “Starting from a sand pile, you turn it back into sandstone,” said professor Jason DeJong, explaining that the bacteria binds with oxygen and other nutrients to form a calcium carbonate shell around grains of sand, thereby cementing them together. The process, which has also been used to repair statues, could be applied during or after construction. With proper funding, DeJong and his colleagues intend to undertake a larger study of the issue.
-read more in Robert Roy Britt’s LiveScience report
