Abstract
A micro-bubble is an independent bubble of 10-100μm in diameter. A soil improvement method injecting the micro-bubbles into ground was newly developed, which may provide a cost-effective and a simple countermeasure method against soil liquefaction. Although it is well known that soil resistance to liquefaction increases as the saturation degree of the soil decreases, it has been difficult to lower the saturation degree of ground homogeneously. A technique using micro-bubbles, however, can be expected to solve the problem because the micro-bubbles can easily permeate into voids between sand particles.
In-situ applicability test in Ishikari, injecting water mixed with micro-bubbles was conducted. The test consisted of the injecting micro-bubbles into the ground and the liquefaction experiment by controlled blasting for improved ground. Based on these test results, the feasibility of the micro-bubble injection method were examined in the paper.
