| There are cases where the deep mixing method by column type improvement is used as foundation of box culverts constructed on peaty soft ground. However、 there are currently no appropriate design methods concerning ground-improvement width or ratio. This may lead to excessively safe specifications、 which make construction uneconomical in certain cases. A centrifuge model test was conducted、 to clarify rational design for the deep mixing method as foundation for box culverts. [*]The results showed that the desired performance could be obtained at an improvement ratio of even 30%、 if the stress of the improved column is smaller than the unconfined compressive strength of it. Sufficient improvement was also obtainable in the case where a width equal to that of the box culvert was set as the range of improvement、 and no deviations in stress acted on the box culvert. |
