| Effect of the improved ground by deep mixing method is usually evaluated by unconfined compression tests of specimens bored from improved column to determine whether the results exceed the target strength of samples．However，when many cracks are found in collected samples，they can not be used for the unconfined compression test and a proper evaluation of strength may be difficult to obtain．Moreover，there is also an economic problem，that is，the cost of sampling specimens occurs．therefore，the present method to evaluate ground improvement should be reformed and a simpler in-situ method is expected to develop．［＊］In this paper，the authors seek to apply PS logging and the standard penetration test in order to realize in-situ strength evaluation of ground improved by deep mixing method． |
