Crushed Stone
Boreholes were drilled to examine the depth of the crushed stones after soil improvement. One of the borehole logs is shown in Fig. stones were found to be present up to 9 m, in which the top 5 or 6 m was densely packed, whereas the remaining 4 or 5 m was embedded in the crushed stone layer were a silty gravel layer and the weathered sandstone layer.