Improvement Effect Evaluation of Low-Replacement-Ratio SCP Method with RI-CPT

This thesis describes the effect of ground improvement due to Low-Replacement-Ratio SCP Method. In this method, the replacement ratio is 30 to 50 percent. Because 70 percent of the consolidation layer is composed of unimproved clay, it is designed with taking account of increase in strength of clay. Therefore, it is required to grasp strength of clay between the improved piles accurately which enables to compare the stress sharing of sand and clay. In addition, the factor of safety against slip failure can be obtained. This thesis studies a case about measurement of circular slide and stress sharing ratio by strength and void ratio of clay measured with RI-CPT and its analysis flow. The case is Haneda Air Port D-RUNWAY Project.