Analytical modeling for the behavior of concrete-cored cement mixing (CCM) pile composite foundation under embankment

The concrete-cored cement mixing (CCM) pile composite foundation is a practical technology for soft soil ground treatment. This paper proposed a theoretical analysis model for the CCM pile composite foundation under embankment in undrained condition which comprehensively considered the interaction between the various components of the CCM pile composite foundation. The working behavior and influencing factors of CCM pile composite foundation under the embankment was also investigated based on the proposed analysis model. The research results showed that: the embankment load was transferred from the outer soil column to the inner soil column. The formation of soil arch effect promoted the concrete core pile to undertake the majority of embankment load, which improved the working behavior of the CCM pile composite foundation under flexible foundation. There was a neutral plane at a certain depth below the ground surface, and the pile shaft above the neutral plane was under negative skin friction, moreover, the vertical stresses of the concrete core pile, cement mixing pile and the soil around the pile all reached the maximum value at the neutral plane.