Stiffened deep cement mixing (SDCM) pile are gaining popularity in civil and architectural engineering due to their combination of core pile advantages

such as high axial load transfer ability

and deep mixing column advantages

such as high side friction. SDCM piles offer high construction efficiency

high bearing capacity

and lower costs. However

the existing calculation methods for determining their bearing capacity often differ significantly from actual test results due to a lack of unified understanding regarding their load transfer mechanism. To address this

full-scale field tests of SDCM piles embedded in silt were conducted to study the compressive bearing characteristics and load transfer mechanism. Ordinary cement and gypsum-slag soil hardening agent were both used as the binder materials in SDCM pile. The pile load-displacement curves were measured

and the ultimate bearing capacity of a single SDCM pile under compression was analyzed. The influence of binder materials was also checked. Coring tests were conducted to obtain its unconfined compressive strength (UCS). The discreteness of UCS between the field mixing cemented soil and the laboratory test were also analyzed. A three-dimensional elastoplastic finite element numerical model considering the interfaces of core pile-cemented soil and cemented soil-in-situ soils was established. The distribution of axial force along pile shaft and the shear stress between contact surfaces under different loads applied to the pile head were explored. The load transfer mechanism was analyzed and the higher bearing capacity compared with bored piles were discussed. The results show that the ultimate compressive bearing capacity of the SDCM pile in silt is larger than 1.5 times the sum of the compressive bearing capacity of the pure deep mixing pile and the single core pile. As the end resistance takes effect and increases

the shear deformation between the core pile and the cemented soil at the pile tip will increase rapidly due to the axial compression of the cemented soil. Thus

this position is prone to shear failure. Compared with traditional bored piles

the improvement of the bearing capacity the SDCM pile is mainly due to the interface improvement caused by solidification.