A dual-interface load transfer model for precast concrete-cored cemented soil piles considering progressive damage

Area of Science:

• Geotechnical Engineering
• Civil Engineering
• Materials Science

Background:

• Precast concrete-cored cemented soil piles (PCCS) enhance soft ground bearing capacity.
• Existing models neglect interface damage, leading to inaccurate predictions.
• Progressive interface damage under load affects PCCS performance.

Purpose of the Study:

• To develop a dual-interface load transfer model for PCCS.
• To explicitly simulate progressive interface damage between components.
• To improve the accuracy of bearing capacity predictions for PCCS.

Main Methods:

• Coupling an exponential damage model for the inner interface with an elastoplastic model for the outer interface.
• Calibrating the inner interface model using direct shear tests.
• Employing a convergent iterative algorithm to solve governing equations.
• Validating the model with field measurements from a test pile.

Main Results:

• The proposed model accurately predicts PCCS bearing capacity, validated by field data.
• The concrete core sustains over 90% of the pile-head load.
• A distinct C-shaped axial force distribution was observed in the cemented soil shell.
• The model captures the coupled load sharing and skin friction evolution at both interfaces.

Conclusions:

• The dual-interface model provides a more accurate assessment of PCCS behavior.
• It offers theoretical support for refined design and safety evaluations of PCCS foundations.
• Understanding interface damage is crucial for optimizing PCCS performance.