Comparative Study on Performance of CFA Piles and Drilled Shafts in Dos Bocas, Mexico

This paper presents observations and findings gained from a case study which includes the design and construction of around 10,000 CFA piles and drilled shafts for a refinery project in Mexico. A dedicated pile load testing program, i.e., static and dynamic load tests, was developed and executed to check and verify the construction procedure and pile resistance and also for quality control of production piles. This study mainly compares the construction procedures and load-displacement behaviors for the two different types of non-displacement piles. Site-specific correlations between geotechnical parameters such as SPT-N versus CPT-q(c) and estimation of fines contents of soils from CPT data are also presented based on results from extensive geotechnical site characterization campaign. The observed production rate of CFA piles was about five times higher than that of drilled shafts. Static pile load test results suggest that the axial compressive pile resistance of CFA piles was approximately 10%-30% larger than that of drilled shafts, while CFA piles showed a slightly lower lateral resistance compared to drilled shafts.