Funded by the California Department of Transportation. Investigators – Y. H. Chai and T. C. Hutchinson.
Abstract: The objective of the project is to characterize the in-ground plastic hinging of reinforced concrete piles under the interaction of a cohesionless soil. Standard Caltrans 406 mm diameter CIDH reinforced concrete piles were embedded in a large-diameter soil container and subjected to a combined axial compression and quasi-static reversed cyclic lateral loading. The influence of soil density on the ductility capacity, plastic hinge length and depth to plastic hinge were studied. In addition, the kinematic relation between the global ductility demand and local ductility demand was being investigated using the nonlinear moment-curvature response of the concrete pile and nonlinear Winkler soil springs.
Key Statistics – Soil Container 6.7 m in diameter and 5.5 m depth. For 406 mm diameter test pile, longitudinal reinforcement content = 2.1% and confining steel ratios = 0.57 and 1.07%. Test soil was a screened river sand with a medium grain size of 0.5 to 0.6 mm diameter. For the dense sand conditions, CPT tip resistance = 14.5 MPa, and for the loose sand condition, tip resistance = 3.5 MPa.
For photos of test setup and pile damage, click here.
Key Publications:
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Y. H. Chai and Tara C. Hutchinson (2002), “Flexural Strength and Ductility of Extended Pile-Shafts – Experimental Study”, Journal of Structural Engineering, ASCE, Vol. 128, No. 5, pp. 595-602.
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Y. H. Chai (2002), “Flexural Strength and Ductility of Extended Pile-Shafts – Analytical Model”, Journal of Structural Engineering, ASCE, Vol. 128, No. 5, pp. 586-594.
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S. T. Song, Y. H. Chai and T. H. Hale (2005), “Analytical Model for Ductility Assessment of Fixed-Head Concrete Piles”, Journal of Structural Engineering, ASCE, Vol. 131, No. 7, pp. 1051-1059.