Title: Column Strength of Long Piles
Author(s): J. J. Hromadik
Publication: Journal Proceedings
Appears on pages(s): 757-778
Results of full-scale column tests on 80 ft long concrete piles (nominally 60 ft unsupported length), concentrically loaded, are presented. Included are 32 tests of 12 sepa-rate concrete specimens (three each of four different types); test data on three steel bearing piles are also given for comparison. The test results on the concrete specimens are compared to theoretically predicted buckling loads determined by employing Engesser’s tangent modulus in the generalized Euler equation and using test determined effective lengths. The application of the tangent modulus principles is in accordance with the works of others, who utilized Hognestad's idealized stress-strain relation for concrete. The analyses indicate that there is no evidence of a significant difference between the theoretical predictions and the test results.