DOI

10.5703/1288284313263

Abstract

This research focused on the drivability and load-carrying capacity of both open and closed-ended steel pipe piles. Two pipe piles (one open-ended, the other closed-ended) were installed in a sandy soil to the same depth. The site was extensively characterized. SPT and CPT tests were performed both before and after pile installation. A variety of soil indices and shear strength parameters (such as the constant-volume friction angle) were measured in the laboratory. The piles were fully instrumented, permitting separate measurement of shaft and base capacity for the closed-ended pile and shaft, annulus and soil plug capacities for the open-ended pile. The results are presented in a variety of ways. In particular, values of pile resistance are presented normalized with respect to CPT cone resistance values both along the shaft and base of the piles for quick reference. The test results for the openended piles are quite unique. Two design methods are proposed for open-ended piles based on the field load test as well as on results found in the literature. In one method, pile resistances are referred to either the soil plug length or incremental filling ratio. In the other method, pile resistances are correlated to the CPT cone resistance. Comparisons of the proposed methods with the load test results and with methods currently in use are quite favorable. The present research suggests current pile design methods may be excessively conservative. It seems that cost savings from similar research, where complete measurement of all variables of interest both for the piles and for the soil deposit where the piles are installed are done, can be very substantial if the methods proposed here are validated further. It appears that such savings would be in the interest of DOT's and the FHWA.

Report Number

FHWA/IN/JTRP-2002/04

Keywords

piles, piling, pipe piles, open-ended pipe piles, closed-ended pipe piles, cone penetration test, CPT, cone resistance, bearing capacity, sand, SPR-2361

SPR Number

2361

Project Number

C-36-45R

File Number

6-18-16

Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, IN

Date of this Version

2002