Combination of O-cell test and conventional head-down test

10.1061/41093(372)8Geotechnical Special Publication198 GSP240-259GSPU

Failure of a barrette as revealed in an O-cell test

10.1061/9780784412084.0023Geotechnical Special Publication227 GSP307-321GSPU

Load transfer curves from a large-diameter pipe pile in silty soil

This paper presents load transfer curves interpreted from a static load test performed on a large-diameter pipe pile in silty soils. In large-diameter driven piles and drilled shafts, appreciable movement is needed to mobilize toe resistance and thus settlement may control the design. Advanced load transfer methods require the prediction of the load transfer behavior along the shaft (i.e. t-z curve) and beneath the toe (i.e. q-z curve) of the pile. A number of generic load transfer curves for sand and clay are reported in the literature but limited information is available for large diameter piles and intermediate soils such as silt. This study develops t-z and q-z curves for silty soils from the analysis of a static loading test performed on an 1.8-meter diameter pipe pile in Rhode Island. The t-z curves from the test pile showed a softer load-movement response in comparison to those from slender piles in the literature. The results suggest that use of existing empirical t-z curves developed from slender piles in sands could lead to inaccurate load transfer analyses in large-diameter piles in silty soils. © 2012 American Society of Civil Engineers