CPT-Based Axial Capacity Design Method for Driven Piles in Clay

Abstract

There are clear advantages in the establishment of reliable, direct cone penetration test (CPT) based methods for assessment of the axial capacity of driven piles. These advantages motivated the formation of a joint industry project (JIP) under the management of the Norwegian Geotechnical Institute (NGI), which initially led to the creation of a unified database of high-quality pile load tests in sand and clay. The unified database has the consensus approval of representatives of the profession and personnel in multiple companies from the offshore energy sector. This paper presents a component of the research from the second phase of the JIP, which had the objective of developing a new CPT-based method for driven piles in clay to unify several CPT-based methods that are in use today. First, a rational basis for the CPT-based formulation is described, using trends from instrumented pile tests; the description facilitates an understanding of the approach and illustrates its empirical nature and limitations. The unified database was used to calibrate the formulation and it led to good predictions for an independent database of pile load tests and for measured distributions of shaft friction.

A Cpt-Based Multi-Spring Model for Lateral Monopile Analysis Under Sls Conditions in Sand

“…Both 𝜎 ′ 𝑟𝑐 and 𝛥𝜎 ′ 𝑟𝑑 are inversely proportional to the pile diameter, therefore the function can be extrapolated to larger pile configurations where plugging effects are less pronounced and full coring behaviour can be expected (i.e. soil within the full depth of the pile post-installation) (Lehane et al, 2020b).…”

su-Based Shaft Friction Design Method and Evaluation for Pipe Pile

“…It can be seen that the undrained strength obtained by the SHANSEP method is reliable. is paper uses an empirical method based on CPT to determine the undrained strength of clay, as shown in equation (5). Using N k � 20, the calculated undrained strength at 9.5∼10.5 m depth is 28.0 kPa, as shown in Figure 11.…”

“…e IHC S800 hydraulic hammer is used for pile Note. e tension capacity measured deducts the weight of pile and soil plug (4.550 MN); the shaft resistance in sand all uses the Unified CPT-based method [5]; the base resistance in tension is not considered. driving.…”

“…Among the API-00 [1], Fugro-05 [2], ICP-05 [3], and UWA-05 [4] methods which are applicable to sand, all but API-00 are based on CPT. Based on the four CPT-based methods, a uni ed CPT-based method has been developed by the JIP group of UWA, NGI, Imperial College, Fugro, BP, Delft university of Technology, University of Texas, DNV•GL, and Lloyd's Register EMEA [5]. e methods applicable to clay include API-00, Fugro-96 [6], NGI-05 [7], ICP-05, UWA-13 [8], and Fugro-10 [9] methods, of which API-00, Fugro-96, and NGI-05 are all based on the undrained strength of clay.…”

Assessment of time effects on capacities of large-scale piles driven in dense sands

“…The EURIPIDES joint industry project (JIP) comprised instrumented dynamic, static (tension and compression) tests on 763 mm diameter open-ended steel piles driven in dense sands at a wellcharacterised harbour site in the Netherlands (Zuidberg and Vergobbi, 1996). The high-quality static tests aided the checking and development of CPT-based pile capacity assessment methods for sands, including the ICP-05 (Jardine et al 2005), UWA-05 (Lehane et al 2005) and Unified-20 (Lehane et al 2020) approaches. However, the dynamic driving data has not yet been interpreted and integrated with the monotonic tests, including a compression re-test on an aged pile that has received relatively little prior attention.…”