Assessment of Direct Cone Penetration Test Methods for Predicting the Ultimate Capacity of Friction Driven Piles

2004 ◽  
Vol 130 (9) ◽  
pp. 935-944 ◽  
Author(s):  
Murad Y. Abu-Farsakh ◽  
Hani H. Titi
Keyword(s):  
Cone Penetration Test ◽  
Test Methods ◽  
Ultimate Capacity ◽  
Penetration Test ◽  
Driven Piles ◽  
Cone Penetration

The Use of a Stress Rheometer in Lieu of Cone Penetration

2005 ◽  
Author(s):  
Bryan Johnson
Keyword(s):  
Cone Penetration Test ◽  
Test Methods ◽  
Penetration Test ◽  
Cone Penetration ◽  
Numbering System ◽  
Non Linear ◽  
Grease Manufacture ◽  
Reporting Method ◽  
Service Field ◽  
Linear Nature

The Cone penetration test is used to provide a measurement of grease stiffness and is considered the most important of laboratory performed grease tests. The design of this test was intended to support new grease manufacture and sales. This test is not well suited for used grease as it requires a volume of grease which in most cases exceeds the volume of sample obtained from an in service field machine. The reporting method for cone penetration is very crude. The results are misleading in that the NLGI numbering system appears to be linear (0, 1, 2, 3 etc.) but the grease consistency changes are not linear. For example, one would reasonably think that NLGI 4 grease would be twice as stiff as an NLGI 2 and 4 times as stiff as an NLGI 1. Rheometer data is reported in Pa and these units avoid the awkwardness of the NLGI scale. When comparing this data to cone penetration, the non linear nature of the NLGI scale becomes apparent. A Good correlation was obtained between the test methods and it is concluded that use of a rheometer in lieu of cone penetration is both desirable and acceptable when monitoring the consistency of new grease or in service greases.

Cone penetration test (CPT) methods for end-bearing assessment of open- and closed-ended driven piles in siliceous sand

2008 ◽  
Vol 45 (8) ◽  
pp. 1130-1141 ◽  
Author(s):  
Xiangtao Xu ◽  
James A. Schneider ◽  
Barry M. Lehane
Keyword(s):  
Small Diameter ◽  
Predictive Performance ◽  
Cone Penetration Test ◽  
Offshore Structures ◽  
Penetration Test ◽  
Driven Piles ◽  
Cone Penetration ◽  
Pile Installation ◽  
Diameter Pipe ◽  
Load Tests

The cone penetration test (CPT) has been used as a means of assessing the end bearing of driven piles in sand for many decades. This paper examines the predictive performance of four new such CPT-based methods recently included in the commentary of the 22nd edition of the American Petroleum Institute’s recommended practice for fixed offshore structures. It is demonstrated that the formulations given by one of these methods, referred to as UWA-05, provides better predictions than the three other CPT methods when tested against (i) an existing database of base-capacity measurements, (ii) results from a new series of load tests on small-diameter piles, and (iii) base capacities measured in two recently conducted load tests on 1.5 m diameter pipe piles. It is shown that the UWA-05 has better predictive performance (and hence reliability) as it accounts explicitly for the effects of partial plugging during pipe–pile installation and for variations in CPT resistance in the vicinity of the pile tip.

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