Effect of wall thickness on plugging of open ended steel pipe piles in sand

This paper presents the results of a pile installation and testing program for instrumented 30-in long, 3.5 in diameter steel pipe piles with wall thicknesses 0.120 in, 0.216 in, and 0.290 in, installed by jacking into Oklahoma Sand specimens created by pluviation in a CPT calibration chamber at the University of Texas. Continuous measurements of pile penetration, plug height and pile resistance were obtained as the piles were pushed into the sand specimens with the calibration chamber pressurized at 10 psi. The instrumentation involved a load cell, a position transducer, and an LVDT. For comparison purposes, an additional test was performed on a 3.5 in diameter closed end pile. This paper presents a description of the model pile installation facility, the instrumented piles, the model sand, the testing program, and, the test results obtained. The results of the testing program indicate that piles with thicker walls require less penetration to develop plugging. Pile capacities were also predicted using the conventional procedures and found to under-predict measured values. The differences are attributed to development of higher side friction caused by plugging. Copyright ASCE 2007.