PENCEL Pressuremeter Test Evaluation for Developing P-Y Curves for Driven Piles

The study goal was to demonstrate that PENCEL pressuremeter (PPMT) test would generate reliable engineering parameter to allow engineers to more precisely carry out the standardized tests, and to produce the p-y curves for analysis and design of laterally loaded piles. The PENCEL was pushed to the desired test depth using the Cone Penetrometer equipment. Based on the results of a comprehensive testing program the evaluation indicates the testing procedure is acceptable. A recommended interpretation and procedure are presented. An evaluation of the proposed methods is presented using data from a number of in-situ PPMT tests conducted in Cape Canaveral site. From PPMT data, which were reduced to graphs of pressure versus volume and pressure versus relative change in probe radius, soil parameters including the lift-off pressure, the initial elastic moduli, the reload moduli, and the limit pressure of the soils were determined. The two latter parameters were utilized to establish the p-y curves via the conversion of the PPMT stress to force per unit length and the PPMT strain to obtain displacement. The PPMT soil parameters show good agreement with published values. Dilatometer (DMT) tests were conducted for comparisons with PPMT data. Correlations were developed between the PPMT and DMT results, which show consistency in soil parameters values. Comparison between PPMT and DMT p-y curves were performed based on the slope of the initial portion of the curve, the curves shape, and the ultimate soil resistance. The initial slope shows a good agreement for this comparison. The expected PPMT and DMT deflections within the elastic range are identical, while the expected DMT and PPMT ultimate loads are not similar. It is possible to install the PPMT in a manner which models the disturbance caused during pile installation and predict the analysis of the laterally loaded soil resistance.