CORRELATION OF CAPWAP WITH STATIC LOAD TESTS

Signal matching analysis such as CAPWAP is considered a standard procedure for the capacity evaluation from high strain dynamic pile testing data. Using one pile top measurement, like the downward stress wave, CAPWAP iteratively alters the soil model to calculate and obtain a best match with the complimentary wave, such as the measured upward traveling wave. Previous studies of databases, and individual experience, have demonstrated generally good correlation of CAPWAP signal matching results on dynamic restrike tests with static load tests. The Proceedings of all six previous Stresswave conferences were reviewed to extract correlation cases which included both CAPWAP restrike results and static load tests. Results are summarized in a database and also presented separately for both 119 driven piles and for 23 cast-in-situ foundations such as drilled shafts and augercast-CFA piles. A statistical evaluation of results categorized by pile type is presented with a discussion of noted differences. Combined with previous studies in 1980 and 1996, the database now contains 303 case histories. The statistical results are valuable for future research into the reliability evaluation of safety and resistance factors of dynamic methods.