Caisson Design by Instrumented Load Test

Three instrumented axial load tests were performed on 42 inch diameter caissons (drilled piers). These caissons were installed in marine sediments of dense sand overlain by soft sand-clay mixtures. Correlations were made with the Standard Penetration Test to develop design relationships. Production caissons were then designed based on these relationships. Test caissons were approximately 54 feet long and installed by the slurry displacement method. Test loads were carried to 1,000 tons. Mustran cells were used to determine loads in the caissons at different depths. Resulting data is presented graphically as load versus settlement, load versus depth (load distribution), and side friction and end bearing versus both applied load and displacement (load transfer). Special construction considerations and caisson integrity as observed after excavation are presented