Static tests on instrumented piles affected by residual load

Abstract

Abstract Analysis of results from a static loading tests on an instrumented pile usually assumes that the gage determined loads represent the true loads in the test pile. However, more often than not, residual load will have been present in the pile at the start of the static test. Disregarding these in the analysis will misrepresent the load–movement response and the loads determined from the strain–gage instrumentation, as presented in the paper. The results of three static loading tests: a 400 mm diameter, 45 m long, concrete filled, closed toe, steel pipe pile driven in soft clay, a 460 mm diameter, 22 m long bored pile (screw pile) in silt and sand and stiff clay, and a 600 mm diameter, 15 m long, jacked-in concrete pile in a residual, dense, silty sandy weathered sandstone. The measured load distributions are corrected for residual load, demonstrating the interdependence of the distributions of “False” and “True” distributions of load.