Abstract:
Deep foundation lateral load tests ideally should include the use of inclinometers or similar instruments to generate a displacement vs. depth profile. If inclinometers are not available, strain gages installed in the test element (driven pile, drilled shaft, augercast pile or similar) may be utilized to estimate the displacement, provided they are embedded in the element above the point of lateral fixity with opposed pairs of gages oriented properly in the direction of loading. A simple technique for numerically integrating strain gage data to obtain the lateral displacement profile is developed and discussed. The results of this technique are validated by comparing its output to a more sophisticated data curve-fitting method as well as available Shape Array Accelerometer (SAA)-type inclinometer data in several full-scale lateral load tests. Based on this validation, the technique is improved by including the lateral head displacement (measured separately using displacement transducers) as a boundary condition. The improved method is then employed to analyze test data sets where no other instrumentation is available.