Toward a generalized guideline to inform optimal site investigations for pile design

Abstract

Insufficient or inappropriate soil testing can lead to a range of undesirable consequences, and yet there is no guideline for optimal investigation. This study analyses the influence of test type, number of boreholes, data interpretation, soil conditions, and structural configuration on site investigation performance. In addition to providing general recommendations, the relative sensitivity of these variables on performance is determined. Performance is assessed in terms of total expected project cost while implicitly incorporating the risk of damage from poor investigation. The framework for this study involves the use of randomly generated, variable, single layer virtual soils in a Monte Carlo analysis. It was found that optimal investigations can produce net savings in the order of several hundreds of thousands of Australian dollars, and key features of a future site investigation guideline are identified.