REGION SPECIFIC CALIBRATION OF GEOTECHNICAL RESISTANCE FACTORS FOR AXIALLY LOADED DRIVEN STEEL PILES USING DYNAMIC MONITORING RESULTS

ABSTRACT: Driven steel piles are the most common type of deep foundation used in Canada to support many structural elements of the oil and gas, and infrastructure projects. To calculate the capacity of a pile during preliminary design, semi-empirical equations are generally used. Although these equations are commonly used in practice, there are always uncertainties in calculating the geotechnical pile capacity, due to the uncertainty of the soil parameters (obtained from site characterization) and construction quality. To account for these uncertainties and ensure the foundation safety under working loads, a Geotechnical Resistance Factors (GRFs), recommended by the Canadian Foundation Engineering Manual (CFEM), is applied to the calculated pile capacity. To maximize this factor for driven piles within a specified region, it is required to calibrate pile capacity with respect to the region’s soil conditions. This study aims to improve the recommended GRF value incorporated with Pile Driving Analyser (PDA) testing using probabilistic procedure thereby, increasing factored pile capacity and reducing costs. A case study at Winnipeg region is used in this research to demonstrate the methodology. The GRF value for axial capacity is calibrated using a Monte Carlo Simulation, site-specific geotechnical data, and PDA test results. Cost-Benefit Analysis is then carried out using the calibrated GRF values to obtain an accurate cost reduction estimate.