S - Kam Ng PhD Dissertation Final.pdf - Digital Repository of CCEE ...

172welcoming, and closed-form method, which follows the expanded LRFD framework (Eq.(4.11)), to compute the resistance factor will be beneficial in the future for integrating theproposed pile setup method into the LRFD.4.9. ConclusionsAlthough pile setup depends of the properties of surrounding soil, the existing pile setupestimation methods available in the literature rarely use any soil properties and usuallyrequire inconvenient pile restrikes in estimating pile setup. These limitations and thesuccessful correlation between pile setup and soil parameters described in the companionpaper (Ng et al. 2011b) motivate the development of a new pile setup method. From theanalyses of the pile and soil test data, the following conclusions were drawn:1. The proposed pile setup equation incorporates the commonly used SPT N-valueand the horizontal coefficient of consolidation (C h ) to representing thesurrounding soils and employ an equivalent pile radius to representing the pilegeometry. The proposed method also utilizes the initial pile resistance estimatedat the EOD using either CAPWAP or WEAP-SA, which eliminates the need forperforming any inconvenient restrikes. The proposed method accounts for theactual time immediately after a pile installation and uses a reference time at theEOD (t EOD ) to be as small as 1 minute to quantify the pile setup occurring afterthe EOD.2. The proposed setup method was validated using additional twelve steel H-piledata records from Iowa and five other well-documented tests found in theliterature with different H-pile sizes. It has been shown that the proposed methodadequately and confidently estimates the setup for steel H-piles, so that thedifference between measured and predicted pile resistances falls within 8% and11% for 90% and 98% confidence intervals, respectively.3. The proposed method was also validated using six cases available in the literaturefor large displacement piles with different types and sizes providing satisfactorypile setup estimations with better prediction for small diameter piles (pile