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

8Board (IHRB) sponsored research project to develop LRFD bridge foundation designrecommendations for the State of Iowa. One of the research objectives is to developregionally calibrated LRFD resistance factors for dynamic analysis methods. The researchfocuses primarily on the most commonly used steel H-pile foundations in Iowa. In lieu withthe problems encountered at the national and the state levels, technical problems listed belowwere examined in order to establish cost-efficient LRFD pile design guidelines at the statelevel.1. Pile setup has not been successfully estimated and implemented in current piledesigns;2. Pile setup quantification methods have not been incorporated in current AASHTO(2007) LRFD Specifications;3. Construction control has not been considered in pile designs prior to pile driving; and4. Current recommended dynamic soil parameters are vague and have not beensuccessfully correlated with any measurable soil properties.1.4. Research Scope And ObjectivesIn light of the aforementioned challenges and opportunities, this research is on thecharacterization of soil-pile responses under pile driving impact loads and how thisinformation could be used to improve design and construction control of piles subjected tovertical loads in accordance with LRFD. The scope of the proposed research was achievedthrough the following objectives:1. Improve dynamic pile driving characterization of vertically loaded piles;2. Investigate variation of pile resistance as a function of time and soil conditions;3. Incorporate the advantages of pile setup into the LRFD;4. Recommend regional LRFD design guidelines for dynamic analysis methods; and5. Improve the estimation and verification of pile performances in terms of strengthusing dynamic analysis methods.