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

176( ) 0. / . / 1 . / = 1005 kNR setup = R t – R EOD = 1005 – 635 = 370 kNNext, the factored pile resistance (φR) was calculated by applying φ EOD of 0.65, which wasregionally-calibrated for the State of Iowa in Chapter 6 to R EOD and by assuming φ setup of0.30 to R setup for a redundant pile group condition (β T = 2.33). Compared with the resultsestimated using the static analysis method, the number of piles required has been reducedfrom 14 to 13, at which the pile design procedure and the economic advantages ofincorporating pile setup using the proposed method in the LRFD have been demonstrated.φR == 0.65 × 635 + 0.30 × 370 = 524 kNThe revised number of piles required = 6831/524 = 13 pilesConclusionSince the number of piles has been reduced from 14 to 13 with pile setupconsideration, the efficiency of the pile foundation to support the bridge structure has beenimproved, and the economic advantages of incorporating pile setup have been demonstrated.4.12. NotationA, B = Setup factor used in Skov & Denver (1988) or Svinkin and Skov (2000)methodAR = Pile area ratioC, C h = Proposed pile setup rate or horizontal coefficient of consolidationCI, COV = Confidence interval or coefficient of variationf c , f r = Empirical consolidation factor or remolding recovery factorn, N a = Sample size or average SPT N-valueOCR = Overconsolidation ratioPI = Plasticity indexQ D , Q L = Dead load or live loadr p= Pile radius