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199Table 5.2: Comparison of Resistance Factors Obtained using the Conventional LRFDframework based on WEAP-SACaseResistanceRatio (RR)SampleSizeλ RCOV RNominal PileResistance(R)β T = 2.33 β T = 3.00φ φ/λ φ φ/λ1 R m-t /R e-restrike 7 0.959 0.140 R e-restrike 0.69 0.72 0.58 0.612 R m-t /R e-EOD 30 1.723 0.211 R e-EOD 1.11 0.65 0.91 0.533 R m-t /R e-t30 1.029 0.190 R e-t (Eq. 5.1) 0.69 0.67 0.57 0.55(28) (1.059) (0.156)4 R m-EOD /R e-EOD 8 1.111 0.157 R e-EOD 0.78 0.71 0.65 0.595 R m-setup /R e-setup 28 0.950 0.317 Not applicable for Eq. (5.2)The target reliability indices (β T ) of 2.33 (corresponding to 1% probability of failure) and3.00 (corresponding to 0.1% probability of failure) as recommended by Paikowsky et al.(2004) for representing redundant and non-redundant pile groups, respectively, were used inthe calculations.Based on the calculated resistance biases and coefficients of variation, the respectiveresistance factors (φ) and efficiency factors (φ/λ) were calculated using Eq. (5.2) as listed inTable 5.2. Due to the occurrence of pile setup in each data point that was measured using aSLT conducted several days (ranging between 1 and 44 days) after EOD, a large λ R value of1.723 and a moderate COV R of 0.211 were determined for Case 2 (R m-t /R e-EOD ), andunrealistic high resistance factors of 1.11 and 0.91 were yielded for the β T values of 2.33 and3.00, respectively. It should be recognized that a constant ―pseudo pile setup factor‖ resultedfrom a relative large λ R value during the resistance factor calibration using Eq. (5.2),regardless of cohesive soil properties and time elapsed, was indirectly included in theresistance factors. Although the total pile resistances were effectively estimated using Eq.(5.1a), as shown in Case 3 with the λ R value (1.029) closes to unity and a moderate COV R of0.190, the difference between the COV R value of 0.190 for Case 3 and 0.317 for setup (Case5) confirms that the conventional LRFD calibrating procedure cannot account for thedifference uncertainties associated with the initial pile resistance (R EOD ) and the setupresistance (R setup ) within the conventional LRFD frame work. Even if the same sample sizeof 28 for setup is evaluated for Case 3, the COV R value reduces to 0.156, which is againdifferent from that for setup. Therefore, use of a single resistance factor of 0.69 when β T of