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

362.3.9. Example calculationReferred to the PDA record shown in Figure 2.2, the measured forces and velocitiesat time of initial impact (T1) and at time of reflection of initial impact from pile toe (T2) aftera duration of 2L/C as well as the steel H-pile properties are listed as below:1. FT1 = 410 kips;2. FT2 = -20 kips;3. VT1 = 12.4 ft/s;4. VT2 = 9.5 ft/s;5. E = 30,000 ksi;6. A = 16.8 in 2 ; and7. C = 16,807.9 ft/s.Using these numerical values, the total static and dynamic soil resistance on the pile (RTL)was calculated using Eq. (2.5) as follows, - , -, - , -The maximum static resistance (RMX) was found to occur at a time of 7.4 ms after the timeof initial impact (T1). Thus, referred to the PDA record shown in Figure 2.2, the force andvelocity at the time when RMX occurred (t m ) were 115 kips and 2.5 ft/s, respectively. Theforce and velocity after the time (t m ) for a duration of 2L/C were 107.9 kips and -0.7 ft/s,respectively. Using Eq. (2.9) and assuming a case damping factor (J c ) of 0.7 for a typicalcohesive soil in Iowa, the calculation of the RMX was shown as below. In addition, thepercent shaft resistance and end bearing are estimated using the PDA, and the procedure wasillustrated in Ng et al. (2011).( ) {( ) [ ( ) ( )] ( ) [ ( ) ( )]}*( ), - ( ), -+