Laserfiche WebLink
22 I Port of Everett—South Terminal Wharf& Electrical Upgrades—Phase 2 <br /> Where: <br /> s, _ aE,L` 1/2 <br /> 2AE 1 <br /> And, <br /> Q=Nominal pile capacity in pounds, <br /> Er=Rated hammer energy in foot-pounds, <br /> L=Length of pile in feet, <br /> A=Cross-sectional area of pile in square inches, <br /> a=Hammer efficiency= Ratio of the delivered energy to rated energy(typically about 0.8), <br /> E=Modulus of elasticity of pile material in psi, and <br /> S=Final set, penetration per blow in feet. <br /> Both theoretical considerations and pile installation experience indicate that the pile capacity estimated <br /> from resistance to driving is typically less than the long term static pile capacity. Because of this effect, pile <br /> resistance derived from criteria based on initial driving is considered to underestimate the long-term <br /> capacity of the driven piles. <br /> Pile Installation and Construction Considerations <br /> This section of the report contains installation and construction considerations related to pile driving. <br /> General Considerations <br /> We recommend the following for general pile installation and construction: <br /> • Pile spacing within groups of driven piles or adjacent to existing piles should be no less than three pile <br /> diameters on center. <br /> • Existing riprap on the slope will need to be removed locally for setting the steel pipe piles,and then <br /> replaced after pile installation. <br /> • An air bubble curtain,or similar,will likely be required by the permitting agency while impact driving <br /> the steel piles in the water. <br /> • All piles should be driven to the minimum embedment into the bearing stratum. <br /> • Permitting considerations often require minimizing the duration of impact driving,and control the <br /> total number of impact driving blows. It may be necessary to install the pile with a heavy vibratory <br /> hammer to meet such impact driving restrictions.When a vibratory hammer is used,capacity should <br /> be verified by restriking with an appropriately-sized impact hammer. <br /> It is important to embed the piles firmly into the bearing layer below any soft layers to minimize the <br /> potential for pile settlement. <br /> 19232-01 <br /> Y <br /> December 6,2017 HMTC ROWS[R <br />