T.M. No. 15 - July 1965 



The Statistical Distribution of Ocean Wave Forces on Vertical Piling 

 by Leon E. Borgman 



Theoretical distribution and relationships concerning wave 

 forces on piling for unidirectional waves of very small amplitude 

 having narrow-band spectrum are investigated mathematically and com- 

 pared with measured data for finite waves with an almost narrow-band 

 spectrum. The usual force formula consisti-ng of a drag and an 

 inertial component, each multiplied by coefficients supposedly 

 constant, is used. A graphical method is presented for estimating 

 parameters defining these forces which permits replacing the dis- 

 tribution of the measured forces with an empirical distribution 

 function adjusted for the condit"ion that only those waves with forces 

 exceeding some significant peak value are included in the measured 

 data . 



T.M. No. 14 - October 1965 



Sand Movement Along a Portion of the Northern California Coast 

 by John Cherry 



Long-term beach and offshore sand movement along the northern 

 California coast between Drakes Bay and Russian River is studied. 

 Analysis of wave, sand, and geological data, coupled with known 

 configurations and behavioral processes of stable beaches, suggests 

 little net alongshore movement under present conditions and that 

 beaches are generally in equilibrium with negligible loss. This 

 analysis is confirmed through heavy-mineral analysis of surface 

 samples. Point Reyes and Bodega Head are indicated to be effective 

 littoral barriers to alongshore transport. 



T.M. No. 15 - October 1965 



Analysis of Wave Forces on a 50-lnch Diameter Pile Under Confused 

 Sea Conditions by B. W. Wilson 



The methods developed in the period 1955-57 for analysis of wave 

 force measurements on a 30- inch test pile in the Gulf of Mexico are 

 discussed, and procedures for reducing raw data to a form suitable 

 for digital computer operations are outlined. Measurements of ver- 

 tical reaction at the pile supports were successfully checked with 

 the record of water surface fluctuation, n (t), but calculations of 

 total force based on measured horizontal reactions could not be cor- 

 related therewith. Identification of separate wave systems suggested 

 an equivalent force, Fg (t) can be used for correlation with velocity 

 and acceleration components derived from n (t); its use is justified 

 by pilot analysis of synthetic data. By use of this analysis tech- 

 nique, it was possible to recover the values of drag and inertial 

 coefficients put i-nto the synthetic data. 



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