Field measurements of wave pressure distribution near a pair of piles

This paper details on the field measurements conducted on neighbouring piles to study the pressure variations. It has been established that for a pair of sheltered piles the direction of wave approach influences the drag and inertia coefficients apart from other routine functions like Reynolds number, Keulegan Carpenter number, frequency parameter etc. Though the present laboratory based data on drag and inertia coefficients compare well with the other wave tank experiments reported in the literature, the field results consistently contradict the lab data emphasizing the need for many more field measurements. For sheltered piles, the highlight of the results is that the Cd and Cm can go upto 9.0 for large diameter piles and 6.0 for small diameter piles even if s/D is greater than 4 which the laboratory studies fail to predict. The present exercise therefore recommends the use field based coefficients rather than lab based values for the design purposes.