Showing papers on "Groyne published in 1987"

Short-Term Impoundment of Longshore Sediment Transport.

Abstract: : The cross-shore distribution of longshore sediment transport is investigated through the distribution of sediment impounded against a shore-perpendicular barrier over short-term intervals in field and laboratory environments. For each field experiment, a low-profile groyne was deployed across a natural beach in less than 8 hr and profiles near the groyne were repeatedly surveyed for 8 to 20 hr thereafter. For each laboratory experiment, a low-profile barrier was installed across a pre-equilibrated fine sand model beach, and profile changes near the barrier were measured after 5 to 40 minutes of regular, obliquely incident, unidirectional wave action. Breaking wave angle and longshore current and wave height across the surf zone were also measured. The effects of crossshore transport and tidal fluctuation were addressed in the survey data, and the effectiveness of the barriers as impoundment agents is discussed. Local downdrift profile changes were found to be poor indicators of the local updrift impoundment. In general, the longshore transport profiles were found to be bimodal with peaks just landward of the breakpoint and near the shoreline. The relative significance of the longshore transport shifted from the near-breakpoint peak to the near-shoreline peak as the wave condition varied from spilling to collapsing breakers. Keywords: Beach erosion; Groins(Shore protection).

Evaluation of Sand Filled Geotextile Groynes Constructed on the Gold Coast, Australia

Abstract: The key aspects, features and installation of the three sand filled geotextile groynes constructed on the Gold Coast, Australia by the Gold Coast City Council are discussed. The two single tube geotextile groynes have been completely successful, while the large multitube Kirra groyne, being an ambitious prototype had problems.