Research and Development Studies for ELCOMAX® ELCOROCK® Geotextile Sand Containers
Client: ELCO Solutions Australia Pty Ltd
Project Reference: 05050
WRL Technical Reports: Field Measurement of ELCOMAX® ELCOROCK® Geocontainers at Clifton Springs Boat Harbour, Victoria (2008/06); Research and Development Studies for ELCOMAX® ELCOROCK® Geotextile Sand Containers (2008/05)
ELCO Solutions Australia (www.elcorock.com) commissioned WRL to undertake a research and development (R & D) program for ELCOMAX® ELCOROCK® geocontainers. ELCOROCK® geocontainers are a product marketed by ELCO Solutions Pty Ltd, for use in a variety of applications including coastal protection and armouring. The R & D program conducted by WRL investigated the physical properties and in situ characteristics of the ELCOROCK® geocontainers when used for coastal applications.
It was conducted as a two part study:
- The initial part consisted of field measurements of prototype ELCOMAX® ELCOROCK® geocontainers as they were being used in a coastal installation
- The second part consisted of scale model laboratory tests
Phase 1 of the research program involved taking situ prototype geocontainer measurements at Clifton Springs boat harbour, approximately 15 km east of the city of Geelong, Victoria. The installation was being constructed by contractors on behalf of the City of Greater Geelong. The field measurements were undertaken as a cooperative effort between WRL, ELCO Solutions, and on site construction staff. WRL measured a range of properties for six nominally 0.75 m3 geocontainers and five nominally 2.5 m3 geocontainers, with the aim of gathering relevant information for hydraulic design and scale modelling. Both dry fill and hydraulically assisted fill techniques were used for the measured bags, with geocontainers made of both vandal-proof and non-vandal-proof materials being tested.
Phase 2 of the research program involved detailed hydraulic modelling of various revetment structures having model parameters consistent with the field measurements from Phase 1. Scale laboratory tests were conducted in the 3 m wave flume at WRL at a scale of 1:10. A revetment constructed from these units would typically be built at the back of the beach against an existing dune, for protection of landward coastal assets. As the study was not site specific, generic water level and design wave combinations were investigated to cover a range of conditions likely to be encountered. Various combinations of wave height, wave period (both monochromatic and irregular) and water level conditions were tested against combinations of three revetment structure slopes and three foreshore slopes.
The investigation yielded several important conclusions. As expected, the geocontainer stability was found to decrease with increasing wave height and period; however, increasing revetment slope steepness provided increased stability. Design guidelines to be used by coastal engineers when planning a revetment or seawall to be constructed from ELCO Solutions’ geocontainers were generated for various real world conditions.
Further preliminary tests of the ELCOMAX® ELCOROCK® geocontainers in groyne arrangements were also conducted.
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