This concept utilizes several narrow graded classes

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: class berm breakwater was developed in Iceland, and has been widely used there over the past 20 years. This concept utilizes several narrow graded classes of armour stone, with the largest stone placed in the critical (most exposed) areas of the cross-section, thereby providing a lower value of Hs/∆Dn50 and increased stability, with the potential for more efficient use of the quarry. This concept has been recently applied to two breakwaters in Norway with design wave heights in the order of Hs = 7.5 m (refer to Sigurdarson et al, 2005). An evaluation of the two-berm breakwater concepts was undertaken. The multi-class concept was identified as the preferred design concept, due to the fact that it was anticipated that this approach would achieve the required performance objectives (i.e. resist the extreme design event without significant stone motion or profile development) with a smaller volume of stone, without a significant increase in unit costs. Preliminary design development was undertaken based on published design guidance (such as PIANC, 2003), assuming three classes of armour stone (2-6 t, 6-12 t and 12-18 t). In addition, the design cross-section incorporated an interim armour layer to provide temporary protection against the persistent swell conditions and to meet the fast track project schedule (dredging and quay construction require the protection of the breakwater). The preliminary design cross-section is illustrated in Figure 7 (the dark area is the interim armour layer). Figure 7 – Preliminary Design Cross-Section for Breakwater 9 PHYSICAL MODELING AND FINAL DESIGN OF BERM BREAKWATER Two separate three-dimensional physical model investigation were undertaken to support final design development for the port and breakwater. Wave agitation and ship response tests were undertaken at a scale of 1:70 in a 20 x 30 m wave basin at the Canadian Hydraulics Centre. These tests were used to develop an estimate of downtime at the primary berth, and to refine the overall layout of the port (navigation simulations were also undertaken to support this process. The br...
View Full Document

Ask a homework question - tutors are online