Dikkowita BreakwaterDikkowita Breakwater• A new Fishing Harbour is being built 10 kilometer north of Colombo, Sri Lanka

•The harbour is protected by two breakwaters and is designed for 125 ft. fishing vessels.

•Both breakwaters have a concrete crown wall

•The total length of the breakwaters is more than 1 kilometer.

BreakwaterA structure protecting a shore area, harbor, anchorage, or basin from gigantic waves

Elements of a Breakwater & FunctionsFoundation – Provides embankment stability

Core – Provides Bulk of structure and reduces wave transmission

Under layer – Contains the core and provides foundation for armor

Armor layer – Provides wave protection

Crest – Provides access and reduces overtopping

Toe – Support the main armor and prevents foundation erosion

Concrete Armor units for Dikkowita breakwatersXblocs® (trade name) six-legged mass concrete structure used as armor unit

Innovative combination of hexapod and accropod

Applied for offshore breakwaters

Automatically interlocking single layer armor unit

Highly porous armor layer absorbs energy of upcoming waves and dissipate

Highly porous armor layer minimizes wave overtopping and reflection

Economical compared to other concrete armor units

Different types of armor units

Cost of different types of armor units

Why use Xbloc Concrete Armor units?•Economical - achieve good interlocking, placement of the units is straightforward, reducing both construction time and overall costs.

•Reliable - Extensive research both on hydraulic stability and structural integrity has proven •Outstanding structural integrity

•Easier fabrication - have a simple and mostly rectangular shape•Faster placement- designed for ‘automatic interlocking’ and thus can easily find a stable position on the slope•Lower concrete volume - provide large hydraulic stability and require relatively low packing densities

•Easy to use - Easy to produce, Easy to store, Easy to place•Ecological - create an artificial reef, high porosity provides a healthy environment for reef vegetation thus biodiversity will be enhanced

Construction of Dikkowita Breakwater Armor Layer

Casting Xbloc concrete armor units

At Completion

Why Toe Protection ?•Support the armor layer from wash out

•Prevent foundation exposure and submerging of structure

Without toeWith toe

Toe protection used at Dikkowita Breakwater•Has used new concept of toe with Xbase (trade name)

•Similar material to Xbloc and similar properties•Advantages of special toe unit

-High hydraulic resistance -Low centre of gravity -Easy casting

•Advantages compared to conventional rock toe-Higher stability -Lower use of material -Easier and faster to construct -Can be used as crest units

Lab testing for Toe units

Placing of Xbase Toe units