Introduction
In this tool (breakwater design) you can compute required dimensions, overtopping, cross-sections and costs of breakwaters.
The tool requires at least a breakwater and bathymetry data (you can inspect the generic data availability in the top panel of the tool).
Optionally, any generic wave data can also be used, in order to fill the wave condition fields.
Computations of breakwater dimensions and costs are based on rough guidelines in the rock manual.
Results of the breakwater tool should therefore be interpreted with a considerable range of uncertainty.
How to use the tool
- Open a new project
- Start in Generic Data by defining a
User input fields
A number of user input fields are provided which can be used to adjust the calculation according to the local situation. Default values are provided for each input field. The following inputs are defined:
Generic computation settings
| Default Value | Unit | Min. | Max. | Brief Description | |
|---|---|---|---|---|---|
| Structure | Select one of the breakwater structures that you want to design. | ||||
| Safety level | Select the design safety level. | ||||
| Allowable overtopping | 0.03 | l/s/m | 0.03 | 50 | Based on the selected safety level, this shows the allowable overtopping for the breakwater design. |
| Depth type | Toggle between Varying and Uniform. In case of a Varying depth type, the bottom depth provided by Generic Data will be used. | ||||
| Uniform depth | 10 | m | 0.01 | 9999 | In case a uniform depth type is selected, provide the depth value. |
| Automated crestheight calculation | True | In case this is selected, the crest height will be automatically calculated based on the design criteria. In case this is not selected, provide a crest height. | |||
| Slope | 3 | - | 0.25 | 100 | Provide the outer slope of the breakwater (as 1: .., e.g. 1:3). The inner and outer slope are considered the same. |
| Crest width | 5 | m | 0.01 | 999 | Provide the width of the top of the breakwater (crest). |
| Crest height | 0 | m MSL | 0.01 | 999 | In case the automated crest height calculation is switched of, provide the crest height of the breakwater. |
Design storm conditions
| Default Value | Unit | Min. | Max. | Brief Description | |
|---|---|---|---|---|---|
| Location | Offshore | Offshore | Nearshore | Indicate whether the design storm conditions are provided at an offshore or nearshore (at the breakwater toe). Using lineair wave transformation the wave height is transformed to nearshore conditions in case of offshore storm conditions. | |
| Hs | 3 | m | 0.01 | 20 | Significant wave height during the design storm condition. |
| Tp | 12 | s | 0.01 | 20 | Wave peak period during the design storm condition. |
| Water level | 1 | m, MSL | -10 | 10 | Provide the water level at the tip of the breakwater w.r.t. to MSL that is present during storm conditions. |
| Storm duration | 6 | hr | 0.1 | 48 | Total duration of the storm. This is used to calculate the total number of waves that is expected to reach the breakwater. |
| Breaker parameter | 0.73 | - | 0.0001 | 1 | Defines the wave height at which waves start to break. The maximum wave height is defined by the breaker index times the local waterdepth. |
| Offshore depth | 100 | m | 0 | 9999 | In case the design storm conditions are provided at an offshore location, provide the offshore depth of that location. Using lineair wave transformation the wave height is transformed to nearshore conditions. |
Armouring
Reduction factors
Unit cost price
Tool limitations
The following processes are not included in the tool: waves approaching under an angle, bed level changes caused by wave reflection, shoals causing wave breaking etc. Besides, the tool only provides linear cross-sections comprising of 3 default materials, without providing information on the breakwater toe or round heads. Results of the breakwater tool should therefore be interpreted with a considerable range of uncertainty.
Example cases
The following files (.dsproject) can be downloaded and loaded into CoDeS to serve as examples. They are not based on actual projects, but are intended as illustration.
Unzip the files to an convient folder (but make sure the file structure does not change), and open the .dsproject file from within CoDeS.
