CMS-Flow Rubble Mound Structures
Introduction
Rubble mounds are commonly utilized in the construction of breakwaters, jetties, revetments, and groins. These structures play an essential role in harbor protection, channel navigation, shoreline defense, and in managing flow, sediment movement, and wave energy mitigation. Figure 1 illustrates the implementation of a rubble mound breakwater. Given their significant impact on hydrodynamic behavior and sediment dynamics in coastal areas, it is critical for the CMS to accurately simulate the influence of rubble mound structures.
Usage of Rubble Mounds for CMS in the SMS
Early SMS versions (< 13.0)
Previous documentation (Link given below) described the formulation and implementation of Rubble Mound structures in CMS, detailing input requirements for SMS versions up to 11.2. This implementation required hand-manipulation of the CMS-Flow parameter files to add in lists of cells and option values.
A technical note was started in 2024 for the newer implementation of Rubble Mounds. With the implementation of the other structures being imminent in SMS 13.4, the material for Rubble Mounds will be incorporated into a larger Special Report in FY25 that covers all four structures. The original method for implementing Rubble Mounds in CMS is covered by the technical note listed below.
Later SMS versions (13.0 to 13.3.8)
An undocumented update in SMS version 13.0 introduced a method to use constant values for cells enclosed within a polygon. There was no implementation of datasets to hold the parameter values in this version, however. This implementation created a "Rubble Mound Jetties" coverage that the user must populate and attach to the CMS-Flow simulations.
Recent SMS version (13.3.9+)
The rubble mound polygon dialog in SMS 13.3.9 and later was modified to allow for user-selection of either constant values or datasets for rock diameter, base depth, and porosity.
Future SMS versions (13.4.x)
- The existing "Rubble Mound Jetties" coverage beneath the CMS-Flow model option in SMS 13.3 and earlier has been renamed "Rubble Mound (legacy)" in the new interface.
- A new "Structures" coverage has been added beneath the CMS-Flow model option in SMS 13.4 and later. This one coverage will handle Rubble Mound structures as well as three new types: Culverts, Weirs, and Tide Gates.
- In the new coverage, Rubble Mound structures will continue to be defined with polygons where each can have a set of attributes (either constant or from a dataset).
- The "Structures" coverage will need to be applied to the CMS Simulation in order to export the appropriate cards to the parameter file.
Values needed by the CMS for each Rubble Mound polygon are listed in the table below. If there is a user-definable option in the dialog for the user to enter a value, the word 'Dialog' is shown in column 3, otherwise the words 'No dialog' are written in column 2.
| Cell IDs | No dialog |
| Name | Dialog |
| Rock Diameter | Dialog |
| Porosity | Dialog |
| Base Depth | Dialog |
| Computation method | Dialog |
SMS will handle the assignment of the appropriate values for Cell IDs.
CMS-Flow specific information for SMS 13.4+
The parameters/selections for each Rubble Mound structure polygon will be exported to the ‘.cmcards’ file in the form of a block of values. This implementation has been confirmed to work with CMS 5.3.12 and later.
- Before each rubble mound structure is exported to the .cmcards file, one line defining the ID dataset is written. These IDs contain a zero for cells not associated with a rubble mound, otherwise an integer (i.e., 1, 2, or 3) which defines the order of the rubble mound blocks written in the parameter file.
- The Rubble Mound parameter cards needed for each structure are added to a block with a corresponding BEGIN/END statement for each rubble mound are listed in the table below.
- Constant cards take one parameter, Dataset cards take two. This is defined in column 3.
- For readability and to be consistent with other cards in the .cmcards file, all values should start in column 36 and 3 spaces written between each value per line if more than one.
| Cardname | Indent 2
spaces? |
Number
of vals |
Type of value
written |
|---|---|---|---|
| RUBBLE_MOUND_ID_DATASET | NO | 2 | <H5 file> <H5 path> |
| RUBBLE_MOUND_BEGIN | NO | 0 | N/A |
| NAME | YES | 1 | <string> |
| ROCK_DIAMETER_CONSTANT | YES | 1 | <real> |
| STRUCTURE_POROSITY_CONSTANT | YES | 1 | <real> |
| STRUCTURE_BASE_DEPTH_CONSTANT | YES | 1 | <real> |
| ROCK_DIAMETER_DATASET | YES | 2 | <H5 file> <H5 path> |
| STRUCTURE_POROSITY_DATASET | YES | 2 | <H5 file> <H5 path> |
| STRUCTURE_BASE_DEPTH_DATASET | YES | 2 | <H5 file> <H5 path> |
| FORCHHEIMER_COEFF_METHOD | YES | 1 | <int> |
| RUBBLE_MOUND_END | NO | 0 | N/A |
An example rubble mound implementation with two rubble mounds using a combination of datasets and constants is shown below. Line comments are preceded by a '!'.
RUBBLE_MOUND_ID_DATASET "dana_pt_updated_RM.h5" "/Datasets/ID" RUBBLE_MOUND_BEGIN NAME 'South Breakwater' ROCK_DIAMETER_CONSTANT 1.5 STRUCTURE_POROSITY_CONSTANT 0.4 STRUCTURE_BASE_DEPTH_CONSTANT 2 FORCHHEIMER_COEFF_METHOD 1 !Sidiropoulou et al. (2007) RUBBLE_MOUND_END RUBBLE_MOUND_BEGIN NAME 'East Breakwater' ROCK_DIAMETER_DATASET "dana_pt_updated_RM.h5" "/Datasets/ROCK_D" STRUCTURE_POROSITY_DATASET "dana_pt_updated_RM.h5" "/Datasets/POROSITY" STRUCTURE_BASE_DEPTH_DATASET "dana_pt_updated_RM.h5" "/Datasets/BASE_D" FORCHHEIMER_COEFF_METHOD 1 !Sidiropoulou et al. (2007) RUBBLE_MOUND_END
Last update 9/25/2024
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