Tutorial M04

Introduction

In this module, bridges are represented within the 2D domain. Topographic changes are made to cut through the road and a time series data output created to gain information on a range of hydraulic parameters of the bridge.

The GIS layers are:

• TGC layers:

1. 2d_lfcsh: A layer used for modelling 2D flow under and over bridges, pipes and other obstructions across the waterway.
2. 2d_zsh: A layer used to modify Zpt elevations using points, lines and polygons.

• TCF layers:

1. 2d_po: A time series data output from 2D domains, for a range of hydraulic parameters.

Module 4 builds from the model created in Module 2. The completed Module 2 model is provided in the Module_04\TUFLOW folder.

GIS Inputs

Create, import and view input data:

• QGIS

Simulation Control Files

TUFLOW Geometry Control File (TGC)

1. Save a copy of M02_001.tgc as M04_001.tgc in the Module_04\TUFLOW\model folder.
2. Open the M04_001.tgc in a text editor and add the additional lines below the Read GIS Z Shape == gis\2d_zsh_M02_rd_crest_001_L.shp | gis\2d_zsh_M02_rd_crest_001_P.shp command:
   Read GIS Z Shape == gis\2d_zsh_M02_cut_002_R.shp ! GIS layer used to define excavation through embankment
   Read GIS Layered FC Shape == gis\2d_lfcsh_M04_bridge_001_L.shp ! Layered flow constriction representing 2D bridge losses
   
3. Save the TGC.

The 2d_zsh_M02_cut_002_R.shp file from Module 2 is first read to cut through the embankment. The 2d_lfcsh is then read to represent the structure. The order is important as the 2d_lfcsh has an invert value of 99999, it uses the underlying elevation values to represent the invert of the 2D bridge. If this was read before the 2d_zsh file, it would use the elevation of the embankment crest.

TUFLOW Control File (TCF)

1. Save a copy of M02_5m_001.tcf as M04_5m_001.tcf in the Module_04\TUFLOW\runs folder.
2. Open the M04_5m_001.tcf in a text editor and update the reference to the TGC:
   Geometry Control File == ..\model\M04_001.tgc ! Reference the TUFLOW Geometry Control File
   
3. Update both the 2d_po line and point files:
   Read GIS PO == ..\model\gis\2d_po_M04_001_L.shp ! Reads in plot output line
   Read GIS PO == ..\model\gis\2d_po_M04_001_P.shp ! Reads in plot output point
   
4. Save the TCF.

Running the Simulation

1. Save a copy of _run_M02_HPC.bat as _run_M04_HPC.bat in the Module_04\TUFLOW\runs folder.
2. Update the batch file to reference the M04_5m_001.tcf :
   set exe="..\..\..\exe\2023-03-AA\TUFLOW_iSP_w64.exe"
   set run=start "TUFLOW" /wait %exe% -b
   %run% M04_5m_001.tcf
   
3. Save the batch file and double click it in file explorer to run the simulation.

Troubleshooting

See tips on common mistakes and troubleshooting steps if the model doesn't run:

• QGIS

Check Files

While the model is running, review the added features are specified correctly:

• QGIS

Results

When the model is finished, review the results:

• QGIS

Conclusion

• A 2d_lfcsh was supplied and used to represent a bridge structure in the 2D domain. The invert level of this structure was implied from the underlying topography created by cutting through the road embankment.
  
• 2d_po structure group was setup and described to enable more detailed result viewing through the structure.
  
• Check files were used to review the 2D bridge application.
• Results were visualised to show water passing through the 2D bridge and the structure group results were assessed.
  

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