When a project is analyzed and failed, users usually get confused and have no idea on how to troubleshoot the error behind the warning/error messages.
Therefore, this guideline will help users to have better understanding on why the analysis failed and how to correct it to ensure a successful analysis to meet the satisfactory design.
Flowchart below can be use as reference when the design analysis failed:
Troubleshooting Analysis Failure #
Unable to find suitable IL configuration based on the constraints #
Try to unfix the IL and/or ensure drain size fulfill site condition, and/or make sure that the drains/pipes are going from higher ground to lower ground, or use cascading drains if applicable
Suggested Solutions for Issue 1
i. Check for any outrageous drain size
ii. Review ILs; unfixed/adjust invert level
Steps to applied:
- Go to Drain > Spread Input > Dimension > Change drain size
- Analyse > analysis successful > OK
- Review outputs > Export results (if require)
Other alternative is to change the maximum depth in Parameter Settings
- Go to Options > Project Parameters > Drainage
- Design > General > Max Depth (you probably need to increase the value, given all the constraints)
Fixed drain height is larger than fixed depth of connected node #
Suggested Solutions for Issue 2
i. Review ILs; unfixed/adjust invert level
ii. Proposed smaller drain size and/or do not fix drain size
Steps to applied:
- Go to Drain > Spread Input > Invert Level, change iterate ‘NO’ to ‘YES’
- Analyse > analysis successful > OK > export results
OR
- Go to Drain > Spread Input > Dimension > use smaller drain size and/or do not fix the drain size
- Analyse > analysis successful > OK > export results
Peak Flow Higher Than Capacity #
Suggested Solutions for Issue 3
i. Review fixed drain size and enlarge dimension
ii. Set iterate drain dimension from ‘NO’ to ‘YES’
Steps to applied:
- Go to output > excel report > check remark and identify which drain have less capacity than peak flow
- Go to input > drain > spread input > dimension > enlarge drain dimension
- Analyse > analysis successful > OK > export results
OR
- Go to output > excel report > check remark and identify which drain have less capacity than peak flow
- Go to input > drain > spread input > dimension > iterate from ‘NO’ to ‘YES’
- Analyse > analysis successful > OK > export results
Gradient is out of range #
Suggested Solutions for Issue 4
i. Check gradient iteration
ii. Check minimum/maximum gradient set in parameter (drain type basis)
Steps to applied:
- Go to drain > spread input > gradient > change iterate ‘NO’ to ‘YES”
- Analyse > Analysis successful > Review Outputs > export results
OR
- Go to ‘Project Parameters’ > Drainage > Drain types > change minimum and maximum gradient (change per drain type basis)
- Analyse > Analysis successful > Review Outputs > export results
Velocity out of range #
Suggested Solutions for Issue 5
i. Check gradient iteration
ii. Check minimum and maximum velocity in parameter
Steps to applied:
- Go to drain > spread input > gradient > proposed a suitable gradient value or change iterate from ‘NO’ to ‘YES’
- Analyse > Analysis successful > Review Outputs > export results
Note:
- This suggestion will depend on situation whether the velocity is less than the minimum velocity or more than maximum velocity set in the parameter
- If the velocity is less than the allowable minimum velocity, user may propose a steeper gradient and/or propose a smaller drain size
- As for velocity more than the maximum allowable velocity, user may propose a gentle gradient and/or propose a bigger drain size
- By applying suggestion above, user will be required to analyse the project and see how the velocity changes and make appropriate changes to achieve satisfactory design
OR
- Go to ‘Project Parameters’ > Drainage > Design > change minimum and maximum velocity to suit the project needs
- Analyse > Analysis successful > Review Outputs > export results
Some drains ILs are set higher than permissible level in relative to the ground #
Suggested Solutions for Issue 6
i. Review ILs; unfixed/adjust invert level or change ‘Min Cover of Culvert,m’ at parameter setting
Steps applied:
- Go to drain > spread input > check fixed invert level > try to unfix; change iterate ‘NO’ to ‘YES’
- Analyse > analysis successful > review outputs > export results
OR
- Go to Project Parameters > Drainage > Design > change ‘Min Cover of Culvert,m’ (if necessary)
What to do if you have no idea how to troubleshoot, there are just too many failures and errors! #
- Check the ground level, make sure that they are reasonable. You can also check the Long. section to detect the abnormality of the Ground Level. i.e: all nodes are 0, but the final node is 100m, this is definitely not reasonable
- Set iterate dimension=NO for all drain/pipe dimensions, use your hand picked dimension first to analyze, and see what do you get from there
- Try not to constraint the IL too much. Try to set only the starting node invert level and other very essential ILs, and let the computer figure out the rest.
- If you really want to control how the drain/pipe flows, you can set the drain/pipe gradient to a fixed value, which is easier to set than individual drain/pipe start/end IL.