Physical Alternative for Manholes
The physical alternative editor for manholes is used to create various data sets for the physical characteristics of manholes. The following columns are available:
| Column | Description |
|---|---|
| ID | Displays the unique identifier for each element in the alternative. |
| Label | Displays the label for each element in the alternative. |
| Bolted Cover | Indicates that the associated manhole has a bolted cover. If the manhole cover is bolted, then the hydraulic grade line is not reset to the rim elevation at the downstream end of the upstream pipes in the case of a flooding situation (the calculated HGL being higher than the rim elevation). |
| Width | Displays the width of each box manhole in the alternative. |
| Length | Displays the length of each box manhole in the alternative. |
| Diameter | Displays the diameter of each circular manhole in the alternative. |
| Structure Shape Type | Indicates whether the manhole is circular or box shaped. Clicking a field displays a list box that allows you to switch between the two. |
| Area (Constant Surface) | Lets you define the area in which ponding occurs at the currently selected element. It is available only when the Surface Storage Type attribute is set to Ponded Area. |
| Surface Storage Type | Contains list boxes for each manhole that allow you to specify whether the manhole uses the Default Storage Equation or a Surface Depth-Area Curve. |
| Surface Depth Area Curve | Clicking the Ellipsis (…) button in this field opens the Surface Depth-Area Curve editor, allowing you to define the Surface Depth- Area curve for each element in the alternative that uses the Surface Depth-Area Curve Surface Storage Type. |
| Elevation (Rim) | Lets you define the top elevation of a manhole structure. This elevation is typically flush with the ground surface. However in some cases, the rim elevation may be slightly below the ground surface elevation (sunk) or slightly above the ground surface elevation (raised). |
| Set Rim to Ground Elevation | Enables or disables a data entry shortcut. If the box is checked, the manhole rim elevation is set equal to the ground elevation automatically. |
| Elevation (Invert) | Lets you define the elevation at the bottom of the manhole. |
| Elevation (Ground) | Displays the ground elevation for each node in the alternative. |
| Headloss Coefficient | Lets you define the headloss coefficient of each manhole in the alternative. This column is only available for manholes that use the Standard Headloss method. |
| Headloss Coefficient Start | Lets you define the headloss coefficient of the element upstream of the manhole. This column is only available for manholes that use the Generic Headloss method. |
| Headloss Coefficient Stop | Lets you define the headloss coefficient of the element downstream of the manhole. This column is only available for manholes that use the Generic Headloss method. |
| Absolute Headloss | Lets you define the absolute headloss of manholes in the alternative. This column is only available for manholes that use the Absolute Headloss method. |
| Headloss Method | Lets you specify the headloss method that is used by the associated manhole. |
| ID | Displays the unique identifier for each element in the alternative. |
| Label | Displays the label for each element in the alternative. |