Structure Costs

Structure costs are those that are associated with culverts, bridges, tunnels, and retaining walls. To view or edit these costs, select the relevant tab in the Cost Parameters dialog.

Culvert costs

A culvert consists of one or more channels (or cells) that allow waterways or other features to pass under a route, usually at a lower cost than a bridge.

A crossing that uses a culvert can alter the cost of the alignment by:

• reducing the quantity of fill required by the volume of the channels

• the cost of the culvert; dependent on the length, diameter, and type of culvert

• the minimum cover of earth required to spread traffic load

• the cost of the portals (where each channel enters and leaves the earthworks)

To enter or edit culvert costs, select the Culvert tab in the Cost Parameters dialog:

You can enter multiple types of channels for use as culverts. The name of the culverts must be unique

To edit an existing entry, click the cell that you want to change. To add or remove an entry, right-click the table and then make your selection.

Note: There is no default setting option for Culvert.

When engineers put watercourses in culverts, they tend to straighten them out to eliminate unnecessary bends that can create blockages and cause flooding. Consequently, the length of the channel required is somewhere between the actual length of the watercourse and the straight-line distance between the entry and exit portals to the earthworks. Quantm Desktop software uses a weighting factor to distribute the length between the path distance and straight distance along the watercourse. A value of 0% would follow the watercourse path precisely, and a value of 100% would estimate the length as the straight-line distance. The default is 100%.

Enter the percentage value for weighting in the Weighting field or use the slider to define the value. The value chosen will be applied to all culvert types defined within the Culvert tab.

Note: If you are not going to require culverts within your study area you do not need to define any Culvert types.

Bridge costs

The cost of bridges assumes a fixed cost per unit area of deck. The area of deck over the feature being crossed is increased by the slope of the abutments at either end. To enter or edit these costs, select the Bridge tab:

The list on the left shows the bridge types.

To edit an existing entry, click the bridge name or abutment slope value that you want to change. To add or remove an entry, or to change the default, right-click the table and make your selection.

The default bridge type, indicated by a blue check mark, is used where a bridge type is required but none is uniquely specified.

Quantm Desktop allows the user to define a varying cost per unit area of deck, depending on the height of the bridge to be constructed. For example, a 10m high Concrete deck bridge will cost less to construct than a 20m high Concrete deck of the same span. Hence, the list on the right of the Bridge tab shows the varying costs for bridge construction at the defined vertical heights.

To add varying bridge costs depending on construction height, complete the following:-

1. Select a Bridge type from the list in the Name list.

2. Select the max height m (ft) or $/m2 (yd2) that you want to edit.

3. Enter your value

4. Select OK to save your entry.

To add a cost per height value for a bridge, right-click in the max height or $ cells and select New. To remove an existing cost per height value for a bridge right click and select Remove. You must have at least one cost per height value present for the bridge construction cost. If only one is present, then the default height for the bridge is 9999 (for metric units or 32805.12 for imperial units). This allows Quantm Desktop to construct bridges at any height (i.e.assumed an infinite height up to 9999 above the terrain) with your single cost value.

Tunnel costs

To cost tunnels, Quantm Desktop software assumes a varying cost per unit distance. The varying cost allows the user to increase the construction costs for longer tunnels as opposed to shorter ones. In addition, a fixed cost for portals is included which also covers setup costs. If setup costs were not taken into consideration, and tunnels were costed purely on a $/m (ft), you could underestimate the cost of a very short tunnel. You must have at least one cost per tunnel length value present for the tunnel construction cost. If only one is present, then the default length for the tunnel is 999999 (for metric units or 3280512 for imperial units). This allows Quantm Desktop to construct a tunnel at any length (i.e. assumed an infinite length up to 999999) with a single cost value.

The material excavated from the tunnel is assumed to be entirely usable for fill. The volume is calculated from the nominated cross-sectional area and the tunnel length and is either removed for use as fill or dumped.

To enter or edit these costs, select the Tunnel tab:

The list on the left shows the tunnel types.

To edit an existing entry, click the tunnel name that you want to change. To add or remove an entry, or to change the default, right-click the table and then make your selection.

The default tunnel type, indicated by a blue check mark, is used where a tunnel is required but none is uniquely specified.

The list on the right of the Tunnel tab shows the allowable maximum length for the selected tunnel type.

Retaining wall costs

To enter or edit the costs associated with a retaining wall, select the Wall tab:

The default wall type is indicated by a blue checkmark and is used where a wall type is required but none is uniquely specified.

To edit an existing entry, click the cell that you want to change. To add or remove an item, or to change the default, right-click the table and then make your selection.

Next topic: Object Data