The Balancing options allow you to balance cut and fill volumes such that excavated material is used on-site rather than having to be transported away.
When using either of these options you will be asked to define the balancing parameters using the dialog shown to the right
The Parameters group defines the basic parameters for the balancing calculations. The Bulking Factor field defines the bulking factor used for the excavated material. If the fill material is to be compacted using a specialist plant, you should set the bulking factor to be less than 1 to reflect this. The Group Depths checkbox allows you to consider the group depths of triangles in the reference model. The Create Batters checkbox allows you to create batter strings as part of the balancing process.
The Battering group defines the batter string defaults should that be required. The Code field defines the code to be used and the Up and Down fields define the slopes of the batters in the cut and fill directions. The Fan Angle field defines what fanning angle to use at any external corners and should be set in the current angle units. If a corner turns through 90º and the fan angle has been set to 10º, eight intermediate points will be interpolated around the corner. If you do not wish to create corner fans, set the value of this field to be 0. Once the parameters have been defined, the height of the indicating string will be adjusted and any batter strings created.
When constructing buildings, it is often necessary to place the building foundations at a level that minimises the amount of cut and fill carried out. The option Balancing String option allows you to adjust the height of a feature string and create batter strings from that adjusted string such that, when a DTM is formed, cut and fill quantities balance.
When this option is selected, you will be asked to indicate a string representing the area to be optimised and the side that string on which any batters are to be created. You will then be asked to select the reference DTM to which balancing will take place using the normal dialog box and the DTM Balancing dialog box will be displayed.
Normally, this tool expects the points on the string to be in the same plane. When balancing the string, n4ce will form triangles across the centre using its normal algorithm. It may be possible to introduce ridges into the DTM, but you will need to ensure that the triangles will form in the way that you wish by performing a test triangulation. Creating additional points at strategic places may enable you to create the required shape but it may not.
Feature to be Balanced
Balanced without Fan Angle
Balanced with Fan Angle
Note that the heights of the points on the string will all be adjusted by the same height. Therefore, you can use this option to optimise the cut and fill quantities to place a car park where a slope is required for drainage.
The option Balancing DTM allows you to balance an existing design model with another DTM. An example of this would be a small reservoir or slurry pit on a farm. After you have defined the balancing parameters, n4ce will adjust the height to balance the volumes. If batter strings are required, these will be created together with the triangles needed to link the DTM boundary to the batter.
DTM to be Balanced
Balanced DTM with Batters
Note that this option can only be used for a DTM with a single boundary.