Mass Calculation¶

Gemini Terrain uses the cross-section method for road mass calculations. This method is described in more detail in Cross-Section Calculation Method. This chapter covers mass balance and the predefined mass types for roads.

Correction Factors¶

To achieve calculation results as close to reality as possible, you must correct the calculated masses for factors such as mass expansion during rock blasting and shrinkage during extraction, transport, and placement.

Correction factors for mass calculations

Figure: Correction factors for mass calculations

Mass Balance¶

During the design phase, the most important task is to calculate the mass balance. The mass balance is determined by comparing the mass requirement (designed placed masses) with the available masses (designed solid masses) along the road alignment.

It is common to present the masses graphically using a bar chart (mass diagram). The height of each bar is determined by the calculated volume (\(V = A \cdot L\)). The volume is given as unit mass or as designed placed masses (pam³).

Mass Diagram¶

Bar chart showing the mass balance

Figure: Bar chart showing the mass balance

Info

Accumulated mass balance, that is, the sum of all masses from the start of the road to the point where the volume is plotted on the curve, provides a better overview.

Accumulated Mass Balance (Mass Profile)¶

Graphical representation of accumulated mass balance

Figure: Graphical representation of accumulated mass balance

Predefined Mass Types¶

Gemini Terrain includes predefined mass types for automatic road calculations. The mass types are illustrated below.

Description	Unit	Note
Soil cut	Volume
Topsoil	Volume
Topsoil fill	Volume
Rock cut	Volume
Deep blasting	Volume
Area blasting	Area
Fill	Volume
Ground leveling for mass replacement	Volume
Mass replacement	Volume
Road surface	Slope area
Road surface	Volume
Base layer	Slope area
Base layer	Volume
Sub-base	Slope area
Sub-base	Volume
Soil cut	Slope area
Rock cut	Slope area
Fill	Slope area

Soil Cut¶

Sketch: soil cut

Figure: A = Soil

Topsoil¶

Sketch: topsoil

Rock Cut¶

Sketch: rock cut

Deep Blasting¶

Sketch: deep blasting

Area Blasting¶

Sketch: area blasting

Fill¶

Sketch: fill

Next Step¶

Once the masses are calculated, you can export the road model to field. See the overall work process for road design.