<< Click to Display Table of Contents >> Navigation:  User Manual > Truck & Shovel Simulation > Setting up Haul Roads and Accesses > Geometric Design of Haul Roads and Accesses > Creating a Road on Terrain > Excavation Access Roads > Excavation Access - Haul Down Option

The previous example involved at Haul Up ramp. The Ramp was excavated progressively during excavation of the strip, and all waste material was hauled up the newly excavated ramp. Another common mode of operation is referred to in 3d-DigPlus as a Haul Down Ramp. In this case the ramp exists complete at the start of excavation and material is hauled from the excavator to the crest of the ramp and down to the pit floor or some other lower level. The following figures illustrate this situation:

 

Longitudinal Section Through Ramp:

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In the above example loaded trucks travel from the excavator to the Crest of the Excavation Access road, then Down the Access road to the Main Haul Road.

The design and set up of a Haul Down ramp is the same as that for the Haul up Ramp described above. There is typically a ramp designed into the Highwall of the Pit Shell. The Horizontal alignment is placed along the centreline of this ramp. The Vertical Alignment is placed to coincide with the ramp design in the Pit Shell. As excavation proceeds down in lifts the upper portion of the ramp is removed by the excavation and the Active (lower) portion becomes progressively shorter. The Crest of the Excavation Access Road for a given lift is the top of the Active Portion. Trucks travel form the current Block in a Subsequence, via the Excavation Manifold, to the Crest of The Excavation Access Road then down. Throughout the Active Portion of the Excavation Access Road the Vertical Alignment and the topography coincide within a small tolerance. Beyond the Crest the Vertical Alignment is above topography. 3d-DigPlus uses this relationship to establish the location of the Crest of the Excavation Access road for the current lift.  As with Haul up Ramps, it is important that the Vertical alignment is placed to coincide with the design ramp.

This video clip demonstrates a haul Down Excavation Access road: