I often get asked how many Waste or Borrow Sites should I create for a Project mass haul analysis.
The answer to this question is create as many Waste and Borrow sites along the route as you can potentially find. Create a Haul Road pattern that allows the Waste and Borrow Sites to be connected to the main alignment in as many places as the materials / exits as possible. Let the analysis then work out which ones to use based on where it needs the materials available or needs to waste the excess materials created, and let it determine the cheapest solution from the options provided. If you need to for example use Waste Site A first and then Waste Site B second then you can weight the sites using cost, so that the optimization will fill Site A first and then move onto B because it is the next cheapest option.
The other question that I get all the time is that “we dont want to haul the material in two parts like the mass haul calculation seems to need it - One along the alignment to get to the exit point or from the entry point and the second from the exit / entry point to the waste or borrow site because we pick the material up on site using On Road Trucks and haul it direct on one pass to the waste or from the borrow site”. In this case I tell people to draw a haul road parallel to the main line on left and right side of the alignment, and then draw small connectors from the Haul Road along the alignment to the main alignment wherever they want to bring material onto the alignment - you can have as many Entry and exit points as needed. Then connect the long haul lines along the alignment to the real haul roads from the site to and from the waste or borrow sites.
In this way the Waste or borrow material will leave the alignment or join the alignment only for a few meters of On Site Haul, leaving the remainder to be Haul Road Haul. You will always have some On site distribution of material (Push out by a dozer or grader etc.) so that will be the small on site movements - the remainder will be picked up by the long haul assets (Scrapers or ADTs or Trucks) for the remainder of the hauls, so you will get an accurate estimate of the work for each type of asset.
Using this method I have found TBC can effectively model what people are looking for in the Mass Haul Analysis.