Mass Haul Diagram

ngnrd - PE said:

A negative value at the end of the curve indicates that borrow will be required to compete the fill.

A positive value at the end of the curve indicates that a waste haul will be necessary.

So, for question #6: Diagrams A and B indicate that the operation will need to include a borrow haul (there is a material deficit). Diagram C indicates that there will need to be a waste haul (there is excess material on the project). Diagram D indicates a balanced material situation (although it may be more feasible to perform both borrow and waste hauls during construction based on factors not considered in this question). So, the answer should be D (all of the above).

For "general shape" type questions (like #7), just remember that the VALUE of the PGL curve at a given point is directly proportional to the SLOPE of the mass diagram curve at that same point. [ e.g., at the beginning, the value of the PGL is positive, so the slope of the MD must be positive, so you immeadiately eliminate MD C, as it begins with a negative slope] But, this will only provide the general shape of the MD curve, and not values. So in the case of question #7, both diagram B and diagram E have the same shape, which both correctly relate to the PGL.

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