|
<< Click to Display Table of Contents >> Assigning Dumps to Subsequences |
  
|
|
<< Click to Display Table of Contents >> Assigning Dumps to Subsequences |
|
This topic describes the procedures for assigning Dumps to Subsequences in order to automatically simulate the sequential excavation and dumping of a proposed mining operation. When a Dump is assigned to a Subsequence, material excavated by this Subsequence reports to the assigned Dump.
When Dumps are assigned to Subsequences and the Supersequence is run, each Step (in each Subsequence) is excavated and its material is automatically dumped, the next Step is then excavated and dumped,and this process continues until the Supersequence is complete. The location and form of the dumps is controlled by:
•The setup of the Dump Templates of the Dumps to which the material reports. (the design of individual Dumps)
•The assignment of particular Dumps to particular Subsequences. (which Dumps the excavated material reports to)
•Conditions imposed on particular Dumps which limit their availability (see below).
Dump assignment describes the process by which particular Dump Templates are linked with particular Subsequences in order to achieve the automated excavation and dumping described above. A dump assignment can be as simple as having one Dump Template assigned to a particular Subsequence. However 3d-Digs' Dump assignment allows for assigning several Dumps to a Sub sequence. This list of Dumps is referred to as a Dump Hierarchy. The Dump Hierarchy has a defined order with material reporting initially to the highest order Dump in the Hierarchy. If or when the highest order Dump is full material reports to the next highest order Dump in the Hierarchy.
In addition to the controls on dumping imposed by the Dump Hierarchy and the constraints within the Dump Template, 3d-DigPlus also allows for Subsequence dependent constraints on dumping. The use of Subsequence dependent constraints allows the availability of a particular Dump to be linked to a particular point in a Supersequence. This type of constraint has many applications but in particular it prevents material from reporting to a dump before the Pit floor on which the dump is formed has been fully mined out.
There are several reasons for the use of a multi-dump hierarchy rather than a single dump:
•Frequently a single planned dump will not contain sufficient spoil room to accommodate all material from a particular Supersequence. It is usually not possible to predict in advance the particular Subsequence during the excavation of which the dump will become full. Assigning a hierarchy of several dumps to many Subsequences allows 3d-DigPlus to fill the Dumps in order and automatically determine the points in the Supersequence at which particular dumps become full and other dumps become active.
•In a large long term design the availability of Dumps to Subsequences may be apparent by inspection for the first one or two Strips, however as a simulation progresses deeper into a large long-term Supersequence the availability of Dumps becomes more indeterminate. Hence the requirement for a system which allows for a hierarchy of conditional Dumps. This allows 3d-DigPlus to select from a large list of candidate Dumps and select the highest order Dump which is feasible at any given point in the Supersequence.
Dumps and Dump Hierarchies are assigned to Subsequences. All material excavated from a given Subsequence will report to the assigned Dump Hierarchy. When a Subsequence with an assigned Dump Hierarchy is executed in a Supersequence material is dumped according to the following procedure:
•The first Step of the Subsequence is excavated and reports to the first Dump in the Dump Hierarchy. If this Dump has sufficient room,and it is not subject to an unmet Subsequence condition, all excavated material from the block is dumped.
•If a Dump becomes full during the process of dumping, remaining material from the excavated Block reports to the next Dump in the Hierarchy. At this stage the above procedure repeats (i.e. material dumps until the second Dump in the Hierarchy is full then reports to the next Dump in the Hierarchy).
•When dumping of the first Step in the Subsequences complete the next Step in the Subsequence is excavated and the entire procedure repeats.
•If the highest order Dump is full when a step is excavated, material immediately reports to the next highest order Dump.
•The above steps repeat until the Subsequence is complete.
Important Information - Material Logging and Spoil Room Failure.
In parallel with the above processes, material excavated from a Step in a Subsequence immediately reports to the Contents and Cumulative Cut fields of the assigned Material Log. As material is Dumped it is removed from the Contents and moved to the Cumulative Fill field. If, after processing every Dump in the Hierarchy, there still exists material which has not been dumped this indicates that the proposed Dump Hierarchy has failed to accommodate all material excavated at that point in the Supersequence. If this occurs you will be issued with a Spoil Room Failure warning. In addition material which has been Excavated and not Dumped will remain in the Contents of the assigned Material Log.
On completion of a simulation it is critically important to check all Material Logs (Main Menu: Material/Log Information). The only Material Logs which should have non-zero contents are those for which no dump was assigned (typically coal is just excavated and stored, in such cases all coal Material Logs will have material in the contents). Any waste Material Logs which have non-zero Contents are generally a marker of spoil room failure.
One of the most important benefits of a 3d-DigPlus simulation is the the assessment of dump room over time, identification of dump failure, so it is to be expected that in the course of large and complex tasks spoil room failures will occur and require rectification.
The following section describes the specific process of assigning dumps to Subsequences, more general strategies for this process are described in the section Setting up Complex Simulations.
Dumps can be assigned as soon as the Subsequences have been created, however it is generally best to build the Supersequence prior to Dump assignment.
Dumps are assigned using the Dump/Assign to Subsequences command. This command opens the Assign Dumps dialog:
The Assign Dump dialog has the following components:
•Excavation Template pulldown list. This list contains all Excavation Templates in the current 3d-DigPlus file.
•Subsequences List. When a particular Excavation Template is selected in the Excavation Template pulldown list, all of its Subsequences appear in the Subsequences List. Subsequences in the list are selected individually by point and click, or as groups point and shift/control click. Once selected Subsequences are candidates for Dump Assignment.
•Dump Hierarchy Field. The Dump Hierarchy field contains a list of Dumps. If at Dump Hierarchy has been assigned to the selected Sub sequences, this field will contain the Dump Hierarchy. If no Dump Hierarchy has been assigned, this field will initially be empty. When assigning Dumps a tentative Dump Hierarchy is assembled in this field and then assigned to selected Subsequences. Note that the Dump at the top of the list is the highest dump in the Hierarchy.
•Dump Hierarchy control buttons. These buttons are used to add, delete and arrange Dumps in the Assign Dumps field. When the Add button is clicked it will open the Add Dump dialog:
The Add Dump dialog has the following components:
oDump List. The Dump List contains a list of all Dumps (Dump Templates) in the current 3d-DigPlus file. Individual Dumps can be selected with point and click, multiple Dumps can be selected with point and shift/control click. Once all Subsequences are selected the OK button is clicked and the selected Subsequences are added to the Assigned Dumps field in the Assign Dumps dialog.
oCopy From Subsequence group. Frequently the desired Dump Hierarchy will already be applied to other Subsequences in the current project. When the Use Subsequence checkbox is selected, the Dump Hierarchy is copied from an existing Subsequence. The Excavation Template containing the Subsequence is selected in the Excavation Template pulldown list, the Subsequence is then selected using the Subsequence pulldown list. When the OK button is clicked, the Dump Hierarchy from the seed Subsequence is added to the Dump Hierarchy field in the Assign Dumps dialog.
oAdd Buttons. The slected Dump or Dumps are added with the Add Top and Add Bottom buttons. These buttons place the new dumps at the top or bottom of the Dump Hierarchy.
Once a group of Dumps is in the Assign Dumps field an individual Dump can be selected by point and click, once selected it can be manipulated with the Up, Down and Delete buttons. These buttons are used to adjust the position of individual Dumps in the hierarchy, and to remove Dumps. Existing Dump Hierarchies can be edited and have additional Dumps added using the above procedures.
•Filters Group. Excavation Templates for long strips with many block lines, and many passes, often contain a very large number of Subsequences. It is often the case that Subsequences within a particular Block range, or from a particular Pass share a common Dump Hierarchy. Using Filters the full set of Subsequences for a Excavation Template can be reduced to those selected by the filter criteria.
•Assign Button. Once the required Dump Hierarchy is assembled clicking the Assign button will assign the Dump Hierarchy to the selected Subsequences. Note that once a Dump Hierarchy is assigned it can readily be modified and edited with the above procedures. Selecting a Subsequence with and assigned Dump Hierarchy will result in this Hierarchy appearing in the Dump Hierarchy field.
•Excavation Dependencies Button.The Excavation Dependencies Button allows one or more Subsequences to be assigned to a Dump as Dependent Subsequence. When a Dump has a Subsequence assigned in this manner no material will be dumped within this Dump until the Dependent Subsequence/Subsequences have been fully excavated. Excavation Dependencies are a very powerful function when multiple Supersequences are to be used to look at various scheduling options. This subject is covered in the following section.