Many users of GEOVIA Surpac struggle with how to effectively select specific drillholes when completing database tasks such as display, compositing or data extraction. To view or process a select number of holes requires some setup in the collar table and knowledge of Surpac’s Drillhole Constraint functionality. This is often an overlooked and forgotten area of the Surpac toolset, but yet can provide value by streamlining workflows. This GEOVIA blog post will now discuss the setup and methodology to utilise this capability.
Workflow: Drillhole Constraints
Preparation of the collar table
Before using the drillhole constraint tools, it is recommended the user should first ensure an optional field exists in the collar table (not mandatory). This field will serve as a flag, to select holes of different types, categories or areas (e.g. Hole Type, Year Drilled etc.). For example, below this Collar table has the optional field ‘hole_type’, which can be used with drillhole constraints to select only the ‘DDH’ holes.
The drillhole constraints functions are located under Database > Display menu.
To create a drillhole constraint, go to Database > Display > Add new constraint
The form below also appears in many other functions in GEOVIA Surpac, such as compositing, drillhole display and data extraction functions. Drillhole constraints allows users to select or process a group of drillholes in the database. It works in a variety of ways, for example:
1) If left blank all holes in the database will be selected.
2) Select holes by a flag field (e.g. Hole Type) in collar table. For example, to only select RC holes in the database.
Note: Using the Save and Load buttons a *.dbc file (drillhole constraint file) can be saved and re-loaded. This feature is particularly useful if the desired constraint is complex and made of many rows, as the user wouldn’t want to manually re-add rows and redefine the constraints each time the constraint is required.
3) Select holes based on a range of hole ID’s. For example, only the select holes between JRC060 and JRC090.
Note: The operand symbols in the above form (e.g. >=), will also work with alpha characters.
4) Select holes based on elevation. For example, only the select holes by collar elevations within a range (e.g. in a bench).
Additionally, as well as knowing how to apply a drillhole constraint, it is equally as important to know how to remove one.