Adding Roads and Benches To A Pit Design ©2007 Dr. B. C. Paul {Note – The Name MineSight® and the Program described are property of Mintec Inc – Tucson, Arizona}

What We Have to Start With I have my stage 1 pit surface in my pit optimization file.

I Also Have Topographic Contours of My Pit (Without adjustments for roads or benches)

I Zoom in and Query My Pit Bottom Contour to Get Its Elevation

Pits With Toes, Crests, Berms and Roads are Designed with the Pit Expansion Tool Go to Tool and Drop down the Menu Highlight and Click Pit Expansion Tool

The Routine Will Help You Set Up A New Geometry Object Pick your File Title And hit open

You Need a Line For the Bottom of Your Pit Pick Digitize Click Your Bottom Contour Confirm it is the right line Hit Add

Now Drop to the Lower Box and Set Your Pit Expansion Parameters Specify the start Elevation to match the Bottom of the pit You can tell it to do A bunch of steps at Once (I counted Contours to know I Wanted 19 benches)

Next Step Will Be to Set Benching Parameters Starting Elevation Step Size Berm Width Face Slope Pit Slope

Next I Click On the Required Tab to Tell it How to Bench Up You can choose Which parameters to Specify I specified my 15 meter bench, A 72 degree slope From the toe to crest And a 42 degree Over-all working slope (I could have specified Bench width and let It figure the pit slope) Indicate I want the pit to expand upward and outward starting elev

Next I Open the Roads Tab

I Go to the Naming Field to Name My Road It tells me my road Is unset (surprise-surprise I haven’t set it yet So click Edit)

It Needs Me to Tell it Where to Start the Road Click on the point Symbol and then Point to the spot To begin.

Enter the Road Parameters Give it the starting Level The road width The Grade (0.1 means 10%) And the direction Code 1= clockwise

The View Clicks Back to the Road Tab Only Now the Road is Set

Go Back to the Expansion Screen and Hit Preview

Oh Wow Cool!

Back Out and I Can See My Road and the Toes and Crests I can also see my road width pushed my pit back a little more and cut the Over-all slope.

It Does However End at the Right Level

I Have An Option to Fix That Road Issue I’ll tell it to dock the road with off of the bench width

Click Apply to Add that Steepening Effect

We Can See We Have Taken a Nice Chunk Out of Our Benches with the Road

After Clicking Apply It Asks Us to Name Our Geometry Object

It Also Gives Me A Chance to Name And Save My Instruction Set

I Can Now Click Triangulate to Have it Create a Pit Surface From My Toes and Crests and Road

There is My Triangulated Pit With A Lot of Stuff On at the Same Time

Here is One Item – My Toes and Crest Profile

Here is My Triangulated Surface Of Course What I Really Want is a Smooth Solid Surface

I Highlighted – Right Clicked and Picked Properties Then I used Global Color to Change My Surface Color A Picked Faces Only To get the faces Without the Triangulation showing

If I Turn On My Pit2 Surface I Can See My Benches Surface is Mostly A Little Below the Lerch Grossman Surface

I Can Adjust the Lerch Grossman Surface to be a Little See Through On Object Properties Click the Surfaces Tab and Use the Arrow to increase the Transparency of the surface

Now I Can See My Design Pit Surface if Very Close to the Lerch Grossman Surface

I Can Also See that the Expansion Sometimes Goes Higher Than the Surrounding Surface And sometimes A little lower.

Now I Do Have Some Issues This thing made every bench a common width I will have some working benches wider but I will not provide a working area on every bench Remember I have an option to expand the pit up one bench at a time  This will allow me to deal with working and non- working benches and to fine tune my road.

Lets Consider a Pit with Multiple Bottoms and Something Less than an Ideal Cone Shape Clearly the pit has Multiple bottoms, but Lets also suppose That the 43 degree Slope must Accommodate working Benches.

Hypothetical Bench Set-up Lets suppose that every bench is 18 meters high with a 70 toe to crest slope  This gives about 6 meters over for 18 meters up Suppose a work bench is 34 meters wide and a regular bench is 6 meters wide  Suppose every 4 th bench is a work bench Suppose the road is about 24 meters wide The geometry is not a perfect fit to the pit but it is close

I Get A New Geometry Object for Pit Contours in Edit Mode

Then I Pick the Contour Tool From the Surface Menu

Then I Pick My Pit Surface The blue worm is clicked to pick the surface in the viewer The red box is picked If I want to select from A file list of names

A Click on Preview Allows Me to Peak at My Contours Before Accepting Them Preview contours appear in dark blue

Clicking Ok Saves the Contours Note they have now turned light blue

The Trick to the Irregular Bottoms I will try to create a Pit base at every Bottom and push Back.

Looks Like My Lowest Point is 2072

The Pit Seems to Have Two Main Bottoms – One at 2072 and the Other at 2090

Another Consideration is That I Must Have Enough Room for My Equipment I don’t think I can Get equipment in That little hole at 2072

I Will Put a New Geometry Object for Pit Design Contours Into Edit Mode

Time for the Pit Expansion Tool

I Start With Base Strings. Click the radio button to digitize The base string. Then click the add button Then digitize the base string. Pay attention that you select A geometry that is practical to Dig out and work. Some types Of cuts may have a tendency To be unstable from a rock Mechanics stand point. Try to Add practicality while you Digitize. Note that I dropped the small Pit at 2070 because there Just was no room to work Equipment. First enter the elevation of the Base string.

Enter the Key Information for Pit Expansion Pick the required tab Enter the start elevation Enter the height of the Bench. Indicate how many steps up You want to take at a time Enter the toe to crest slope (different than the over-all Pit slope) Enter the pit slope and bench Width. Note that these Two things are mutually Exclusive – if you know how Wide the bench is you know The pit slope and if you know The pit slope the bench can Only be so wide. Check off which gets priority Finally indicate you want the pit to expand up and out.

Now Put in Road Information Click the roads tab. Select Add (your first road name appears – You can change it if you want. It is initially undefined. Click the edit button to define Things like road start point, Slope, and direction.

The Road Edit Panel Comes Up Click the point icon to let the Computer know you want to Define the starting point for The road. Then point to and click the Starting point for the road and Right click to complete your selection A green dot appears and the Coordinates show in the Box. Enter your starting elevation Your road width Your grade And 1 or 0 to indicate whether The road should advance Clockwise or counter clockwise Finally click ok to initialize your plan for the road

Since I’m Working Off Two Base Strings I Initialize a road for my other Pit too Click add to add a Second road just like I did the first.

I Complete the Process and Now Have Two Road Starting Points Note the old completed Road point is showing Yellow instead of green

I Click Preview and My Pit Expands Up One Bench and I Can See Where My Road is Going

I Can Preview and Move Up Again

And Again At this point I notice my first dissatisfaction because I wanted the road to meet when the pits did which did not Happen.