August, One Week Later.

TOOK A WEEK OFF from digging while the youngest grandchild, Ruby, was down with her mom.  It was great to see Sarah and read her some poems.  Ruby wasn't too sure of me unless I had food; then there was no doubt her grandpa was all right.  Sarah helped us with putting videos on the internet and wants to help with the blog-site.

I need to do a little more choreography and get some more interesting video.  It is hard to make one dig look different from the other.  I can change light and change camera position.

Charlie and I had one more dig.  Now I know why I didn't mind too much not to dig for a week.  More problems in the SE corner, behind the large wall rock.  I thought I had filled the gap between the south end of the big wall rock and the South Wall by wedging that basketball-sized rock in there, but when I removed the mud from the south wall the rock I wedged there moved.  Now this was a chair-sized rock and looked like it was holding back a lot of mud and rubble and I was stacking a rock wall on top of it to hold up backfill.  I had my 25 buckets sent up the shaft and had just my four extra to fill.  So I got down in the hole below the rock pile for four more buckets and gouged out a depression for it to fall into.  I then removed all tools from the hole and, climbing as far up as I could, I kind of started poking blind with a seven-foot piece of rebar to see what wanted to fall down into the hole from behind the rocked and shored East Wall.

It makes a person a little nervous being 75 feet deep and trying to start a slide at the bottom...  The rule is, though, that I don't leave anything loose about me as I dig down.  All muds must be removed to determine the foundation of any rock.  Any wall in question must be shored and cross-braced or a cement and steel support wall be built under and in front with 100% back-fill.

So sure enough, little by little by little, the boulder rolled out of the SE corner and plopped down into the hole, even rolling over and giving a tap to the bottom foundational rock that sent a shudder up the rocks I was standing on.  I could hear more mud and rock plopping down and peered around the corner to see my stacked wall hanging in mid-air.  I kept poking blind because I didn't want to get down in there.  If there was going to be a disastrous slide I would definitely be better off above it...  I heard a few more rocks fall but nothing that I hadn't stacked.  So I left the dig to do whatever it was going to do.

Now, two days later, I will go down and see what there is to see.  I need to get that boulder out of there.  Will it break up with the sledge?  I would have to be below the slide, swinging the hammer.  Is it too big to lift?  And even if I can lift it, where do I put it?  it's too big to go up the shaft, much less through the collar.  I have to find some way to building a reinforced cement wall to keep the rock-pile stable and get the wall built before any major movement occurs.

~SIX HOURS LATER~
That's not going to work.  The whole rock pile below the shoring is unstable.  All visible rocks and boulders are loose.  The big wall rock is just hanging there, still cross-braced but with nothing underneath.  This is a complication of the worst sort.  

~CONTINUED~
I had gone down there and examined the boulder and rocks that had slid down, having given it a couple of days to do whatever it was going to do.  It didn't look too bad; nothing much came down, more than I had stacked up as backfill.  I could even possibly roll the largest boulder into a hole on the west side if I could break a point off and make it smaller.  

So I kneel down under that 1/2-ton wall rock like an offering to the stone god and roll away and pick up all loose rocks out of the mud, manage to get the 300-pounder iron-barred around so I can get some kind of swing with the sledge. 

That's me:  the hammer, the bar, and some boulders stuffed into a 5'x4'x4' cranny in the SW corner at the bottom of an undercut boulder pile, whaling away on the biggest rock, trying to make it small enough so I can wrestle it around and park it on the west side up the shaft, and then something above me moved.
Now this digging at the bottom of an active sinkhole is always an adrenaline charged work.  If I don't feel it, I know I'm being way too casual.  In fact, I'll charge myself up any way I can, even raise my debt limit, to keep myself from being casual about even one step!  So, with zero thought process my hand was planted on what had moved (which was the 400-pound rods under the 1000-pound wall rock) and hardly before it stopped moving I had catapulted myself 5 feet up the shaft and was ready to climb the next seventy.  All was loose below me.  Charlie was parked above the collar, keeping an eye on things that he could see.

All was still, except my heart and any other body part that could vibrate from the adrenaline rush.  I sat, stood, or squatted on the step above, perched on a bedrock ledge.  Hmm.  Wow!  Gosh!  What now?  Yep -- the big one's hanging.  Oh my!  I am so little and they are so big, but here we all are.  It was obvious by the second or third thought through my head that I was not going back down into the hole to dig until the wall rock was 100% stablized [Editor's Note:  VERY GOOD IDEA.]

How to do it?  fill the space around it with concrete and rock -- maybe.  Drill, and blast, and fire?  Can I get down in there to brace to the South wall?  If it slipped would I be safe in that cranny?  Could I get there fast enough?  What would happen if I lassoed the nose of that rock with a sling and rolled it back with a hard winch?  What do I pull from?  How can there be such a large rockpile at the bottom of a 4'x4' hole and where am I going to put them so they won't just keep fallowing me down as I dig?  ...Like monstrous gravitationally-enslaved beings dogging my elbows...  All these questions need answers that only I can find.  I pulled myself back up the culvert to the surface, following Charlie to talk and think it over and find the next thing to do.

Eventually, it becomes obvious that, since the shored wall above the large wall rock was mostly just a rock cairn, I could build another wall behind it that would be two to three feet further East.  I would start back up at the ledge level, 10 feet below the collar, and tier by tier with concrete, steel, and stone build the wall down until I was entirely behind the whole rock pile and hopefully have a place big enough to get the boulders out of the way for good.  Of course I don't know what other rock I may find that is equally precarious, but the hole is as dry as it ever gets right now and the wall will have to be built sooner or later.  I was hoping to build it from the bottom up, but that isn't going to happen.

So the next dig found Charlie and David packing in more concrete mix.  Twenty bags on the pallet, ready to mix.

Going Deeper

August 14, 2011

Eight digs later and somewhere around 200 buckets deeper.  I cross-braced the wall boulder, found another one under it with a long, peaked top sitting perpendicular under the big one, and that one sat nicely on a good block that was sitting on bedrock that appears to be an igneous wall, and so on for another two rocks.  There was a mud pocket in the SE corner behind the large wall boulder, that a basketball sized boulder rolled out of starting a mud slide and sending me scurrying back up the shaft today.  It turned out well.  I was able to use the rock to wedge brace a gap in the rock pile between the large wall boulder and the south wall.  I added another step by dropping a peaked rock with a flat bottom up, into the air hole beneath the steps along the descending marble west wall.

Boulder by boulder I descend, never knowing when I dig the mud away if I will really find the rock pile still sitting on something stable.  Now I seem to be headed down into a mud pit.  Found air space in the SW corner but no air-flow.  Did a temperature gradient from top to bottom?  65 degrees  above the shaft under the roof.  41 degrees at the 30 foot level and 40 degrees below the collar.  This winter the same readings were: 35 degrees above the shaft below the roof, 38 degrees at the 30’ level, and 39 degrees below the collar.  I believe these temperatures indicate air going into the shaft in the winter and coming out now in the summer.  There was always air-flow through the dissolution cracks in the marble of the adit and it also seems to be weeping through ceiling spaces below the collar.  I have been filled with doubts this week that I have somehow missed the way in.  The adit air-flow is almost 30’ above me!  Yet the mud and rock I’m digging in is still soft and hollow and filling in a void that existed before the collapse of the sinkhole covered the boulder pile I’m digging down alongside.  Nothing to do but to dig on.  No direction to go but down.

        Too much work,

        Not enough rest;

        Too much chocolate,

        Not enough sex;

        Way too much of not knowing

        What comes next.

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Just want you to know that several pictures in the bottom scroll line are not us, but interesting nonetheless.

The Mistress-- the way she was

More buckets--August 2011 begins

Aug 2, 2011

I wasn’t 74 buckets from getting in but I’m 74 buckets closer to being in.  Not just buckets of mud either..We took out ten buckets of just rock from the replenished cairn.  Replenished after the mud slump from behind the east wall ten (?) weeks ago.  It allowed the rock pile to settle down replacing the mud as backfill.  We moved the rocks up to the surface to make room for two boulders from the dig ten feet below.  My bedrock floor, marble, is dropping straight down instead of the 70degrees East incline of the geologic strata.  The boulders were my steps to get me out of the hole as each bucket was moved up to the lifting cable.  The boulders had to be replaced by steps.  I was blessed with 2 small anomalies on the west wall that allowed me, with some strategic shaping with the pruning saw, to hold the west end of the steps.  The east end fit into cracks in the rock pile on the east side.  Rearrange the rocks a little bit, cut everything just the right length and just the right shape, and, presto!, 2 more steps fit into the rocks as we descend down this sink-hole into the unknown chambers waiting below.  The upper step wasn’t quite perfectly horizontal, but it will have to do.  If it’s a slipping problem I can put a slight wedge on it.

Now in touching on safety, my chief concern this season has been shoring up the west wall from what started out as shored rock and clay, but is now boulders too big to move on the north end.  I need to shore over to the southward sloping wall.  The south wall not only slopes angling down to the south but also slopes down to the west, striking SE to NW, and so I can lock the south end.  I can lock the south end of the shoring from coming out but not down. Without backwards pressure, the shoring planks want to settle down and lose their tight grip on their north end.  Creative cross-bracing over to the rough marble of the west side that keeps upward pressure on the east wall has helped.  The only back-pressure I’ve gotten is when thirty buckets of mud flowed out from behind the wall one day, and my rock cairn settled down until a big rock wedged itself somewhere behind the wall.  The rest of the rocks slowly (over weeks) settled into place and things seem to have stopped moving. 

Now I have come down to this big boulder, 4’ long.  My wall is now sitting on that, I am digging down alongside, about 2’ so far, and have to ask myself what is this rock sitting on.  The one above is sitting on it, and the one above that is sitting on that one, and there are two or three more up to the bedrock of the NW corner, twenty feet above, just below the collar where the culvert to the surface is attached.  (Wow! What a wonderful poetic sentence!)Could this rock just tip over, falling out of the east wall onto the west side, loosened by my digging, opening up a huge gap at the bottom of the east wall, and activating the sink-hole?  Now, I have had to ask this about every rock above this one and the answer so far has been, “No, it’s sitting on a bigger one.”  But, this one is the biggest, so if something goes wrong it’s a bigger wrong.  What these boulders appear to be are pieces of a dike broken by faulting.  They seem to fit together and are not much moved from the original placement in relation to the marble.  The dissolution of the marble alongside the dike allowed the fault fractured rocks to fall down into the descending passageway, and opened up a hole for the North side talc seam to wash and slump down over the rock rubble, leaving the larger pieces of the dike practically in situ.  Which all may be true but it still doesn’t tell me what it is sitting on, and if it is al all inclined to stay put.

At this point, the upper corner of the south end is locked behind the sloped ceiling (south wall), chinked with a wedge rock.  The north end at dig level is pointed with mud back under the point.  I haven’t found the bottom in the middle.  I am encouraged by the fact that the rock seems to be right where it has always been during the whole process of cave and sinkhole formation,  and collapse  to the surface.  If it went through all that and stayed put, perhaps it will suffer my shoveling in the same spirit.  I think I’ll add a cross brace anyway, a sturdy one.  Here’s hoping my Mistress will be kind to me!!

The last day of July was a great dig.  Laptop and cameras up and running and we got some video on the hard-drive.  Hole ddrying out and I can even stand and dig.  I can’t wait to see what the next 100 buckets will result in!