May 20, 2012
Back in April, we took advantage of the soft spring ground to get a start on widening our new entrance. When we applied for a Conditional Use Permit allowing us to dedicate a portion of this land as a natural burial cemetery, the county stipulated that we had to upgrade our new entrance to conform with commercial (as opposed to residential) standards. The key point was that they wanted us to widen the main berm where the new entrace crosses the seasonal creek bed. It's currently ten feet wide at its top, and the county wants twenty feet so that cars can pass side by side.
clearing the space for widening the road bed
Now, come the middle of May, the ground is just right for the next step. When our soil is too wet, it sticks in the bucket of the backhoe resulting in having to shake the bucket in a manner reminescent of a cat with a bit of Scotch tape stuck to its paw. Wet soil is difficult to pack down because it tends to squish out from under pressure instead of becoming compact.
When our clayish soil is too dry, like it will be in August, it's difficult to dig because the clay and rock mix makes for a remarkable immitation of concrete. In addition, the dry clay tends to resist compacting, so that's not good either. Having worked with our soil for many years now, we've become sensitive to the right time to do any given job. And right now is the perfect time to work on creating the base for the section of the new entrance that needs to be widened.
Widening the berm will require a lot of fill dirt, and the farther we have to haul it, the more expensive the job. And so we decided to increase the size of our parking area at the Landing, and use the dirt removed for fill. That way, we get a double benefit for each cubic yard of dirt relocated.
the trackhoe starts digging at the Landing
When digging down in most parts of Windward, one finds a few feet of dirt and rocks before encountering a fractured basalt layer that makes it difficult for rain water to penetrate deeply or quickly. As a result, our soil can be very plastic when saturated, and very hard when it dries out. The shallowness of the water-retaining zone is one of the perameters we have to factor in when planting, and a key reason for the work done in terracing the garden areas.
Lindsay and Andrew set out flags to guide the excavation
The area around the Landing is different in that it's an area where spines of virgin basalt rise to the surface. Back twenty years ago when we first ran our waterlines, it took us three weeks of afternoon work sessions to create an eighteen inch deep passage through one of those spines so that we could get the water line deep enough to ensure that it wouldn't be subject to freezing.
a rocky spine that rises to the surface
Back then all we had were sledge hammers and cold chisels to work with. George's huge trackhoe was able to make some headway with the side of the basalt spine, but even then the work was difficult enough that one of the hardened teeth snapped off the bucket and had to be welded back on. That was a good example of the need to not only have the tools to do the job, but also the tools needed to maintain the tools.
welding a tooth back onto the bucket
We knew from previous digging that the area we were wanting to flatten out was bounded by rocky spines to the east and the west. We knew where the eastern-most spine was because it broached the surface (as shown above), and the trackhoe did its best to push the leveled area as far in that direction as it could.
virgin basalt (the grey rock)
reaching almost to the surface
Fortunately, in between the two spines, the excavation wasn't as demanding, and for most of the day there was a steady stream of dumptruck loads of fill heading down to the new entrance.
dumping the first load of fill dirt
Then George used his bulldozer to smooth the fill out and take advantage of the weight of the bulldozer to get an start on compacting the fill. It was delightful to see that we'd gauged the moisture content of the soil just right.
the bull dozer starts spreading out the fill
With the fill smoothed out, the weight of next load of fill was used to compact the last load of fill dirt. Loaded with twelve cubic yards of fill, the dump truck weighed around 25 tons so as it backed over the newly placed fill, it did an excellent job of compacting the new roadbed thereby ensuring many years of good service as a roadway for passenger cars.
the dump truck using its loaded weight to compact the road bed
When the dump truck reached the point where the last load of fill had run out, it would dump its current load and the process would repeat until by the end of the day, more than two hundred cubic yards of fill dirt had been relocated.
dump the load, return to the Landing
for another, and repeat
Meanwhile, I was keeping an eye on how the digging was progressing, hoping to ensure that the flat area created could become a useful storage area. One of the tools that's helpful in doing that is a sighting level. It's a short telescope that uses a mirror to reference a bubble-level. When the bubble is matched up with the internal center line, your sight line is level.
using a sight level to monitor the depth of the excavation
Using a sight level involves having someone hold a measuring stick at the other end. By sighting to the stick, and then comparing the measurements, the difference indicates how deep the excavation is.
using a measuring stick to determine the excavated depth
Eventually, more than 240 cubic yards of fill had been moved, and the new berm had reached to the point where any more fill would have started to cover up the area where we'll need to install more culvert to contain the creek as it passes under the berm. Right now the creek is still flowing, so that step will have to wait for the dry season. For safety's sake, we left the last load as a mound to block off that portion of the new entrance.
temporarily blocking off the newly widened road bed
I started to write, "When the work was done and the dust had settled ..." but that traditional turn of phrase wouldn't be accurate since by timing the work just right, a lot of dirt was dug up and moved without generating any dust to speak of. What the day's work did create was a major step forward toward commercializing the new entrance, and a very nice addition to our vehicle parking area at the Landing.
our relatively tiny 5-yard dump truck
provides some scale