Originally we intended to backfill only once, about half way through and then at the end when we bury the structure. But, the structure is going to be a bit higher then expected and working higher up becomes trickier, especially for two people … so … after finishing level 16 we decided to backfill again.
Work started yesterday when we pulled up the plastic cover and scanned it for tears and wholes. Most of it was in good shape (it got buried in some soil which protected it from the sun). We replaces one section that was torn and brittle.
Florin arrived at 10am and started by clearing a path (we cleared most of it by peeling away soil as we filled the tubes):
He brought soil into the tight corner with the front loader then used the spoon to move / push it into a place:
Then he came around the top of the site and started filling behind the structure
And with a bit of manual labor we the first corner was full
And moving gradually along the wall … until is was all full
… bringing us to the other side which had better access so that the front loader could be used to bring soil in
then we went back around to the first corner (which we left slightly exposed in case we needed to bring in more soil) … and buried it:
… it was done in 3 hours … and now again we get to work at “ground level” … this time all the way to the top:
It is amazing to see how quickly wild grasses and weeds went to work healing the soil around the site … and now, after the excavator, how bare everything looks again … we are already looking forward to bringing in plants to heal the site and help nature take over once again.
We tend give much attention to the growing walls, but we would like to acknowledge the unsung heroes of this project … the cans we toss up the walls to move soil from wheelbarrows into the sacks and tubes. We recently retired the first pair of cans … and here you can see side be side a new can next to a can that has moved ~25 cubic meters of soil (one can at a time!).
My sister, Orit came to visit for a few days and joined us for a few sessions … we now regularly sit on the walls to take in the sunset (horizon rising):
Istvan also visited with us briefly, showed us saturn in his telescope and joined us for a work session:
Liviu and Ana also visited with us and Liviu also joined us for a morning session (we forgot to take a picture … so you’ll have to take my word for it) … and we have finished levels 14 and 15, we are now working on 16 and the arches have started to form:
The arches have started to draw a finish line … the walls will be finished when the arches are complete and one additional level has been layed on top. Right now, my estimate is that 21 levels should get us there … but that will become more clear as we start to move up through the next layers.
We are currently inquiring about two options for a roof … more on that in an upcoming post.
We had one weekend of construction at the beginning of June with the help of Adi and Dan … we got 10 and half of 11 done.
We then paused because of my allergy-period and because we were busy finishing and launching the new Cutia Taranului website. In recent weeks we got back in the saddle, we finished 11 and 12 … and its feeling more and more like a place.
We’ve also put in velcros to which we plan to attach a grain storage and dispenser (planned to hold ~100kg of grains):
Sia, a new puppy who has been with us for a few weeks is getting acquainted with the site … and also has manifested a destructive quality … it seems she enjoyes tearing into earthbags and digging soil out 🙁
Today we started 13 which brought us to the levels of the rectangular door frames …. which means that soon we begin to form the arches on top of the doors.
And finally we have out overall progress indicator. This pile of soil is like an hour-glass … if my calculations were correct it should have enough soil to bring us to completion. When we started construction this year the pile reached out to where the mixer is currently standing so we’ve taken quite a bite out of it. It is nice to feel the space starting to open up and reconnect with the world beyond it.
I estimate we are going to end up with 19 or 20 levels.
And lastly some number I’ve collected:
- We are currently mixing batches with a ration of 4 shovels of sand + 12 shovels of clay soil. This fills an 80 liter wheelbarrow.
- A wheelbarrow is roughly the amount of soil that goes into a sack (1 meter long when flat, 80cm when filled to the max) … though we are using mostly tubes (not sacks).
- Each batch includes 2 wheelbarrows.
- Each wheelbarrow contains ~25 cans (3 liters in a can) … so it takes ~25 tosses to “move” a wheelbarrow of soil up the wall.
- Each batch (of 2 wheelbarrows) translates into ~1.5 linear meters of wall (we are using 50cm wide – when flat – tubes and bags).
- Which means that each can holds about 3 linear centimeters of wall.
- At the current rate Iulia and I (neither of us particularly strong) are doing ~2 linear meters of wall an hour (though we will slow down as we move higher up the wall).
- At this rate we can do a level in 3 or 4 days (we work at most 6 hours a day in two sessions … morning and evening).
We’ve completed levels 8 and 9 …
… on level 9 we were joined by Itsik and Yifat who visited with us for a week … so we reached and celebrated the end of 9 together.
In level 9 we also put in additional vertical reinforcement by pounding in rebars into the longest stretch of buried wall that we have (~6 meters) … and we will continue to do that in an interlaced pattern to give the wall some more strength to resist the weight of the earth piling up behind it.
Which brings us to today … soil … we called the excavator back (marking what is probably the half-way point of wall construction) … to start backfilling and bringing some more soil to our mixing station (so that I don’t need to carry it in a wheelbarrow). Yesterday we prepared by pulling the plastic covering over the walls
.. and so it started … and very quickly the corner behind the first retaining wall was filled up ….
… then the side and rear corner
… during the backfilling, a new soil pile near the mixing station started to appear
… and before you know it (almost three hours later) the backfilling was complete …. so from the outside we are back at ground level (which does make some maneuvering on the walls easier)
… and a huge pile of soil (30+ cubic meters) is now blocking the entrance and hiding the site … when that soil is gone, construction of the walls should be complete (or very close to completion)
As the work progressed we realized we were going through A LOT (= surprising amount) of soil … we’ve used up most of the free soil on and around the site … and it doesn’t look like what we have left will be enogh to complete backfilling and covering the structure. At first this felt like a potential problem … but it quickly transformed into opportunity. It looks like the supply of soil needed to complete this project will overlap and lead into the next project. One option weve been discussing is a small lake (a whole other story). Another option is to start excavating what may be the next construction project … either way … it left us with a pleasant sense of continuity 🙂
Good Earth Nepal has published this PDF on its site.
Before presenting some highlights I would add that there are a few details which, to my understanding are only correct in the context of typical above ground houses, less so with bermed or underground structures.
“At present, there are over 15,000 Earthbag buildings worldwide with recent Earthbag constructions gaining approval under strict US building codes.
An estimated 55 Earthbag structures built in Nepal survived the 2015 earthquake, in regions ranging from Solokumbu to Sindhupalchok to Kathmandu.
… The main material of an Earthbag structure is ordinary soil obtainable at the worksite.
… A study by the U.S. Federal Highway Administration found that the half -life of polypropylene fabrics in benign environments can be 500 years or more. The
bags themselves have a tensile strength even higher than that of steel, and can resist circumferential forces generated from the weight above.
… An Earthbag building uses its own weight to anchor itself to the rubble trench foundation. Since the superstructure is not attached to the foundation by bolts or rebars, the foundation and the
superstructure are able to move independently minimizing the shock transfer to the walls. A rubble trench is also built of individual units rather than a continuous beam further absorbing the shock.
Earthbags are resilient. As per an experimental study on vibration reduction … Earthbags have a relatively high damping ratio with horizontal as well as well as vertical vibrations effectively reduced.
… All of these components make Earthbag structures extremely earthquake-resistant. Tests done in accordance with IBC standards have found that Earthbag construction far exceeds Zone 4 standards, devised to protect against the very highest level of seismic activity. Numerous Earthbag structures have been built in the United States. Earthbag structures are permitted by the California Building Code, the toughest in the United States due to high seismic activity.”
After finishing level 6 we ordered another batch of sand (another 6 cubic meters, like the first batch).
… and it was delivered just as we were getting started on Level 7 (because of tricky vehicle access to our property it came in two batches of 3 cubic meters) … this is the second batch being delivered with the first one in place:
Layer 7 was relatively smooth sailing … that is with uninterrupted and continuous bag laying … also the overall wall length is shortening as both of the retaining walls are starting to shorten:
This weekend I was alone and so could not progress with construction so I focused on preparing soil for the next two layers (I hope):
We’ve pretty much used up the entire side-hill that was created during excavation. I pulled down 45 roughly sifted wheelbarrows of soil. You can see the soil pile that I’ve prepared behind the sand pile. That should allow us to make good progress with mixing and packing the next two layers. Its a tough job … and I hope I’ve seen the end of it .. at least for a while. After the next two layers we want to bring in the excavator to do some backfilling and to collect a large pile of soil next to the sand-pile … that should take us nearly to the end of the earthbag phase of this project
We’ve had a fairly long stretch of work without rain interruption … but that is about to change. I’ve pulled the plastic that will cover the walls, over the walls … and later today will go out and layout more tarps to keep the site as dry as possible.
Level 5 was already finished yesterday … but today required a bit more preparations before starting level 6.
The central preparation was putting in the plastic moisture barrier around the entire external perimeter of the wall. We spread it out, folded the corner down and covered it with soil to hold it in place … while doing that we also starting a bit more backfilling to cover the earth-tubes. Thebackfilling gave me a sense that the structure is physicall connecting with the place. Also we got a taste of wha tbackfilling would be like … and we look forward to bringing the excavator back 🙂
Level 5 is also where we put in the 3 velcros to which we will attach electric sockets:
Some pictures of level 5 … with a glimpse of Rodica, a first volunteer to visit Bhudeva.
… and all preparations done and ready to go with level 6 … Vasile mounted on Maria with a tube ready to be filled:
… and this final image is dedicated to my father 🙂