8′ Commercial GeoPool
Once the upgrades from Prototype 4 were proven to work, we redesigned the Geo-Pool frames to be stronger and lighter using the heavier square tubing material. This also made the pools vastly more portable. To increase capacity, without increasing the pools’ foot print, we increased the height to 8 feet.
To test the frames for strength, a standard 10 foot section was erected and wet sand was piled against it. To be sure the frame loading would be able to take the stress, we then drove a large pay-loader up the sand-covered frame and parked it. No damage was done to the frame as a result of the test.
The frame-to-frame connection was redesigned to lock the frames together while allowing them to flex. With the upgraded connectors, there should never be a failure issue.
While the frames are overdesigned from a structural basis, they function as well as, or better than, the earlier versions. They have the strength to stand up to glancing blows by an excavator.
The drive over clean out gates have been the best upgrade we have made since the dump doors. The gates make access into the Geo-pool more efficient allowing for the pool to be cleaned out much faster.
The test site for the eight foot Geo-Pool was a water reservoir having a capacity of 8.0 million gallons. The reservoir had silted in over the course of the last 75 years with top soil, silt, and animal waste. Despite filtering extremely high organics (10%+), no polymers were needed. Over 20,000 yards of material was processed during this demonstration.
We experimented with clean out gate and dump door placement, taking advantage of certain characteristics of the work site. We determined that proper placement of the doors and inflow are critical for proper functioning of the pool.
We also determined that, when dealing with extremely high organics, placement of the discharge pipe is important. Failure to properly place it will result in wet spots or areas of lighter materials that fail to dry in a timely manner.
Because of the high levels of organics and magnesium, plus alkali, the material was thixotropic. Instead of being able to open up the pool within 4 days of going into dry-down, it will take an extra week or so to dry down the fines blocking access to areas that are properly dried down.
We found that, in this last case, we were able to walk on portions of the pool within a day of beginning dry-down. However, because of the less than optimal placement of the discharge pipe, we were unable to begin digging out for some time.
Another thing that we discovered was that proper loading helps the drying process. Because the dredge and pool were more efficient than we had anticipated, we began to run out of water. The water level dropped enough that, despite 11 inches of rain over the course of the pump cycle, it began to impede our progress and imperiled our ability to remove the dredge from the pond.
One item that would improve the speed and efficiency of dig out would be a large gravel conveyor. This would allow the spoil to be removed from the pool immediately while allowing the excavators to continuously dig new areas.
As specified above, placement of the intake pipe is as critical as the dump door placement.
The discharge pipe needs to be over the clean out gate or right next to it. This allows the heaviest material to accumulate right at the clean out gates, thus speeding up the beginning of the dig-out. In addition, optimal discharge pipe placement allows the fines and light materials to collect at the lowest point of the pool. This makes for a deeper layer, which helps to squeeze the water out of the lighter materials. The dump doors need to be placed opposite the intake pipe, or where you think the best path of the bulk water to return to the water source.