The project for an engineered design of our Dupont Tree Plaza got under way Nov 30. Here you see John, of Soils, Inc, making two holes in the ground at the west end of the plaza location.
Why test the soil here? Below this site we plan a "reservoir" filled with soil to grow trees. The reservoir will run under most of Plaza, and be shaped to direct water to the city's combined system (CSS) of drains. Any remaining water under there must be absorbed by native soil. So how does it behave?
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| John at west end of site by Colonial Parking, |
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| John measured the water going in the hole, and the time. |
| How fast does this soil absorb water? This determines key aspects of the project and details of the design. | | So John bored 7 feet down, pulling up sections of the core bit
by bit. He laid them out on the ground. He kept and labeled samples for
lab analysis. | | | | | | |  |
| Here John shows how the deeper soil is different; it has more clay, as you can see by the color. |
He capped the bore tubes so rain water (or trash) could not get in there. He returned later, to measure how much water in the hole was absorbed in the interval. This will give us the INFILTRATION RATE of this particular soil.
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| John of Soils Inc and Rebecca Stack of Designgreen LLC cheer the kickoff. |
For more on the draft site plan and the design contract award see our post of October 26.
We thank the Chesapeake Bay Trust for funding to make an Engineered Design of the Dupont Tree Plaza. For this project's background and scope please visit our
Plaza project page.
