As Installation Coordinator, a big part of my job at DeepRoot is working with contractors to help make sure that they are comfortable installing the Silva Cell and to act as a technical resource when needed. Many contractors have questions about productivity during Silva Cell installations, which is what I want to talk about today.
Let me start by saying that any discussion of productivity and productivity rates is challenging because of the number of variables involved. Factors such as the length, width, depth (number of layers), access, working room, size of equipment, motivation of the workers, etc. will all effect the productivity rate that is ultimately achieved.
With that said, here is some general information that will help guide conversations about productivity when installing the Cells.
Assuming the excavation has already been done and the aggregate sub base prepared, a four man crew (3 laborers and 1 operator) should be able to complete an installation of 100 to 150 Silva Cell frames in an 8 hour day. “Complete” here means installing the frames and the geogrid, filling the frames with soil, backfilling around the outside and attaching the decks.
The two most time-consuming tasks during the installation process are excavating the Silva Cell area and then filling the frames with soil and backfilling around them. Laying out the frames, stacking the layers, attaching the geogrid and installing the decks takes very little time in comparison.
Here are two photos from of a project where the crew completed the installation of 90 frames in a day (10 frames x 3 layers x 3 trees):
*Surface area = approximately 9.3 sq meters x 3 = 27.9 sq meters.
*Volume = 9.3 sq meters x 1.219 meters (3 layers x 16 inches/layer) x 3 = 34.0 cu meters
Here is an example of a larger site and larger equipment, where the crew completed an average of 204 frames in a day (34 frames x 3 layers x 2 trees):
*Surface area = approximately 29.3 sq meters x 2 = 58.6 sq meters.
*Volume = 29.3 sq meters x 1.219 meters x 2 = 71.4 sq meters
(Calculation includes 1.5 inch/.0381 m space between frames and the 4 ft x 4 ft/1.22 m x1.22 m tree opening.)
As with any type of construction, there are too many factors to offer any type of guarantee for installation times, but hopefully these examples will give you some idea of what to expect on your projects. Please feel free to contact me (firstname.lastname@example.org) with any questions or to discuss the specifics of your project.