What is CU in soils?
What is CU in soils?
The uniformity coefficient (Cu) is defined as the ratio of D60 to D10. A value of Cu greater than 4 to 6 classifies the soil as well graded. When Cu is less than 4, it is classified as poorly graded or uniformly graded soil. Uniformly graded soil has identical particles with Cu value approximately equal to 1.
What is Structural soil used for?
Structural Soil is a medium that can be compacted to pavement design and installation requirements while permitting root growth.
How do you make structural soil for roads?
The soil needed to make structural soil should be loam to clay loam containing at least 20% clay to maximize water and nutrient holding capacity. The proportion of soil to stone is approximately 80% stone to 20% soil by dry weight, with a small amount of hydrogel aiding in the uniform blending of the two materials.
How much structural soil does a tree need?
Using the ‘rule of thumb,’ an estimate can be calculated that a tree with a 20 foot crown diameter needs approximately 600 cubic feet of soil to support it. Assuming a useable rooting depth of 3 feet, one way of dimensioning the space needed for this tree would be 20′ x 10′ x 3′, or 600 cubic feet.
What is uniformity coefficient of soil?
uniformity coefficient (u-ni-form’-i-ty). A numerical expression of the variety in particle sizes in mixed natural soils, defined as the ratio of the sieve size through which 60% (by weight) of the material passes to the sieve size that allows 10% of the material to pass.
What is uniformity coefficient of sand?
The uniformity coefficient describes how similar in size the sand particles are. The silt content is the percentage of sand with a diameter < 0.1 mm. If the uniformity coefficient is below 1.5, that means that all of the sand particles are very similar in size.
What are silva cells?
The Silva Cell is a modular suspended pavement system that uses soil volumes to support large tree growth and provide powerful on-site stormwater management through absorption, evapotranspiration, and interception.
What is CU in the expression Cu D60 D10 where D60 and D10 are the sizes of particle such that 60% and 10% of the particles are finer than these sizes respectively?
Cu – Uniformity coefficient. Cu = D60/D10. Cc – Coefficient of curvature.
What is uniformity coefficient and what is its significance?
How do you find CU and CC?
Cu – Uniformity coefficient. Cu = D60/D10. Cc – Coefficient of curvature. Cc = (D30)^2 /(D60)(D10).
How much do Silva cells cost?
According to bid tabulations from projects across North America, Silva Cell projects generally cost from $14 – $18 per cubic foot installed (that estimate includes everything except the base course, the final paving and the tree itself).
What are tree cells?
The vascular cambium lies just inside the phloem cells. It produces phloem cells on its outside face, and xylem cells on its inside surface. Xylem cells are elongated cells specialized for transport of water and dissolved ions throughout the tree.
What is CU Structural soil made of?
CU-Structural Soil™ utilizes Gelscape® hydrogel as a non-toxic, non-phytotoxic tackifier, in addition to stone and soil components. CU-Structural Soil™ is intended for paved sites to provide adequate soil volumes for tree roots under pavements (Fig. 1.9).
How much can CU-Structural soil hold the 100-year storm?
Twenty-four inches (24″) of CU-Structural Soil can hold the 100-year storm in Ithaca, NY, of 6” of rain in 24 hours. For more information on the research and use of CU-Structural Soil go to:
What is the infiltration rate of Cucu-structural soil?
CU-Structural Soil has a rapid infiltration rate (>24” per hour) and has 26% porosity after it has been compacted to 100% peak density. Ordinary loam soil compacted to 100% peak density has an infiltration rate of 0.5”/hour.
What is the cost of a CU-Structural Soil project?
Samples from the licensed producers are tested at an independent soils lab for compliance. Over 1700 CU-Structural Soil projects have been installed successfully all over the US, Canada, and Puerto Rico during the past 15 years. Costs range from $40-$75 per cubic yard.
