Astm D338518 Pdf !link!

: Two concentric rings—usually a 12-inch (300 mm) inner ring and a 24-inch (600 mm) outer ring —driven into the soil to a specific depth.

Estimating seepage from canals, reservoirs, or retention ponds. 3. The Double-Ring Infiltrometer Apparatus

ASTM D3385-18 establishes a standard field method for measuring soil infiltration rates using double-ring infiltrometers to assess hydraulic conductivity. This procedure involves maintaining a constant water head in concentric rings, measuring vertical water flow to determine the infiltration rate [1]. You can access the full standard through the ASTM website . astm d338518 pdf

Engineers must carefully select a level test site. The rings are driven vertically into the soil using a driving plate and hammer to ensure a snug fit and prevent water leakage. In stiff or dry soils, a trench may be excavated to facilitate installation. Following installation, a constant or falling head of water is maintained in both rings.

Water used should be similar in temperature and quality to the liquid whose infiltration is being studied. : Two concentric rings—usually a 12-inch (300 mm)

The purpose of the outer ring is to promote one-dimensional, vertical flow beneath the inner ring. This design ensures that water infiltrates primarily in the vertical direction within the inner ring, where the actual measurement takes place, while the outer ring minimizes lateral spreading of water that would otherwise distort the results.

If you're tasked with or interested in writing a paper related to ASTM D3385-18, here are some steps to consider: Engineers must carefully select a level test site

Driving the rings can artificially compact fine-grained soils, leading to a lower measured infiltration rate than what naturally occurs.

When water infiltrates the ground, it tends to spread out laterally due to capillary forces and soil suction, not just downward via gravity. If you were to use a single ring, this lateral "edge effect" would lead to artificially high infiltration rate readings. By using two concentric rings:

To provide baseline empirical data for engineering designs requiring fluid containment or seepage. 2. The Science Behind the Double-Ring Infiltrometer