The movement of water through the soil surface, known as infiltration, is a fundamental hydrologic process. It governs the partitioning of rainfall into surface runoff and subsurface storage, influencing everything from flood forecasting and irrigation efficiency to the design of stormwater management systems and landfill liners. Accurate quantification of the infiltration rate is essential for civil engineers, hydrologists, and environmental scientists.
Geotextiles are used in a wide array of applications, from road construction and coastal protection to landfill engineering and hydraulic structures. Their primary function is to improve the stability and performance of soil structures by providing filtration, separation, reinforcement, and protection. Given their critical role, it's essential to understand and accurately predict their behavior under various conditions, including hydraulic flow and soil interaction.
The testing area should be nearly level. If you want to test the infiltration rate of subsoils rather than the surface layer, you must carefully excavate a pit to the desired depth, ensuring minimal disturbance to the exposed soil.
Open metal cylinders, usually constructed from steel or aluminum, with a sharpened bottom edge to ease soil penetration.
The test is crucial because it helps distinguish between (how fast water moves through saturated soil) and infiltration rate (how fast water enters the soil surface). 2. Importance and Application astm d338518 pdf
: Managing irrigation requirements, leaching thresholds, and field drainage efficiencies. 2. Soil Suitability and Limitations
Acts as a hydraulic barrier. The water infiltrating from the outer ring saturates the surrounding soil, forcing the water in the inner ring to flow strictly downward in a vertical direction.
The standard outlines the following test methods:
Designing retention basins, bioswales, and permeable pavements requires accurate soil infiltration profiles to prevent flooding and meet municipal drainage regulations. The movement of water through the soil surface,
Forces the water within it to flow strictly vertically. Measurements are taken exclusively from the inner ring to isolate the true, one-dimensional vertical infiltration rate. Technical Specifications and Equipment
When water is poured into a single ring driven into the ground, it tends to lateralize—diverging sideways as it moves downward due to capillary action and gravity. This lateral flow artificially inflates the measured infiltration rate. The double-ring infiltrometer solves this issue:
= Volume of water added to the inner ring during the time interval ( cm3cm cubed = Cross-sectional surface area of the inner ring ( cm2cm squared = The time duration of the specific measurement interval ( Plotting the Curve
To execute an ASTM D3385-18 compliant test, you will need a well-equipped field kit. The core apparatus components include: 1. The Rings Geotextiles are used in a wide array of
The standard provides a rigorous procedure for the field measurement of soil infiltration rates using a double-ring infiltrometer. This method is essential for civil engineering and environmental projects, including the design of septic tank fields, irrigation systems, and stormwater management facilities. Understanding ASTM D3385-18
The ASTM D3385-18 Standard Test Method quantifies the over a given timeframe. This index value is called the incremental infiltration velocity, usually calculated and reported in centimeters per hour (cm/h) or inches per hour (in/h). Scope and Limitations
Because water viscosity changes with temperature, ASTM D3385-18 recommends correcting the final steady-state infiltration rate to a standard temperature of 20°C (68°F) using viscosity correction factors provided within the official standard tables. Primary Applications of ASTM D3385-18