Overview
ISO 10772:2012 - Geotextiles - Test method for the determination of the filtration behaviour of geotextiles under turbulent water flow conditions - specifies a laboratory test to assess how much soil passes through a geotextile when exposed to turbulent water flow (e.g., wave action, ship passage). The method produces quantitative soil passing results that help evaluate the filtration stability of geotextile filters for erosion protection and hydraulic engineering applications.
Key Topics and Requirements
- Purpose: Measure soil passing through a geotextile under simulated turbulent conditions to determine mechanical filtration stability.
- Specimens & sampling: Three circular specimens punched from a laboratory sample (diameter 168 mm); sampling per ISO 9862.
- Test soil preparation: Soil dried to constant mass at 105 °C; example grading curve for medium–coarse silt provided in Annex A. Undrained cohesion ≤ 1,5 kN/m² for the example test soil.
- Sample assembly: 1 500 g test soil placed on the geotextile, compacted using a 151 mm brass disc and vibration (50 Hz, 1.5 mm amplitude for 240 s); specimens saturated in tap water at 20 °C ± 5 °C for ≥ 16 h.
- Apparatus: Three-sample test rig with turbulence-producing four-bladed propeller (260 rpm) producing flow velocities ~70–90 cm/s and pressure pulsations ~17.3 Hz; water depth ~20 cm. Required ancillary equipment includes oven (105 °C), electronic balance (0.01 g), hydrophilic cellulose filters (5–13 µm), and collection vessels (>60 L).
- Procedure: Five loading phases of 30 min each (total 150 min). After each phase, collect effluent, filter, dry (105 °C ± 5 °C) and weigh soil passing.
- Evaluation & criteria: Calculate mean and standard deviation for three specimens; plot cumulative soil passing (soil passing value Spv). For the Annex A test soil, stability guidance: soil passing in last phase should not exceed 30 g and total passing not exceed 300 g. Report water temperature, soil properties (plasticity, cohesion, grading), and any deviations.
Applications
- Design and verification of geotextile filters in:
- Coastal and riverbank erosion protection
- Breakwaters, revetments and seabed protection
- Ports, harbours and maritime infrastructure subject to waves or vessel-induced turbulence
- Laboratory performance testing for product development, QA/QC, and contract specification compliance.
Who would use this standard
- Geotechnical and geosynthetic engineers
- Construction contractors and coastal engineers
- Test laboratories and QA/QC managers
- Geotextile manufacturers and product developers
- Regulators and project owners specifying filtration performance
Related standards
- ISO 9862 - Sampling and preparation of test specimens
- ISO 12956 - Characteristic opening size (used for oscillating device reference)
- Additional referenced methods: ISO 10320, ISO 11465, ISO/TS 17892 series for soil testing and characterization
Keywords: ISO 10772:2012, geotextiles, filtration behaviour, turbulent water flow, soil passing, filtration stability, hydraulic engineering, erosion protection.