Bs En — Iso 22282-2 Pdf

BS EN ISO 22282-2:2012 – Geotechnical Investigation and Testing: Permeability Testing Using Open End and Packer Systems

2. Packer (Straddle) Tests

This is the preferred method for depth-specific permeability measurement. A packer system (either single or double) is used to seal off a discrete length of the borehole.

  • Single Packer: Seals the borehole below the test section.
  • Double (Straddle) Packer: Two packers isolate a specific interval between them.

Standard Procedure:

  • The borehole is drilled using water or mud.
  • Packers are inflated to seal against the borehole wall.
  • Water is injected into the isolated section at a constant pressure (constant head injection) or at constant flow rate.
  • Pressure and flow rate are monitored over time until stabilization.
  • Permeability (Lugeon value in rock or hydraulic conductivity in soil) is calculated.

Typical Applications: Layered soils, fractured rock masses, and determining the permeability of specific strata. bs en iso 22282-2 pdf

2. Safety and Risk Mitigation

Incorrect permeability data can lead to: BS EN ISO 22282-2:2012 – Geotechnical Investigation and

  • Underestimated groundwater inflow in excavations.
  • Failure of earth dams due to piping or seepage.
  • Unexpected settlement of structures.
  • Contaminant migration from landfill sites.

Scope of BS EN ISO 22282-2:2012

This standard specifies requirements for in-situ permeability tests applied to soils in three primary scenarios: Single Packer: Seals the borehole below the test section

  1. Saturated Soils: Tests using water as the permeant.
  2. Unsaturated Soils: Tests using air as the permeant (specialized applications).
  3. Test Methods: It details the performance of:
    • Constant head tests (for high permeability soils/gravels)
    • Falling head tests (for low to medium permeability soils/silts)
    • Variable head tests (for very fine soils)

Step-by-Step: How to Perform a Test per BS EN ISO 22282-2

While the PDF provides full details, here is a high-level summary of the procedure:

  1. Setup: Assemble the rigid-wall permeameter. Ensure it is clean and free of leaks.
  2. Sample Mounting: Place the soil sample (either undisturbed from a core barrel or remolded) into the permeameter cylinder.
  3. Saturation: De-air water and saturate the sample from the bottom up to remove trapped air.
  4. Test Selection:
    • For sands: Set up a constant head (inlet tank maintains a steady water level).
    • For silts: Set up a falling head (standpipe).
  5. Measurement: Record the volume of water flowing through the sample over a specific time (constant head) OR record the time for water to drop between two points (falling head).
  6. Calculation: Apply the appropriate formula from the standard to compute k.