Geneq > Essais sur matériaux > Érodabilité
Appareil de mesure de d'érodabilité
Modèle HM-4000


The HM-4000 Erosion Function Apparatus (EFA) was designed and built to measure the erodibility of soils and soft rocks. Applications include piping of dams, beach erosion, and surface erosion problems. In the case of scour at bridges, the EFA leads to improved accuracy on scour depth predictions. This effective new apparatus offers several advantages over previous tests methods.

Advantages
  • Minimum sample disturbance
  • Measurement of erosion rate vs. shear stress
  • Measurement of critical shear stress
  • Incorporation of the test results in a scour prediction method SRICOS
 Test observation window
The HM-4000 Erosion Function Apparatus helps prevent bridge failures by measuring soil erodibility. Used in conjunction with the new SRICOS scour prediction method, the HM-4000 can provide more accurate erodibility measurements and scour predictions.

Specifications
Flow Rate 0-8 meters per second
Specimen Size Accepts 3.0" OD x 2.875" ID (76.2 x 73 mm) Shelby tubes
Dimensions (WxDxH) 96" x 40" x 96" (2,438 x 1,016 x 2438 mm) (excluding wheels and PC)
Supplied complete with PC, SRICOS Analysis Software and Flow/Temperature Sensors

Sricos method
The New SRICOS Method improves the accuracy of Pier Scour Predictions.
The HM-4000 EFA is designed for use in conjunction with the new SRICOS Method of scour prediction. In comparison with the HEC-18 equation (a standard for calculating scour predictions), SRICOS generally led to smaller calculated scour depths and compared more favorably to measured scour
depths than HEC-18. The EFA uses either of two variants of the SRICOS method:

The Extended SRICOS Method
  • Calculate the maximum depth of scour
  • Collect soil samples at the site
  • Test samples in the EFA to obtain the erosion rate vs. the hydraulic shear stress applied
  • Prepare the velocity hydrograph for the bridge
  • Use the SRICOS program with 3 & 4 above as input and generate the depth of scour vs. time over the period covered by the chosen hydrograph

The Simple SRICOS Method

  • Calculate the maximum depth of scour
  • Collect soil samples at the site
  • Test samples in the EFA to obtain the erosion rate vs. hydraulic shear stress applied
  • Calculate the equivalent time for a given design life of the bridge and for the design velocity
  • Using known equations, calculate the scour depth at the end of the design life

Cat.No. Description
HM-4000 Erosion Function Apparatus
Supplied complete with PC, SRICOS Analysis Software and Flow/Temperature Sensors.