Evaluating Performance of a Chilled Mirror Device for Soil Total Suction Measurements

Soil suction is one of the stress state variables describing the behavior of unsaturated soils. Soil suction has found its applications in all branches of the unsaturated soil practice, from volume change predictions of expansive soils to slope stability problems. There are different methods to measure the total suction in a soil. Chilled mirror dew point technique is one of the methods to measure the total suction. The WP4 device utilizes the chilled mirror dew point method and measures the suction by determining the relative humidity of the air above a soil sample. This study investigates the capability of the particular WP4 device by developing a characteristic curve. The characteristic curve is developed by measuring the osmotic suctions of salt solutions of NaCl and KCl at different concentrations covering a wide range of suction. The results show that the device is good only in measuring suctions more than 4 pF as the measured values at lower suctions is always a constant value (1.79 pF). A comparison study is also conducted on soil samples using the filter paper method and WP4 device. The results of the WP4 and filter paper method are in good agreement at high suctions. Because the proposed one-point calibration check by the manufacturer might not be sufficient, there is a need to develop a unique characteristic curve for each device.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: pp 56-64
  • Monograph Title: Advances in Transportation Geotechnics and Materials for Sustainable Infrastructure

Subject/Index Terms

Filing Info

  • Accession Number: 01536493
  • Record Type: Publication
  • ISBN: 9780784478509
  • Files: TRIS, ASCE
  • Created Date: Sep 2 2014 9:06AM