The Vision
Cone Penetrometer
(VisCPT) 
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Read about the VisCPT below or visit our newest sites (April, 2000): 

VisCPT video clips of soil liquefaction

 

VisCPT log from Treasure Island

 

Still images from Treasure Island


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The Vision Cone Penetrometer (VisCPT) was developed at the University of Michigan in 1995/96.

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By adapting miniature video cameras to the electronic cone penetrometer, the VisCPT has overcome the major previous shortcoming of the Cone Penetration Test (CPT). Namely, the inability to visually observe the soil.

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Click on Dr. Raschke to see the VisCPT viscpt1t.jpg (5494 bytes)

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TheVisCPT consists of two cameras, lenses and lighting systems with individual housing units. The two cameras record the soil images through synthetic sapphire windows.

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Click to see the camera assemblies   viscpt4t.jpg (7167 bytes)

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    viscpt2t.jpg (7330 bytes)  Click to see the illuminated sapphire window

rclip7.jpg (21845 bytes) Each camera system operates at a different level of magnification thus providing fields of view between 2 mm and 20 mm (diagonal).
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The images are recorded continuously in real time as the probe is advanced at the standard CPT rate of 2 cm/sec.

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The sequence of  VisCPT images shown at left reveals soil grain sizes ranging from medium sand near the top to silty fine sand at the bottom.

  
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   Horizontal field of view       =     1.0  cm  
   Total vertical length            =   14.2  cm

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A field-portable S-VHS recording system and monitors allow for immediate field inspection as well as recording for later viewing.

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Click for the recording system viscpt3t.jpg (4256 bytes)

rclip13.jpg (21810 bytes) After recording, the continuous stream of images is digitized.  Computer vision image-texture techniques analyze the data for soil grain size.
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coming soon:

Links to Ali Ghalib's image analysis techniques and Seung Cheol Shin's neural networks

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In summary, the VisCPT offers the following advantages to geotechnical and geoenvironmental site characterization:

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Visual inspection of soil without sampling, a particularly attractive feature for geoenvironmental applications.

A permanent visual record of the soil is collected, eliminating the need for sample storage.

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Ambiguous CPT data may be resolved. Exact elevations of stratigraphic transitions are revealed.

Continuous recording of the soil stratigraphic column at very high resolution. Anomalous clay lenses, fissures and sand seams, even as thin as 0.5 cm. are detected.

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Images are digitized and computer vision techniques are used for image-texture analysis of the soil.

Grain size distributions can be inferred from the textural analyses.

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Suggested Reading:

Hryciw, R.D., Ghalib, A. M. and Raschke, S. A. (1998) "In-Situ Soil  Characterization by VisCPT", Proceedings of the First International Conference on Site Characterization (ISC'98), Balkema Press, pp.1081-1086.

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Raschke, S.A. and Hryciw, R. D. (1997) "Vision Cone Penetrometer (VisCPT) for Direct Subsurface Soil Observation", ASCE Journal of Geotechnical and Geoenvironmental Engineering, Vol. 123, No. 11, pp. 1074-1076.

Raschke, S.A., Hryciw, R.D. and Ghalib, A.M. (1997) "Adding Vision to the Cone Penetration Test", Proc. of the 6-th Great Lakes Conference on geotechnical and Geoenvironmental Engineering, Ann Arbor, MI pp. 37-50.

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Related Reading:

Ghalib, A.M., Hryciw, R.D. and Shin, S.-C. (1988) "Image Textural Analysis and Neural Network for the Characterization of Uniform Soil", accepted for publication and presentation at the 1998 ASCE Computing Congress.

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Hryciw, R.D., Ghalib, A.M. and Raschke, S.A. (1998) "Methods for Soil Characterization from Images of Grain Assemblies", Proceedings of the 2nd International Conference on Imaging Technologies: Techniques and Civil Engineering Applications", ASCE, pp. 88-99.

Hryciw, R.D., Raschke, S.A. and Ghalib, A.M. (1997) "Characterization of Particulate Assemblies Through Computer Vision", in Selected Research in Environmental Quality, Proc. of a Joint USAF/Army Contractor/Grantee Meeting, Jan. 14-17, Panama City, FL. , pp. 131-136.

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Hryciw, R.D. and Raschke, S.A. and (1996) "Development of Computer Vision technique for In-Situ Soil Characterization" in Emerging Technologies in Geotechnical Engineering, Transportation Research Record No. 1526, pp. 86-97.

Raschke, S.A. and Hryciw, R. D. (1997) "Soil Grain Size Distribution by Computer Vision" ASTM Geotechnical Testing Journal, Vol. 20, No. 4, pp. 433-422.


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For additional information contact the VisCPT Group:

  Prof. Roman D. Hryciw      Professor Scott A. Raschke
  University of Michigan       Lehigh University
  romanh@umich.edu                     sara@lehigh.edu

1998 Roman D. Hryciw