01.
Introduction This Manual covers the measurement of bearing capacity using the Humboldt Digital Static Cone Penetrometer (DSCP). Application A) This procedure is used to assess the in place strength of undisturbed soil and/or compacted materials. The bearing capacity can be used to estimate CBR (California Bearing Ratio), shear strength of strata, thickness of strata and bearing capacity. It may be used in horizontal or vertical construction applications, such as footings and shallow foundations.
Description A) The Humboldt DSCP in Figure 1 consists of a large easy to read display, Multiple selectable display units, padded handle grips, 30" dual rod design starter rod with available extensions and a standard 1.5 cm2 with an angle of 60°cone. B) Optional DSCP equipment can be found at www.humboldtmfg.com, including: • 30" Extension Rods • Replacement Cones 1.
Procedures A) Equipment Check 1) Before beginning a test, check to ensure the Drive Rod is straight by rolling the rod on a flat surface. Drive Rod may have been bent if overloaded vertically. 2) The Drive Cone Assembly must be checked to ensure proper movement and that the point is discernable. The point may eventually become rounded depending on the amount of use and types of material tested. The original diameter of the cone is 0.544".
Procedures (continued) C) Testing Sequence (continued) 3) Apply Force: The DSCP device is held in position, either vertically or horizontally. The operator applies consistent force to handles for cone to penetrates the material. Readings are monitored during penetration to obtain information related to soft spots, averages or peaks. Soil friction on the outside rod is not an influence in the reading.
Correlations (continued) Uniform Clay and Silty Clays Qc = 5 Qu Qc = 10 C Clayey Silts Qc = (10-20) Qu Qc = (20-40) C CBR = Value (%) Qc = (2.5-3.3) CBR Maintenance Testing with the Humboldt DSCP causes wear on the metal parts that make up the device. In order to ensure maximum service life, periodic inspections of the Humboldt DSCP for fatigue or damage are recommended.
Humboldt Mfg. Co. 875 Tollgate Road Elgin, Illinois 60123 U.S.A. Testing Equipment for U.S.A. Toll Free: 1.800.544.7220 Voice: 1.708.456.6300 Fax: 1.708.456.0137 Email: hmc@humboldtmfg.com Construction Materials HUMBOLDT www.humboldtmfg.
