Humboldt HS-4210 Digital Static Cone Penetrometer - Manual (Page 2)

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. Typically it is used
to assess material properties to a depth of 762 mm (30 inches) below the
surface. With extensions the DSCP can be advanced to greater depths.
B) The operator pushes the DSCP into soil by applying weight to the handles.
This is designed to handle applied loads up to 250 lb. Loads higher than
this will result in an “overload” reading on display. The penetration rate
should be consistent and no eratic loads should be applied vertically or
horizontally as this will result in unreliable information and could result
in bending of the rod. Through continued use of this tool, correlation
charts may be developed on local material to correlate to blow counts,
unconfined, in situ CBR and other measurements.
C) The Humboldt DSCP can be used to estimate the strength characteristics
of fine and grained soils used for construction materials and weak stabilized
or modified materials. This may be used to classify cohesive soils in terms of
consistency, determining the approximate unconfined compressive strength
and the evaluation of shear strength using the penetration principle. These
readings do not replace laboratory tests but may be used to obtain needed
field data. The Humboldt DSCP should not be used in highly stabilized or
cemented materials or for granular materials.
D) The Humboldt DSCP can be used to estimate the strength of in situ
materials underlying a bound or highly stabilized layer by first drilling or
coring an access hole.
NOTE: The DSCP may be used to assess the density of a fairly uniform material by
relating to penetration rate on the same material. In this way under compacted or ”soft
spots“ can be identified, even though the DSCP does not measure density directly.
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