log(f'c) = 0.081 + 1.309 log(CIV)
R2 = 0.90
Clegg Impact Value (log)
Figure 5. Clegg impact values plotted against compressive strength and show-
depth of 460 mm. Figures 6a and b illustrate the
where fc is unconfined compressive strength
use of the DCP equipment. The DCP consists of a
and CIV is the Clegg impact value.
steel rod with a cone attached to one end. This rod is
driven into the ground by a 8-kg sliding weight,
bearing ratio (CBR) (Yoder et al. 1991) using eq 2:
which is dropped 574 mm onto an anvil at the top of
CBR = CIV 2 0.07 .
the rod. The DCP is a dual-mass penetrometer, be-
cause the steel outer sleeve of the sliding weight
may be removed to produce a 4.6-kg weight for
Dual-mass dynamic cone penetrometer (DCP)
use in softer soils. In the case of the Raymark stabi-
The dual-mass dynamic cone penetrometer
lized waste, the 8-kg weight was used. The U.S.
(DCP) was used at two site locations (field test
Army Engineer Waterways Experiment Station
sections 1 and 3) at the Raymark site to deter-
established a database of field CBR values vs. DCP
mine the CBR of the stabilized waste material to a
index values of different soil types from various
sites (Webster et al. 1992). Figure 7 shows a plot of
Figure 6. DCP testing.