Figure 15-14.-Packing a chunk sample for transportation or
shipment to laboratory.
box and packing it, as shown in figure
15-14.
Cylinder Samples by CBR Mold
Figures 15-15 through 15-19 show a CBR
compaction mold,
fitted with a sampling
collar (or cutter), and how to obtain a cylinder
sample by using the CBR mold. This method may
be used in taking an undisturbed sample from
soft, fine-grained soils for undisturbed CBR or
density tests.
When using this method, first smooth the
ground surface and then press the sampling
collar and mold into the soil with moderate
Figure 15-15.-Section through a CBR mold.
Figure 15-16.-Trench cut around a cylinder.
pressure. Then excavate a trench around the
cylinder and again press the mold down over
the soil, using the hand driver or loading
bar if necessary. You can improvise a loading
bar from any suitably sized piece of tim-
ber. Trim the soil away from the sampling
collar carefully with a knife, cutting down-
ward and outward to avoid cutting into the
Figure 15-17.-Using a loading bar to drive a cylinder.
15-14
