Figure A2. Test apparatus for coarse-grained soils.
Figure A3. Apparatus in kneading compactor.
layers in the test specimen. The apparatus was placed in the kneading compactor
and compacted in five layers at optimum density and moisture content (Fig. A3).
The kneading compactor was the CS 1200 electrohydraulic kneading compactor
manufactured by James Cox & Sons, Inc. It was modified to make 2.8-in.- (71-mm-)
and 6-in.- (152-mm-) diam. samples. Compaction was accomplished by applying a
kneading pressure to the specimen through a tamping foot by means of a con-
trolled dynamic force. The compactor has a rotating table and is electronically timed
to the tamper foot. This kneading compactor can be programmed for pressure
time curves, repetition of rates, extended dwell times at peak pressure, and a vari-
ety of predetermined totals of compaction counts. The fine-grained material was
compacted with a 3.15-in.2 (20.26-cm2) tamper. The coarse-grained material was
compacted with a 9.6-in.2 (62.06-cm2) tamper.
At the end of sample compaction, the rings were extruded from the outer mold.
For the 2.8-in. (71-mm) samples, a hand piston was used (Fig. A4). The additional
layer was carefully removed prior to determining the density and moisture content
in the remaining six layers (Fig. A5). The rings were removed one by one and the
density and moisture content of each layer are determined (Fig A6). The same pro-
cedure was done for the coarse-grained soils. By this trial and error process, the
required kneading pressures and tamps were developed for a uniform density and
moisture content test specimen. Once the correct pressure and tamps were deter-
mined for each soil, the procedure was repeated five times to assure that the proce-
dure produced repeatable results. For the marine clay, it was anticipated that test