MECHANICAL COMPACTION OF SOILS FOR ENGINEERING PURPOSES

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MECHANICAL COMPACTION OF SOILSFOR ENGINEERING
PURPOSES

• J. David Rogers, Ph.D., P.E., R.G.
• Karl F. Haselmann Chair
• in Geological Engineering
• University of Missouri-Rolla

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Part 1ORIGINS OF MECHANICAL COMPACTION
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THE FRESNO GRADER

• Abajiah McCall invented the horse-drawn dirt
  bucket scrapper in Fresno County, California in
  1885. It became known as the Fresno Scrapper
  and was widely employed as the prime earth moving
  device until the widespread advent of
  self-powered scrappers in the 1930s.

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LOAD COMPACTION

• In the early days large embankments were
  constructed by side-dumping rail cars or wagons
  from temporary wooden trestles, as shown here.
  Engineers assumed that the soil would compact
  under its own dead load.

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• The sheepsfoot roller was patented in 1904 in Los
  Angeles, using railroad spikes attached to a
  hollow drum. The drum was filled with sand and
  water to increase its weight.

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• The sheepsfoot roller imparts the greatest
  compactive effort through load concentration on
  the narrow spikes. The spikes employ kneading
  compaction to densify cohesive soils.

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• This Hyster grid roller was used to disaggregate
  bedrock particles for incorporation in earthfill
  embankments, beginning in the mid-1930s. Note
  concrete ballast blocks. Mike Scullin provides
  scale.

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• Bouquet Canyon earthfill embankment dams were
  constructed by the Los Angeles Department of
  Water Power between 1931-33 as a replacement
  for the St. Francis Dam, which failed in 1928.
  

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COMPACTION TESTS

• Ralph Proctor was a field engineer on the Bouquet
  Canyon Dams in 1931-33. He was told to devise a
  method of testing compacted fill so the City of
  Los Angeles could demonstrate to the world that
  they were constructing the safest reservoir
  possible.

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PROCTOR COMPACTION TEST
Ralph Proctor 1894-1962

• Proctor devised an alternative method to that
  used by the California Division of Highways,
  which compared dry unit density to moisture
  content for a given compactive effort.