Bridge Abutment Soil Compaction Test
East Los Angeles College
University of California, San Diego
A new bridge is about to be erected in San Diego's Camp Elliot army base.
Azadeh Bozorgzadeh headed the design of the bridge. We tested the soil of the site
location in order to determine the optimum level of water to add in order for the soil to
have the best characteristics to support the bridge abutments. The preferred properties to
be improved are strength, compressibility, volume stability, erodibility, and hydraulic
Our modified soil compaction test required soil to be compacted into 5 layers in a
6'' mold. Each layer was given 56 blows from a 10-lbf hammer dropped from 18'' high,
exerting a total effort of 56,000 ft-lbf/ft3. The test was repeated 5 times until a
relationship between water content and dry unit weight of the soil was established. For
bridges, it is best to use 95% or more of the optimum recorded water content.
During my PEER Summer Internship at UCSD, I worked on two projects. The first
project consisted of setting up a laminar box on top of a shake table. I worked 8 hours a
day on jobs such as reparing holes in the laminar box bladder, assembling the strain
gauges on the aluminum pile, and cleaning the actuators. We completed the set up on
time, and were able to do the testing of the pile in sand and water.
For the second project, I worked with doctoral candidate Azadeh Bozorgzadeh. Ms.
Bozorgzadeh has designed a bridge that is being built in Camp Elliot army base in San
Diego, California. The construction of a bridge abutment will be the first step. The
conduction of a soil compaction test was necessary in order to determine the optimum
level of water to add to the soil.
Our objective was to discover how to allow the soil to have t