Geotechnical Analysis of the Impacts of Mazama Ash (5677 BC) on the California Bearing Ratio (CBR) of Soil from a Residential Construction Site in Cheney, WA
Faculty Sponsor
Richard Orndorff, Eastern Washington University
Research Project Abstract
We analyzed volcanic ash from Mt. Mazama, found in Turnbull National Wildlife Refuge south of Cheney, and soil from the Harvest Bluff residential development, located between loess hills and glacial outburst flood paths. Ash deposits beneath the surface in the region may not be properly represented by surficial analysis. To understand the possible effects this can have on construction of roads and runways, we conducted CBR (ASTM D1883) tests on the Mazama ash, 50% ash-Harvest Bluff mix, and Harvest Bluff soil. The CBR test is used to evaluate the penetration resistance of compacted soil and determines the suitability of soil for road construction. Results show a minimal increase in soil suitability from pure Harvest Bluff soil sample (28%) to 50% ash mix (31%). This allows its use as an excellent subgrade, good base and good subbase. Similar results are expected in other soils in the region.
Session Number
PS2
Location
Graves Gym
Abstract Number
PS2-r
Geotechnical Analysis of the Impacts of Mazama Ash (5677 BC) on the California Bearing Ratio (CBR) of Soil from a Residential Construction Site in Cheney, WA
Graves Gym
We analyzed volcanic ash from Mt. Mazama, found in Turnbull National Wildlife Refuge south of Cheney, and soil from the Harvest Bluff residential development, located between loess hills and glacial outburst flood paths. Ash deposits beneath the surface in the region may not be properly represented by surficial analysis. To understand the possible effects this can have on construction of roads and runways, we conducted CBR (ASTM D1883) tests on the Mazama ash, 50% ash-Harvest Bluff mix, and Harvest Bluff soil. The CBR test is used to evaluate the penetration resistance of compacted soil and determines the suitability of soil for road construction. Results show a minimal increase in soil suitability from pure Harvest Bluff soil sample (28%) to 50% ash mix (31%). This allows its use as an excellent subgrade, good base and good subbase. Similar results are expected in other soils in the region.
