Influence of Mazama Ash on the Unconfined Compressive Strength of a Soil from a Residential Development in Cheney, WA
Faculty Sponsor
Richard Orndorff, Eastern Washington University
Research Project Abstract
We tested soil from the Harvest Bluff (HB) residential development in Cheney, WA, which sits at the boundary between loess hills to the north and the Four Lakes Ice Age Flood path to the south. We also tested Mt. Mazama ash (5677 BC eruption), which is locally abundant in the Spokane-Cheney area, to assess the impact of volcanic ash on soil properties. We determined unconfined compressive strength (ASTM D2166-85) of HB soil, Mazama ash, and a combination of 50% of each sample by weight. Samples were compacted and tested at varying water contents to determine sample strength. Pure HB soil reached its maximum unconfined compressive strength (5486 psf) at 15% water content, pure Mazama ash (5347 psf) at 35% water content, and the mixed sample (4692 psf) at 20% water content. We hypothesize that Mazama ash will have similar impacts on the compressive strength of other soils undergoing development.
Session Number
PS2
Location
Graves Gym
Abstract Number
PS2-q
Influence of Mazama Ash on the Unconfined Compressive Strength of a Soil from a Residential Development in Cheney, WA
Graves Gym
We tested soil from the Harvest Bluff (HB) residential development in Cheney, WA, which sits at the boundary between loess hills to the north and the Four Lakes Ice Age Flood path to the south. We also tested Mt. Mazama ash (5677 BC eruption), which is locally abundant in the Spokane-Cheney area, to assess the impact of volcanic ash on soil properties. We determined unconfined compressive strength (ASTM D2166-85) of HB soil, Mazama ash, and a combination of 50% of each sample by weight. Samples were compacted and tested at varying water contents to determine sample strength. Pure HB soil reached its maximum unconfined compressive strength (5486 psf) at 15% water content, pure Mazama ash (5347 psf) at 35% water content, and the mixed sample (4692 psf) at 20% water content. We hypothesize that Mazama ash will have similar impacts on the compressive strength of other soils undergoing development.
