Dr. Jintai Wang’s Personal Website

Jintai Wang, Ph.D., P.E.

Department of Civil Engineering

Oregon Institute of Technology

3201 Campus Dr., Klamath Falls, OR 97601

Phone: (541) 885-1504

Email: jintai.wang@oit.edu

• Soil dynamics and Earthquake Engineering
• Geotechnical Instrumentation
• Solid Waste Engineering
• Non-textbook Soils

Engineering Characterization of Diatomaceous Earth

Interest has been increasing in studying diatomaceous earth stemming from the challenges posed by their presence in various engineering projects, such as the US 97 at Wickiup Junction project in Oregon. At Wickiup Junction, an overpass crossing was being built to replace the last at-grade rail crossing on US 97, and the previously undetected presence of diatomaceous earth caused massive and uneven settlement under the earth embankments.

Diatomaceous earth consists of fossilized remains of diatoms, which have a highly varied and interlocking shape, giving the impression of strength until the skeletons crush under excessive stress. The shape of these diatoms is unique to each of the estimated 20,000 species, creating a highly varied material that may behave differently depending on the species encountered. The engineering properties and liquefaction potentials of diatomaceous earth are not well understood.

SEM image of diatomaceous earth sample 

This project aims to investigate the engineering characterization and liquefaction potential of diatomaceous earth. A series of geotechnical laboratory tests including grain-size distribution, Atterberg limits, specific gravity, direct shear, 1-D consolidation, and cyclic triaxial tests were performed. 

The figure below presents the cyclic responses of the diatomaceous earth sample with a confining pressure (σ_3c΄) = 103 kPa and a cyclic stress ratio (CSR) = 0.2. 

The paper summarizing the results of this project can be found here: https://ascelibrary.org/doi/abs/10.1061/9780784485316.014