Geotechnical Properties of Fluid Mud
Abstract
The goals of this project were as follows: determine the physical response of fluid and consolidated mud on water waves and quantify the changes in the consolidated mud bed that occur during the buildup towards and onset of sediment fluidization; and determine the relationship between in situ yield strength properties or the critical stress required for fluid mud to initiate flow, shear strength, and the rheologically determined properties of the mud, specifically the initial yield strength as determined with a rheometer in the laboratory. The scientific objective is to determine the role of fluid mud behavior in the dissipation of water-wave energy. This will be accomplished by supplying Alex Sheremet with data on the mud, which will be incorporated into Alex's model. Cruises to the Atchafalaya Basin were made to make in situ bearing strength measurements using the MKII Sting penetrometer through two parallel tracks, one to the east, in the vicinity of the river discharge, and one to the west, closer to the MURI site. Sediment cores were collected for shear strength measurements, grain size, water content, and organic matter. These measurements are complete and data are being compiled and analyzed. Additionally, geotechnical measurements of viscosity and yield strength were conducted using a variable shear rate/variable shear rheometer. Bearing strength measurements will be made in situ. Density and shear strength measurements will be made in the lab on cores. Sediment behavior and viscosity will be determined for variably dense mixes of fluid mud. The results from these analyses will provide parameters for the UF modeling efforts and will complement the geochronology work done by UT. The geotechnical data will be used to understand how mud properties change during the time during the spring season when river discharge peaks and then wanes. The data collected will be provided to Alex Sheremet for incorporation into his wave energy dissipation model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2008
- Accession Number
- ADA514595
Entities
People
- Allen H. Reed
Organizations
- United States Naval Research Laboratory