Record Details
Fabrics in subdrains : mechanisms of filtration and the measurement of permeability
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Fabrics in subdrains : mechanisms of filtration and the measurement of permeability |
| Names |
Copeland, Jane Ann
(creator) Bell, J. R. (advisor) |
| Date Issued | 1979-06-07 (iso8601) |
| Note | Graduation date: 1980 |
| Abstract | The roles of fabrics in subdrains are identified for normal groundwater flow conditions to determine hydraulic and pore characteristics necessary for design considerations. Two conditions are discussed: (1) the fabric in direct contact with the soil to provide mechanical support, and (2) the fabric as a filter to remove soil particles in suspension in water. If direct contact is maintained between the soil and fabric, control of the hydraulic gradient and/or pore size will prevent soil migration and fabric plugging by soil particles. If toe fabric is a filter in t:ne sense that it removes soil particles suspended in water, the fabric will plug. For tnis case a method of controlling piping of suspended soil particles by relating a soil grain size to the coefficient of fabric permeability is proposed. Relationships between a soil grain size, the soil Reynolds number, and the soil cake porosity are suggested as means of evaluating the effect of fabric plugging and soil cake formation. An experimental design is Proposed to evaluate the applicability of the proposed equations for the critical hydraulic gradient and the control of plugging and piping. Air permeability and falling head water permeability tests were performed. The falling head test provided for water and fabric deairing. Turbulence was found to exist when testing one layer of fabric but laminar flow was indicated when testing multiple layers. Comparison between air and water permeability test results indicates that either method can predict fabric permeability with satisfactory accuracy. |
| Genre | Thesis/Dissertation |
| Topic | Drainage |
| Identifier | http://hdl.handle.net/1957/42818 |
