| Autor: |
Morin, RH, Olsen, HW, Nelson, KR, Gill, JD |
| Zdroj: |
Geotechnical Testing Journal; December 1989, Vol. 12 Issue: 4 p302-307, 6p |
| Abstrakt: |
A graphical method has been developed for determining the coefficient of consolidation from the transient phases of a flow-pump permeability test. The flow pump can be used to infuse fluid into or withdraw fluid from a laboratory sediment specimen at a constant volumetric rate in order to obtain data that can be used to calculate permeability using Darcy's law. When the initial transient-response curve (hydraulic head as a function of time) generated by this test is examined analytically in terms of a one-dimensional consolidation process, representative type-curve solutions to the associated forced-flow and pressure-decay models are derived. These curves provide the basis for graphically evaluating the permeability k, the coefficient of consolidation cv, and the coefficient of volume change mv. The curve-matching technique is easy and rapid, and it can be applied to results of forced-flow tests, both infusion and withdrawal, as well as to subsequent pressure-decay records. Values of k, cv, and mvfor a laterally confined kaolinite specimen were determined by this graphical method and appear to be in reasonably good agreement with numerically derived estimates (within 20%). Discrepancies between the two sets of results seem to be largely a function of data quality rather than of method of analysis. Where responses of hydraulic head as a function of time are apparently unaffected by experimental sources of error, agreement is excellent (within 4%). Application of this graphical method to triaxial testing has inherent uncertainties, because the solution curves that describe one-dimensional deformation are used to analyze a three-dimensional process. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
