A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

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On the application of storage coefficient determination by quasi-steady-state flow

Hydrology Research ◽

10.2166/nh.2005.0002 ◽

2005 ◽

Vol 36 (1) ◽

pp. 13-20 ◽

Cited By ~ 2

Author(s):

Mehmet E. Birpinar ◽

Ayhan Gazioglu

Keyword(s):

Steady State ◽

Quasi Steady State ◽

Confined Aquifer ◽

Steady State Flow ◽

Steady State Condition ◽

Storage Coefficient ◽

Unconfined Aquifers ◽

Aquifer Test ◽

Order Of Magnitude ◽

Observation Wells

A simple analytical method has been used for estimating the storage coefficient provided that transmissivity of the aquifer is known at the quasi-steady-state condition in confined or unconfined aquifers. The application of the method has been performed for unconfined and confined aquifer test data in Chaj Doab, Pakistan with observation wells and compared with conventional methods in the groundwater flow literature dealing with pumping tests. The results from the methodology presented in this paper conform well in practice with the results obtained from the traditional methods on the basis of order of magnitude.

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Storage Coefficient Determination from Quasi-Steady State Flow

Hydrology Research ◽

10.2166/nh.1987.0008 ◽

1987 ◽

Vol 18 (2) ◽

pp. 101-110 ◽

Cited By ~ 6

Author(s):

Zekâi Şen

Keyword(s):

Steady State ◽

Large Diameter ◽

Field Measurements ◽

Classical Type ◽

Quasi Steady State ◽

Steady State Flow ◽

Storage Coefficient ◽

State Flow ◽

Unconfined Aquifers ◽

Confined And Unconfined Aquifers

A method has been proposed for determining a unique storage coefficient value for confined and unconfined aquifers tapped by a large diameter well. The prerequisites for the application of this method are estimation of the transmissivity value and the field measurements of well radius, pumping discharge and time-drawdown measurements at large times, or preferably at the steady or quasi-steady state flow conditions. The application of the method does not require any complicated mathematical procedure of the classical type curve matching procedures. It is recommended especially as a supplementary method to the existing techniques in determining the storage coefficient.

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Piping Fluid Transients Made Simple: Part I — Theory of the SSFFC Methodology

Volume 3: Design and Analysis ◽

10.1115/pvp2005-71010 ◽

2005 ◽

Author(s):

Zakaria N. Ibrahim

Keyword(s):

Fluid Flow ◽

Steady State ◽

Fluid Pressure ◽

Piping System ◽

Consecutive Series ◽

Quasi Steady State ◽

Sound Waves ◽

Steady State Flow ◽

State Flow ◽

Pipe Segment

Piping systems transporting fluid between plant components are subjected to a variety of anticipated and/or postulated flow changes that disturb their steady state operations. These changes cause the fluid flow to accelerate and/or decelerate. However, consideration of fluid elasticity transforms these disturbances into weak and/or strong propagating sound waves, depending upon the abruptness level of the fluid state change. This generates dynamic forces on the pipe segments of the piping system. A simple concept for understanding the piping fluid transient phenomenon from its physical perspective is presented. The piping system consists of several pipe segments, each segment having a constant cross-sectional flow area. The pipe segment is further divided into a consecutive series of zones. Each zone comprises two or three sub-zones of quasi steady state flow. The sub-zones are separated by interface fronts at which the jump in fluid pressure and velocity occurs across them. These fronts propagate and clash with each other to create the next temporal set of sub-zones quasi steady state flow. This method is denoted in this paper as steady state flow fronts clashing ‘SSFFC’. Clashing between the incident, transmitted and/or reflected wave fronts within the zone is introduced. As a precursor to the second part of a two-part publication, the SSFFC is physically illustrated and mathematically formulated to establish the temporal fluid steady state contained within each sub-zone constituting the pipe segment. The developed formulations are comparable to those instituted by the conventional method of characteristics. The pipe segment generalized fluid flow transient forces based on SSFFC methodology are also formulated. In the concurrent publication that forms part two of this presentation [8], sample applications of SSFFC methodology are illustrated.

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A potential systematic error in laboratory testing of very loose sands

Canadian Geotechnical Journal ◽

10.1139/t87-058 ◽

1987 ◽

Vol 24 (3) ◽

pp. 462-466 ◽

Cited By ~ 40

Author(s):

J. A. Sladen ◽

G. Handford

Keyword(s):

Steady State ◽

Void Ratio ◽

Flow Line ◽

Simple Calculation ◽

Triaxial Tests ◽

Steady State Flow ◽

Laboratory Procedure ◽

State Flow ◽

Potential Error

There is a potential error in the determination of specimen void ratio in triaxial tests on very loose sands. This error can be attributed to densification during final saturation. The result can be an error in the determination of the location of the steady state flow line in void ratio – stress space. Stress levels on the steady state flow line at a given void ratio may be in error by two orders of magnitude. If carried through to the analysis of susceptibility to liquefaction, this potential error could be extremely unconservative. Test results are presented that illustrate this potential source of error. A laboratory procedure is proposed that provides a simple calculation of final specimen void ratio and is potentially more accurate than presently used procedures. Key words: triaxial testing, sand, liquefaction, steady state.

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