FORMAT
BOOKS
PACKAGES
EDITION
PUBLISHER
CONTENT TYPE
Act
Admin Code
Announcements
Bill
Book
CADD File
CAN
CEU
Charter
Checklist
City Code
Code
Commentary
Comprehensive Plan
Conference Paper
County Code
Course
DHS Documents
Document
Errata
Executive Regulation
Federal Guideline
Firm Content
Guideline
Handbook
Interpretation
Journal
Land Use and Development
Law
Legislative Rule
Local Amendment
Local Code
Local Document
Local Regulation
Local Standards
Manual
Model Code
Model Standard
Notice
Ordinance
Other
Paperback
PASS
Periodicals
PIN
Plan
Policy
Product
Product - Data Sheet
Program
Provisions
Requirements
Revisions
Rules & Regulations
Standards
State Amendment
State Code
State Manual
State Plan
State Standards
Statute
Study Guide
Supplement
Sustainability
Technical Bulletin
All
|
Description of ASTM-D4105 2008ASTM D4105 - 96(2008)Standard Test Method for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined Aquifers by the Modified Theis Nonequilibrium MethodActive Standard ASTM D4105 | Developed by Subcommittee: D18.21 Book of Standards Volume: 04.08 ASTM D4105Significance and Use Assumptions : Well discharges at a constant rate, Q . Well is of infinitesimal diameter and fully penetrates the aquifer, that is, the well is open to the full thickness of the aquifer. The nonleaky aquifer is homogeneous, isotropic, and areally extensive. A nonleaky aquifer receives insignificant contribution of water from confining beds. Discharge from the well is derived exclusively from storage in the aquifer. The geometry of the assumed aquifer and well conditions are shown in Fig. 1. Implications of Assumptions :
Implicit in the assumptions are the conditions of radial flow. Vertical flow components are induced by a control well that partially penetrates the aquifer, that is, not open to the aquifer
through its full thickness. If the control well does not fully penetrate the aquifer, the nearest piezometer or partially penetrating observation well should be located at a distance,
r , beyond which vertical flow components are negligible, where according to Reed (5)
This section applies to distance-drawdown calculations of transmissivity and storage coefficient and time-drawdown calculations of storage coefficient. If possible, compute transmissivity
from time-drawdown data from wells located within a distance, r , of the pumped well using data measured after the effects of partial penetration have become
constant. The time at which this occurs is given by Hantush (6) by: Fully penetrating observation wells may be placed at less than distance r from the control well. Observation wells may be on the same or on various radial lines from the control well.
The Theis method assumes the control well is of infinitesimal diameter. Also, it assumes that the water level in the control well is the same as in the aquifer contiguous to the well. In
practice these assumptions may cause a difference between the theoretical drawdown and field measurements of drawdown in the early part of the test and in and near the control well. Control
well storage is negligible after a time, t , given by the following equation after weeks (7) .
Application of Theis Nonequilibrium Method to Unconfined Aquifers : Although the assumptions are applicable to confined conditions, the Theis solution may be applied to unconfined aquifers if drawdown is small compared with the saturated thickness of the aquifer or if the drawdown is corrected for reduction in thickness of the aquifer and the effects of delayed gravity yield are small.
Reduction in Aquifer Thickness In an unconfined aquifer, dewatering occurs when the water levels decline in the vicinity of a pumping
well. Corrections in drawdown need to be made when the drawdown is a significant fraction of the aquifer thickness as shown by Jacob (8) . The drawdown, s , needs to be replaced by s ? , the drawdown that would occur in an equivalent confined aquifer, where:
Gravity Yield Effects In unconfined aquifers, delayed gravity yield effects may invalidate measurements of drawdown during the early
part of the test for application to the Theis method. Effects of delayed gravity yield are negligible in partially penetrating observation wells at a distance, r ,
from the control well, where:
after the time, t , as given in the following equation from Neuman (9) :
For fully penetrating observation wells, the effects of delayed yield are negligible at the distance, r , in Eq 11 after one tenth of the time given in the Eq 12.
1. Scope 1.1 This test method covers an analytical procedure for determining transmissivity and storage coefficient of a nonleaky confined aquifer under conditions of radial flow to a fully penetrating well of constant flux. This test method is a shortcut procedure used to apply the Theis nonequilibrium method. The Theis method is described in Test Method D4106 . 1.2 This test method is used in conjunction with the field procedure given in Test Method D4050 . 1.3 Limitations The limitations of this test method are primarily related to the correspondence between the field situation and the simplifying assumptions of this test method (see 5.1). Furthermore, application is valid only for values of u less than 0.01 ( u is defined in Eq 2, in 8.6). 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
ASTM Standards D653 Terminology Relating to Soil, Rock, and Contained Fluids D4043 Guide for Selection of Aquifer Test Method in Determining Hydraulic Properties by Well Techniques D4050 Test Method for (Field Procedure) for Withdrawal and Injection Well Tests for Determining Hydraulic Properties of Aquifer Systems D4106 Test Method for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined Aquifers by the Theis Nonequilibrium Method Keywords aquifer tests; aquifers; confined aquifers; control wells; groundwater; hydraulic properties; observation wells; storage coefficient; transmissivity; unconfined aquifers; Aquifers; Coefficient of storage; Confined aquifers; Control wells; Field testing--ground water/aquifers; Ground water; Hydraulic conductivity/transmissivity; Observation wells; Storativity; Theis methods of analysis; Transmissivity and reflectivity; Unconfined/unconsolidated aquifers; ICS Code ICS Number Code 93.160 (Hydraulic construction) DOI: 10.1520/D4105-96R08 ASTM International is a member of CrossRef. ASTM D4105This book also exists in the following packages...Subscription InformationMADCAD.com ASTM Standards subscriptions are annual and access is unlimited concurrency based (number of people that can access the subscription at any given time) from single office location. For pricing on multiple office location ASTM Standards Subscriptions, please contact us at info@madcad.com or +1 800.798.9296.
Some features of MADCAD.com ASTM Standards Subscriptions are: - Immediate Access: As soon as the transaction is completed, your ASTM Standards Subscription will be ready for access.
For any further information on MADCAD.com ASTM Standards Subscriptions, please contact us at info@madcad.com or +1 800.798.9296.
About ASTMASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence. ASTM’s leadership in international standards development is driven by the contributions of its members: more than 30,000 of the world’s top technical experts and business professionals representing 150 countries. Working in an open and transparent process and using ASTM’s advanced electronic infrastructure, ASTM members deliver the test methods, specifications, guides, and practices that support industries and governments worldwide. |
GROUPS
|