1、Designation: D5472/D5472M 14Standard Test Method forDetermining Specific Capacity and EstimatingTransmissivity at the Control Well1This standard is issued under the fixed designation D5472/D5472M; the number immediately following the designation indicates theyear of original adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test describes a procedure for conducting a specificcapacity test, computing the speci
3、fic capacity of a control well,and estimating the transmissivity in the vicinity of the controlwell. Specific capacity is the well yield per unit drawdown atan identified time after pumping started.1.2 This test method is used in conjunction with TestMethod D4050 for conducting withdrawal and inject
4、ion welltests.1.3 The method of determining transmissivity from specificcapacity is a variation of the nonequilibrium method of Theis(1)2for determining transmissivity and storage coefficient of anaquifer. The Theis nonequilibrium method is given in TestMethod D4106.1.4 LimitationsThe limitations of
5、 the technique for deter-mining transmissivity are primarily related to the correspon-dence between the field situation and the simplifying assump-tions of the Theis method.1.5 The scope of this test method is limited by the capabili-ties of the apparatus.1.6 All observed and calculated values shall
6、 conform to theguidelines for significant digits and rounding established inPractice D6026.1.6.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that sho
7、uld generally be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or reduce significant digits of reported data to com-mensurate with these
8、considerations. It is beyond the scope ofthis standard to consider significant digits used in analysismethods for engineering design.1.7 The values stated in SI units are to be regarded asstandard. Rationalized inch-pound units also are used in thisstandard. Each system of units is to be regarded se
9、parately asstandard.1.8 This standard may involve hazardous materials,operations, and equipment. This standard does not addresssafety problems associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicabi
10、lity of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D653 Terminology Relating to Soil, Rock, and ContainedFluidsD2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing
11、and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4050 Test Method for (Field Procedure) for Withdrawaland Injection Well Testing for Determining HydraulicProperties of Aquifer SystemsD4106 Test Method for (Analytical Procedure) for Deter-mining Transmissivity and Stor
12、age Coefficient of Non-leaky Confined Aquifers by the Theis NonequilibriumMethodD6026 Practice for Using Significant Digits in GeotechnicalData3. Terminology3.1 For common definitions of terms in this standard, referto Terminology D653.3.2 Symbols and Dimensions:3.2.1 Khydraulic conductivity LT11Thi
13、s test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved June 15, 2014. Published August 2014. Originallyapproved in 1993. Last previous edition approved
14、in 2005 as D547293(2005),which was withdrawn February 2014 and reinstated in June 2014. DOI: 10.1520/D5472_D5472M-14.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cust
15、omer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
16、PA 19428-2959. United States13.2.2 msaturated thickness L3.2.3 Qdischarge L3T13.2.4 Q/sspecific capacity (L3T1)L13.2.5 rwell radius L3.2.6 sdrawdown L3.2.7 Sstorage coefficient dimensionless3.2.8 Ttransmissivity L2T13.2.9 Tprovisional value of transmissivity L2T13.2.10 telapsed time of pumping T3.2.
17、11 ur2S/4Tt dimensionless3.2.12 W(u)well function of “u” dimensionless3.2.13 c1W(u)/44. Summary of Test Method4.1 A control well is equipped with an accumulated watermeter or other well yield measuring device and the static waterlevel determined after conditioning.4.2 After a conditioning pumpdown,
18、the well is pumpedcontinuously and measurements collected. Determination ofthe specific capacity and an estimate of the transmissivity ofthe well is then calculated.5. Significance and Use5.1 Assumptions of the Theis (1) equation affect specificcapacity and transmissivity estimated from specific cap
19、acity.These assumptions are given below:5.1.1 Aquifer is homogeneous and isotropic.5.1.2 Aquifer is horizontal, of uniform thickness, and infi-nite in areal extent.5.1.3 Aquifer is confined by impermeable strata on its upperand lower boundaries.5.1.4 Density gradient in the flowing fluid must be neg
20、li-gible and the viscous resistance to flow must obey DarcysLaw.5.1.5 Control well penetrates and receives water equallyfrom the entire thickness of the aquifer.5.1.6 Control well has an infinitesimal diameter.5.1.7 Control well discharges at a constant rate.5.1.8 Control well operates at 100 percen
21、t efficiency.5.1.9 Aquifer remains saturated throughout the duration ofpumping.5.2 Implications of Assumptions and Limitations of Method.5.2.1 The simplifying assumptions necessary for solution ofthe Theis equation and application of the method are neverfully met in a field test situation. The satis
22、factory use of themethod may depend upon the application of one or moreempirical correction factors being applied to the field data.5.2.2 Generally the values of transmissivity derived fromspecific capacity vary from those values determined fromaquifer tests utilizing observation wells. These differ
23、ences mayreflect 1) that specific-capacity represents the response of asmall part of the aquifer near the well and may be greatlyinfluenced by conditions near the well such as a gravel pack orgraded material resulting from well development, and 2)effects of well efficiency and partial penetration.5.
24、2.3 The values of transmissivity estimated from specificcapacity data are considered less accurate than values obtainedfrom analysis of drawdowns that are observed some distancefrom the pumped well.NOTE 1The quality of the result produced by this standard isdependent on the competence of the personn
25、el performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in
26、itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.5.3 Withdrawal well test field procedures are used withappropriate analytical procedures in appropriate hydrogeologi-cal sites to determine transmissivity and st
27、orage coefficient ofaquifers and hydraulic conductivity of confining beds.6. Apparatus6.1 Various types of equipment can be used to withdraw orinject water into the control well, measure withdrawal andinjection rates, and measure water levels. The test proceduremay be conducted with different types
28、of equipment to achievesimilar results. The objectives to be achieved by the use of theequipment are given in this section and in Sections 7 and 8.Theselection of equipment and measuring apparatus will beevaluated to ensure that sufficient accuracy and sensitivity willbe provided for the later evalu
29、ation of data by Test MethodD4106.6.2 Control WellDischarge or injection well test methodsrequire that water be withdrawn from or injected into a singlewell. This well, known as the control well, must be drilled andcompleted such that it transmits water to or from the aquifer(usually the entire thic
30、kness of the aquifer) at rates such that ameasurable water level change will occur at observation wells.The control well should be as efficient as possible, to reduce thehead loss between the aquifer and the well. Well developmentshould be as complete as possible to eliminate additionalproduction of
31、 sand or silt and consequent changes in wellefficiency and pumping water levels during the test. Thecuttings from the control well should be described and re-corded according to Practice D2488. The analytical methodselected for analysis of the data may specify certain dimensionsof the control well s
32、uch as screen length and depth of screenplacement. Specific requirements for control wells may begiven in standards for specific analytical methods (see, forexample, Test Method D4106).6.3 Observation Wells or PiezometersNumbers of obser-vation wells and their distance from the control well and thei
33、rscreened interval may be dependent upon the test method to beemployed. Refer to the analytical test method to be used forspecifications of observation wells (see, for example, TestMethod D4106).6.4 Control Well PumpA pump capable of withdrawal ofa constant or predetermined variable rate of water fr
34、om thecontrol well. The pump and motor should be adequately sizedfor the designed pumping rate and lift. The pump or motormust be equipped with a control mechanism to adjust dischargerate. In the case of diesel-, gasoline-, or natural-gas-fueledD5472/D5472M 142engines, throttle settings should allow
35、 for small adjustments inpumping rates. Pumps equipped with electric motors areusually controlled by adjusting back pressure on the pumpthrough a gate valve in the discharge line. Take care to selecta discharge rate small enough such that the rate can bemaintained throughout the test without fully o
36、pening the gatevalve. If neither method of control is practical, split thedischarge and route part of the discharge back to the wellthrough a separate discharge line. If water is withdrawn, thedischarge should be at a distance sufficiently away from thearea to prevent recharging back into the aquife
37、r being tested.6.5 Many aquifer tests are made at “sites of opportunity,”that is, using existing production wells as the control well andusing other existing wells for observation of water level. Insuch cases the locations and screened intervals of the wellsshould be compatible with the requirements
38、 of the method oftest analysis.6.6 Water-Level Measurement EquipmentManual mea-surements can be made with a steel tape or electric tape, witha mechanical recorder linked to a float, or combination ofpressure transducer and electronic data logger.6.6.1 Mechanical RecordersMechanical recorders employa
39、 float in the well to produce a graphic record of water levelchanges. Early in the test, it may be difficult to distinguishsmall increments of time on the recorder chart, therefore therecorder should be supplemented with additional early timemeasurements or by marking the trace of an automatic water
40、-level recorder chart and recording the time by the mark. Checkthe mechanical recorder periodically throughout the test usingthe steel tape.6.6.2 Pressure Transducers and Electronic DataLoggersA combination of a pressure transducer and elec-tronic data logger can provide rapid measurements of waterl
41、evel change, and can be programmed to sample at reducedfrequency late in the test. Select the pressure transducer tomeasure pressure changes equivalent to the range of expectedwater level changes. Check the transducer in the field byraising and lowering the transducer a measured distance in thewell.
42、 Also check the transducer readings periodically with asteel tape.6.6.3 Equipment used for measuring flows, and water levelsshould have calibration records, or be calibrated for the test.6.7 Sand Content Measurement DeviceApparatus to mea-sure the sand content in discharged water. Cone Types (forexa
43、mple, Imhoff) can be used for higher concentrations of sandin the discharge water and centrifugal sand separators (forexample, Rossum) can be used for lower levels and arecommercially available and commonly used.7. Conditioning Procedures7.1 Conditioning procedures are conducted before the test toen
44、sure that the control well is properly equipped and that thewell discharge and water-level measuring equipment is opera-tional.7.1.1 Equip the control well with a calibrated accumulatingwater meter or another type of calibrated well yield measuringdevice.7.1.2 Provide the control well with a system
45、for maintaininga constant discharge.7.1.3 Equip control well for measuring the pretest waterlevel (prepumping water level) and pumping water levelsduring the specific capacity test.7.1.4 Measure static water level immediately before startingthe pump.7.1.5 Start pump and simultaneously measure elapse
46、d timewith a stop watch or data recorder. After 3 to 5 minutes wellyield and drawdown should be measured and recorded.7.1.6 If all the equipment is working properly, drawdownmeasurements can be obtained, and constant dischargemaintained, the equipment check can be ended.7.1.7 Cease pumping and allow
47、 the water level to recover toits prepumping level before the specific capacity test procedureis initiated.8. Test Procedure8.1 Initiate well discharge.8.2 Measure the well yield and pumping water level in thecontrol well at predetermined time intervals, for example, 2-,5-, 10-, 20-, 30-, minutes af
48、ter discharge is initiated.Adjust thedischarge rate during the test to maintain discharge within 5 %of the rate planned. Discharge waters should be at a distancesufficiently away from the area to prevent recharging back intothe aquifer being tested.8.3 While test continues make the following calcula
49、tions:8.3.1 Adjust drawdown for effects of desaturation of theaquifer, if applicable (see Section 9).8.3.2 Determine the specific capacity (see Section 11) andestimate transmissivity (see Section 12). If well bore storageeffects are negligible (see Section 10), compare the new valueof T to the value used to calculate c1, if the value is within10 %, the test can be terminated.8.3.3 If control well is not screened through the entirethickness of the aquifer, estimate the transmissivity of theaquifer following procedure in Sectio
