1、BRITISH STANDARDSoil quality Determination of unsaturated hydraulic conductivity and water-retention characteristic Winds evaporation methodICS 13.080.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g
2、40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 11275:2014National forewordThis British Standard is the UK implementation of EN ISO 11275:2014. It is identical to ISO 11275:2004. It supersedes BS ISO 11275:2004, which is withdrawn.The UK participation in its preparation was entrusted
3、to Technical Committee EH/4, Soil quality.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a Bri
4、tish Standard cannot confer immunity from legal obligations.BS EN ISO 11275:2014This British Standard waspublished under the authorityof the Standards Policy andStrategy Committee on13 July 2004Amendments/corrigenda issued since publicationDate Comments 31 May 2014 This corrigendum renumbers BS ISO
5、11275:2004 as BS EN ISO 11275:2014ISBN 978 0 580 82151 6 The British Standards Institution 2014. Published by BSI Standards Limited 2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11275 March 2014 ICS 13.080.40 English Version Soil quality - Determination of unsaturated hydraulic conduc
6、tivity and water-retention characteristic - Winds evaporation method (ISO 11275:2004) Qualit du sol - Dtermination de la conductivit hydraulique en milieu non satur et de la caractristique de rtention en eau - Mthode par vaporation de Wind (ISO 11275:2004) Bodenbeschaffenheit - Bestimmung der ungest
7、tigten hydraulischen Leitfhigkeit und des Wasserrckhaltevermgens - Verdunstungsverfahren nach Wind (ISO 11275:2004) This European Standard was approved by CEN on 13 March 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Eu
8、ropean Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versi
9、ons (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria,
10、Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Sw
11、itzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nati
12、onal Members. Ref. No. EN ISO 11275:2014 EiiForeword The text of ISO 11275:2004 has been prepared by Technical Committee ISO/TC 190 “Soil quality” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 11275:2014 by Technical Committee CEN/TC 345 “Characterizat
13、ion of soils” the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2014, and conflicting national standards shall be withdrawn at the latest by Septem
14、ber 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN-CENELEC Internal Regulations, the national standards or
15、ganizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembour
16、g, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 11275:2004 has been approved by CEN as EN ISO 11275:2014 without any modification. BS EN ISO 11275:2014 EN ISO 11275:2014 (E)ISO
17、 72114002:5)E( ISO 4002 r llAithgs reservde iiiContents Page1 Scope 12 Normative references 13 Terms and definitions 14 Symbols 25 Principle 36 Apparatus . 37 Procedure . 48 Expression of results 99 Accuracy . 910 Test report 9Bibliography . 11BS EN ISO 11275:2014 ISO 11275:2004iv ISO 4002 All rithg
18、s reresvdeIntroductionSoil water content and matric pressure are related to each other and determine the water-retentioncharacteristics of a soil. Soil water, which is in equilibrium with free water, is at zero matric pressure (or suction)and either the soil is saturated or the gaseous phase occurs
19、only as small bubbles. As a saturated soil dries, thematric pressure decreases (i.e. becomes more negative), and the largest pores empty of water. Progressivedecreases in matric pressure will continue to empty finer pores until eventually water is held in only the finestpores. Not only is water remo
20、ved from soil pores, but the films of water held around soil particles are reduced inthickness. Therefore, a decreasing matric pressure is associated with decreasing soil water content8,9.Laboratory or field measurements of these two parameters can be made; and the relationship (which can bereported
21、 graphically, in tabular form, or possibly as an equation) is called the soil water-retention characteristic.The relationship extends from saturated soil to oven-dry soil (approximately to about matricpressure).The soil water-retention characteristic is different for each soil type. The shape and po
22、sition of the curve relativeto the axes depend on soil properties such as texture, density and hysteresis associated with the wetting anddrying history. Individual points on the water-retention characteristic curve may be defined for specific purposes.The hydraulic conductivity is a measure of the r
23、ate at which liquid water can move through the soil under theinfluence of variations in matric pressure from point to point within the soil. The hydraulic conductivity ofunsaturated soil depends on the same factors as does the soil water-retention characteristic, also showinghysteresis. As a saturat
24、ed soil dries, the hydraulic conductivity decreases, and it is convenient to express thehydraulic conductivity corresponding to the soil water-retention characteristic as a function of the decreasingmatrix pressure.The results obtained using these methods can be used, for example: to provide an asse
25、ssment of the equivalent pore-size distribution (e.g. identification of macro- and micro-pores); to determine indices of plant-available water in the soil and to classify soil accordingly (e.g. for irrigationpurposes); to determine the drainable pore space (e.g. for drainage design, pollution risk a
26、ssessments); to monitor changes in the structure of a soil (caused by e.g. tillage, compaction or addition of organic matteror synthetic soil conditioners); to ascertain the relationship between the negative matric pressure and other soil physical properties (e.g.hydraulic conductivity, thermal cond
27、uctivity); to determine water content at specific negative matric pressures (e.g. for microbiological degradationstudies); to estimate other soil physical properties.0 kPa 106kPaBS EN ISO 11275:2014 ISO 11275:2004ANRETNIITOTS LANDNADRA ISO 72114002:5)E( ISO 4002 r llAithgs reservde 1Soil quality Det
28、ermination of unsaturated hydraulic conductivity and water-retention characteristic Winds evaporation method1ScopeThis International Standard specifies a laboratory method for the simultaneous determination in soils of theunsaturated hydraulic conductivity and of the soil water-retention characteris
29、tic. It is applicable only tomeasurement of the drying or desorption curve. Application of the method is restricted to soil samples whichare, as far as possible, homogeneous. The method is not applicable to soils which shrink in the range of matrichead to .The range of the determination of the condu
30、ctivity depends on the soil type. It lies between matric heads ofapproximately and .The range of the determination of the water-retention characteristic lies between matric heads of approximatelyand .NOTE 1 An infiltrometer method can be used to determine hydraulic conductivities near saturation.NOT
31、E 2 ISO 11274 gives methods to determine the water-retention characteristic for matric heads between and.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the l
32、atest edition of the referenced document(including any amendments) applies.ISO 10381-1, Soil quality Sampling Part 1: Guidance on the design of sampling programmesISO 10381-4, Soil quality Sampling Part 4: Guidance on the procedure for investigation of natural, near-natural and cultivated sitesISO 1
33、1274, Soil quality Determination of the water-retention characteristic Laboratory methodsISO 11276, Soil quality Determination of pore water pressure Tensiometer methodISO 11461, Soil quality Determination of soil water content as a volume fraction using coring sleeves Gravimetric method3 Terms and
34、definitionsFor the purposes of this document, the following terms and definitions apply.hm= 0cm hm= 800 cmhm= 50 cm hm= 700 cmhm= 0cm hm= 800 cm0cm15 000 cmBS EN ISO 11275:2014 ISO 11275:2004ISO :57211(4002)E2 ISO 4002 All rithgs reresvde3.1 hydraulic conductivityfactor of proportionality between th
35、e soil water flux density, , and the hydraulic gradient in Darcysequation, assuming isotropic conditions, i.e.NOTE For the purposes of this document, conductivity is used synonymously for unsaturated hydraulic conductivity.3.2 soil water-retention characteristicretention characteristicrelation betwe
36、en soil water content and soil matric head of a given soil (sample)3.3 gravitational headamount of work that must be done in order to transport reversibly and isothermally an infinitesimal quantity ofwater, identical in composition to the soil water, from a pool at a specified elevation and at atmos
37、phericpressure, to a similar pool at the elevation of the point under consideration, divided by the mass of watertransported3.4 matric headamount of work that must be done in order to transport reversibly and isothermally an infinitesimal quantity ofwater, identical in composition to the soil water,
38、 from a pool at the elevation and the external gas pressure of thepoint under consideration, to the soil water at the point under consideration, divided by the mass of watertransported3.5 pneumatic headamount of work that must be done in order to transport reversibly and isothermally an infinitesima
39、l quantity ofwater, identical in composition to the soil water, from a pool at atmospheric pressure and at the elevation of thepoint under consideration, to a similar pool at the external gas pressure of the point under consideration, dividedby the mass of water transported3.6 pressure headtensiomet
40、er headsum of the matric and pneumatic headsNOTE The pneumatic head is assumed to be zero for the purposes of this method. On this basis, the pressure head equalsthe matric head.3.7 hydraulic headsum of the matric, pneumatic and gravitational heads4 Symbolsheight, in centimetres;pneumatic head, in c
41、entimetres;hydraulic head , in centimetres;gravitational head, in centimetres;matric head, in centimetres;Kv hhv = Khhahahh= ha+hg+hmhghmBS EN ISO 11275:2014 ISO 11275:2004ISO 72114002:5)E( ISO 4002 r llAithgs reservde 3pressure head = tensiometer head , in centimetres;compartment and tensiometer in
42、dex;time and measurement interval index;compartment index;unsaturated hydraulic conductivity, in centimetres per day ( );mass, in kilograms;mass of soil sample at the end of the test, in kilograms;time, in days ( )soil water volume flux density, in centimetres per day ( );volume, in cubic metres;ver
43、tical coordinate, in centimetres;water content as volume fraction;density of water, in kilograms per cubic metre.5 PrincipleUndisturbed samples of soil are taken from the field in accordance with ISO 10381-1. Each soil sample is firstwetted to near saturation in the laboratory. Then the sample is al
44、lowed to dry by evaporation from the topsurface; at known times during this period, pressure heads are measured at different depths in the sample usingtensiometers, and the mass of the sample is measured. These measurements are continued until air enters anyof the tensiometers. This can take a few d
45、ays to two weeks depending on the type of soil. At the end of the test,after completing these measurements, the sample is dried and weighed, and its water content is calculated foreach of the measurement times.The sample is considered as two or more compartments (sub-samples), one for each tensiomet
46、er. For each ofthe measurement times, the water content of each compartment is calculated from the water content of thewhole sample and the tensiometer readings. The soil water-retention characteristic and the unsaturatedhydraulic conductivity are calculated from these data using an adaptation1of Wi
47、nds evaporation method2.The method treats the soil sample as being homogeneous in its hydraulic properties and assumesone-dimensional flow.6 Apparatus6.1 Equipment for sampling undisturbed soil.Usually metal or plastic sleeves of known dimensions are used, together with equipment to push the sleeves
48、into the soil. Usually the sampling sleeves are used to retain the sample throughout the test, and therefore it isnecessary to pre-drill holes for the tensiometers. The dimensions of the soil samples are dependent on the soiltype and the purpose of the investigation. The height of a sample shall be
49、less than or equal to its diameter, toprevent the acquisition of redundant data. In most cases a height of and a diameter of are suitablefor stone-free soils.The height shall be large enough to accommodate 2 to 4 tensiometers. However, larger heights delay the dryingof the lower compartments unduly, so that the determination may take too long, and may require an increase inthe number of measurement times. The ratio of the diameter to the height should be just above unity, e.g. 10:8,to provide
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1