Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1949 A piezometer method of measuring soil permeability and application of permeability data to a drainage problem James Nicholas Luthin Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Agriculture Commons, and the Soil Science Commons Recommended Citation Luthin, James Nicholas, "A piezometer method of measuring soil permeability and application of permeability data to a drainage problem " (1949). Retrospective Theses and Dissertations. 14091. https://lib.dr.iastate.edu/rtd/14091 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. NOTE TO USERS This reproduction is the best copy available. UMI A PIEZOMETER METHOD OP MEASURIIG SOIL PKRMEABILITY AID APPLIGATIOI OF PERMEABILITY DATA TO A DRAIIAGfi PROBLEM by James Micholas LutMa A fliesis Submitted to the Graduate Paeiilty for the Degree of DOCTOR OF PHILOSOPHY Ma^or Subject; Soils Approved; Signature was redacted for privacy. Signature was redacted for privacy. Head of Major Department Signature was redacted for privacy. Dean of 'Graduate Ooliege Iowa State College 1949 UMI Number: DP13349 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. UMI UMI Microform DP13349 Copyright 2005 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 S59f L317P -ii- fABLl OF COITEHTS Page I. IlfRODUCTIOI 1 II. RE?IEf OF LITSRAfURE 4 A. Darcy's Law 4 B. Equation of Flow 7 0. PerBieability Units 9 D. Methods of Measurement 10 1. Laboratory metliods 11 a. The disturbed sample 11 b. The undisturbed sample 11 2. Indirect methods . 12 3. Field methods 12 a. Unlined wells 12 b. Lined wells 13 e. tracers 14 S. Factors Affecting Soil Permeability 15 1. Entrapped air 15 2. Microorganisms 17 3. Salts 20 4. Temperature 20 F. Solution of Flow Problems 21 1. Analytical methods 21 a. Bapuit-Forchheimer theory 21 b. Kirkhaai-Gardnex approach . 25 2. Graphical methods of Dachler, Caaagrande, and Forehheiaer 26 3. The hodograph 27 4. Membrane analogue 28 5. llectrical analogue 29 lumerical methods 31 T "^0 40 -iii- Page III. THl PROBLIM 36 A. Piezometer Method for Measuring Soil PeriaeaMlity , . 36 1. Field procedure 36 2. Field tests . 40 3. Laboratory procedure ..... 45 4. Results of field tests .......... 50 5. Laboratory results 68 B. Application of Permeability Data to a Drainage Problea 73 1. Procedure 74 a. Draimage of soil with uniform perraeabillty ............. 77 b, Dralmge of soil with non-uniforw permeability 84 IV. GONGLUSIOIS AID SUMMAET 96 ¥. LITSIATURI OlfED 97 ¥1. ACIIOfLED^ffilT .103 -i¥- LIST OF TABLES xao. Page 1 Relation of Preesmre to Flow Through Glay- SeelhMai (60). 5 2 Field Test Data 51 3 Field Tftst Data 52 4 Field Test D®.ta 53 5 Field Test Bata 54 6 Field Test Data 56 7 Field Test Data 57 8 Field Test Data 59 9 Field Test Data 61 10 Field Test Data 62 11 Field Test Data 63 13 Results of luraerieal Analysis 94 -V- LIST OF FiaURlS Fig. Page 1 Illustrating Darcy*e Law. Gardner (38). 6 8 Changes in Peraieability of Soils During Long Submergence. Allison (l), 18 3 PermeaMlity-fime Curves for Hanford Loa® Under Prolonged Submergence. Allison (l). 18 4 Dupuit-Forchlieimer Theory of Soil Drainage. 24 5 Points on let 34 6 Relaxation Pattern. 34 7 Piezometer Method of Measurement of Permeability. 37 8 Installing the Piezometer. 37 9 Flushing out the Piezometer. 39 10 Applying Suction to the Piezometer. Upper Stopper is for a 2-lnch Piezometer. 39 11 Measuring Water Elevation with Reel-Type Electric Probe 44 12 Removing a l-inch Piezometer with Veihmeyer Soil Tube Jack. 44 13 Cirmiit for Location of Equipotential Surfaces. 47 frevert (27). 14 Circuit for Determination of A-function* Frevert (27) 47 15 Plot of Field Data to Show Linear Relationship Between In(d-y) and Time t. 48 16 Variatioa of A-funotion with Diameter of Cavity for a 4-inch Long Cavity (For Values of s and d See Text). 69 17 Variation of A-function with Length of Cavity for a 1-inch Diameter Cavity (For Values of s and d See Text). 69 -•ri- Fig. Page 18 fariation of A-fuactioii ?dth. s, for a Cavity 4- iaehes leag and l-iach in Maaeter. 71 19 Iqiiipotential Surfaces for a Piezometer Cavity. 71 20 Sxample of Mtbaiaim Proeedure, 75 21 Iquipoteatial Plots for Gase of iDralnag© of Uniform Soil. S©« Text for Details. 80 22 Point l€ar a Gurved Boundary. 81 23 Point on an Interface.- 86 24 Point at Upper Oorner. See Text. 89 25 Point at Lower Oorn®r, S@e Text. 89 26 Iquipottntial Plot for Drainage of a Two-layered Soil. 91 27 Icpipotential Plot for Drainage of a Two-layered Soil. 93 28 fiquipotential Garves for Drainage of a Two-layered Soil 93 I. IITROOTGTIOir It has long toe®n recognized that soil permeability is an iBEportant factor in land management, soil conservation and land drainage. Muoh work has been dxjne on methods of measuring soil permeability and various sehemes have been devised to apply the information to the design of drainage systems, dams and other engineering structures. In general, the measurement of soil permeability has con­ sisted of taking a sample of soil from the field into the labo­ ratory in either a disturbed or an undisturbed state, passing water through the sample, and determining its permeability by use of suitable equations. Such methods of permeability meas­ urement have been unsatisfactory for many reasons. Recently several faethods of determining soil permeability in the field have been proposed. In 1936 Hooghoudt augered out a hole in the soil below the water table and observed the rate of rise of water in the hole. By means of approxiLiate formu­ las he was able to calculate the soil permeability. Kirkham and Van Bavel pointed out certain defects in Hooghoudt's formu­ la and derived a more exact equation based on a solution of Laplace's equation. They tried out the method \?ith success on several Iowa soils. In 1945, Kirkham proposed a field method of measuring soil permeability x'yhich consisted of driving pipes into the -2- soil below a water table and meaiuring the outflow of water frotB the pipe® into the soil. This proposed method was tried out by Fre^ert and Kirfchaa, They found that it was necessary to remote the soil from the interior of the pipe and they also noted that a lauoh laore aecurate measure of the permeability was obtained by permitting the water to flow into the pipe from the soil rather than using the outward flow from the pipe into the soil. Because driving the pipes into the soil compresaed the soil, they had to use pipes of large diaaeter (8 inches). The depths to which the soil permeability could be measured were lifflited to 36 inches because of the equipment used, and special tools were needed to remove the pipes from the ground. the preceding field methods have in common certain ad­ vantages over any laboratory methods which have been proposed. First, the soil permeability is measured in situ; second, soil water is itself used for the measurement; and third, root holes, worm holes, and rocks have a negligible effect on the deter­ mination. There are, however, certain limitations to these field aethods. Both of them are limited to shallow depths below the soil surface and the auger hole method, as it gives a sort of average permeability over the length of the auger hole, will not Indicate the permeability of specific layers or horizons. To overcome the limitations of the above methods, a new procedure, utilizing pipes of small diameter (piezometers). -•o«» has been developed. Tiie method consists basically in measuring the ratt of flow into a canity at the base of an emptied pie- ^offleter. Advantages of the method are (l) the permeability can be measured to great depths, (2) the permeability of any layer in the soil can be measured, (3) the method is quick, acciirate and simple, fhe deirelop»ent of this method, \i^ich includes use of a three-dimensloiial electric analogue of the groundwater problem., constitutes two parts of t&ls thesis. Kirkhaa has solTed the problem of steady-state flow into tile drains in a uniform soil but there is no general solution that will handle all of the complex Tarlations found in natural soil. Similar types of problems are encountered in the fields of heat flow, electricity, and hydrodynamics and various in­ vestigators have developed numerical methods of obtaining ap­ proximate solutions to any desired degree of accuracy. Because of the similarity of these types of problems, it is evident that numerical method® qbm also be applied to problems of land drainage.