UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Soil tillage studies with model plane chisels. Strong, Chester Ray 1971

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1971_A6_7 S77.pdf [ 3.28MB ]
Metadata
JSON: 831-1.0101931.json
JSON-LD: 831-1.0101931-ld.json
RDF/XML (Pretty): 831-1.0101931-rdf.xml
RDF/JSON: 831-1.0101931-rdf.json
Turtle: 831-1.0101931-turtle.txt
N-Triples: 831-1.0101931-rdf-ntriples.txt
Original Record: 831-1.0101931-source.json
Full Text
831-1.0101931-fulltext.txt
Citation
831-1.0101931.ris

Full Text

SOIL TILLAGE STUDIES WITH MODEL PLANE CHISELS BY CHESTER RAY STRONG B.S.A., U n i v e r s i t y o f B r i t i s h Columbia, 1966  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n the Department of A g r i c u l t u r a l Mechanics  We accept t h i s t h e s i s as conforming t o the r e q u i r e d  THE UNIVERSITY OF BRITISH COLUMBIA May, 1971  standard  In  presenting  this  an a d v a n c e d  degree  the  shall  I  Library  f u r t h e r agree  for  scholarly  by h i s of  thesis at  the U n i v e r s i t y  make  that  it  written  thesis  purposes  for  may  is  financial  of  of  Columbia,  British  available  AGRICULTURAL  The U n i v e r s i t y o f B r i t i s h V a n c o u v e r 8, C a n a d a  April  14, 1971.  for  for extensive  be g r a n t e d  It  fulfilment  by  understood  gain  shall  that  not  MECHANICS  Columbia  the  requirements 1 agree  r e f e r e n c e and copying  t h e Head o f  permission.  Department o f  Date  freely  permission  representatives.  this  in p a r t i a l  of  or  that  study.  this  thesis  my D e p a r t m e n t  copying  for  or  publication  be a l l o w e d w i t h o u t  my  ABSTRACT  The p h y s i c a l c h a r a c t e r i s t i c s o f p a r t i c l e s i z e b u t i o n , c o m p a c t a b i l i t y and p l a s t i c i t y c l a y were  distri-  o f Ottawa sand and Haney  determined. D i r e c t shear t e s t s were used t o r e l a t e dry bulk  d e n s i t y , s o i l water content and normal p r e s s u r e t o the  shear  s t r e n g t h o f Ottawa sand and Haney c l a y . The  s t a t i c and k i n e t i c values o f s o i l - m e t a l  were determined  f o r each o f three c h i s e l shaped t i l l a g e  w i t h Ottawa sand and Haney c l a y .  The  friction  machines  values were then  r e l a t e d t o normal p r e s s u r e , a r e a o f c o n t a c t and s o i l content f o r each  friction  water  soil.  T i l l a g e s t u d i e s were conducted  and the f o r c e s r e s u l t i n g  from s o i l - m a c h i n e i n t e r a c t i o n were measured.  For each  soil,  these f o r c e s were r e l a t e d t o s o i l water c o n t e n t , dry bulk d e n s i t y , machine width and machine v e l o c i t y . The accordance ratios. equations of  s o i l and  chisel  v a r i a b l e s were combined i n  with the Buckingham IT theorem t o form  dimensionless  These d i m e n s i o n l e s s r a t i o s were combined to f o r use i n model-prototype  these p r e d i c t i o n s was  predictions.  form  The  accuracy  found t o vary w i t h s o i l water content, -  dry bulk d e n s i t y and machine v e l o c i t y . Since a l l measurements recorded d u r i n g the course o f t h i s study were analyzed by s t a t i s t i c a l  procedures, the  equations do not r e p r e s e n t b a s i c p h y s i c a l r e l a t i o n s h i p s .  resulting Caution  should t h e r e f o r e be used i f these equations are t o be a p p l i e d t o values beyond the range of values analyzed i n t h i s r e p o r t .  -  11  TABLE OF CONTENTS PAGE 1  INTRODUCTION Statement o f the problem  1  Study o b j e c t i v e s  2  Project  3  outline  5  REVIEW OF THE LITERATURE Soil  5  t e s t i n g procedures  Soil-tool interactions  7  Tillage tool similitude  8  Tillage tool characteristics  9 11  EXPERIMENTAL METHODS Soil  testing  11  Particle size analysis  11  Plasticity  11  tests  11  Shear t e s t i n g  12  Soil-chisel interface  12  Soil-metal f r i c t i o n T i l l a g e t e s t i n g and equipment  used  13  Equipment  13  Instrumentation  13  Tillage tools  14  Soil  16  variables  ANALYTICAL PROCEDURES  17  Shear s t r e n g t h  17  Soil-metal f r i c t i o n  17  T i l l a g e analysis  18  - iii  -  PAGE  RESULTS AND DISCUSSION  24  S o i l physical properties  24  Soil-chisel interaction  26  T i l l a g e forces  27  Direct relationships  27  Dimensionless equations  30  SUMMARY AND CONCLUSIONS  ,  53  SUGGESTIONS FOR FURTHER WORK  54  LIST OF REFERENCES  55  APPENDICES A.  Tranducer p l a n  58  B.  Amplifier  61  C.  C o r r e l a t i o n matrices f o r s o i l strength test  shear  64  D.  C o r r e l a t i o n matrices f o r soil-metal f r i c t i o n tests  66  E.  C o r r e l a t i o n matrices f o r t i l l a g e t e s t s  68  construction  - ivLIST OF TABLES  Variables  and corresponding  dimensions'  Comparison o f s o i l p h y s i c a l c h a r a c t e r i s t i c s I n t e r n a l angles o f f r i c t i o n  f o r Ottawa sand  Reaction f o r c e s f o r Ottawa sand when v e l o c i t y i s v a r i e d and B = 0.057 l b / i n and W = 1.99% 3  Reaction f o r c e s f o r Ottawa sand when water content i s v a r i e d and B = 0.054 l b / i n and V = 10.72 i n / s e c 3  R e a c t i o n f o r c e s f o r Ottawa sand when dry bulk d e n s i t y i s v a r i e d and W = 1.99% and V = 10.72 i n / s e c Reaction f o r c e s f o r Haney c l a y when v e l o c i t y i s v a r i e d and B = 0.04 7 lb/-in" and W = 8.6 8% 3  Reaction f o r c e s f o r Haney c l a y when water content i s v a r i e d and B = 0.045 l b / i n and V = 10.72 i n / s e c 3  Reaction f o r c e s f o r Haney c l a y when dry bulk d e n s i t y i s v a r i e d and W = 8.68% and V = 10.72 in/sec C o r r e l a t i o n matrix f o r d i r e c t shear t e s t s f o r Ottawa sand C o r r e l a t i o n matrix f o r d i r e c t shear t e s t s f o r Haney c l a y C o r r e l a t i o n matrix f o r s o i l - m e t a l t e s t s f o r Ottawa sand  friction  C o r r e l a t i o n matrix f o r s o i l - m e t a l t e s t s f o r Haney c l a y  friction  C o r r e l a t i o n matrix f o r t i l l a g e - t e s t s f o r Ottawa sand C o r r e l a t i o n matrix f o r t i l l a g e Haney c l a y .  tests f o r  -  V -  LIST OF FIGURES FIGURE  TITLE  1  P a r t i c l e s i z e d i s t r i b u t i o n f o r Ottawa sand  2  P a r t i c l e s i z e d i s t r i b u t i o n f o r Haney  3  R e s u l t s o f standard Ottawa sand  Proctor test f o r  4  R e s u l t s o f standard Haney c l a y  Proctor  5  Ottawa sand. A c t u a l d r a f t f o r c e v s . value computed from Equation [11]  6  Haney c l a y . A c t u a l d r a f t f o r c e v s . value computed from Equation [14]  7  Comparison o f p r e d i c t e d d r a f t f o r c e s f o r 2.25 i n c h wide c h i s e l i n Ottawa sand when v e l o c i t y i s v a r i e d and B = 0.057 l b / i n and W = 1.99%  clay  test f o r  3  8  9  10  Comparison o f p r e d i c t e d d r a f t f o r c e s f o r 2.25 i n c h wide c h i s e l i n Ottawa sand when water content i s v a r i e d and B = 0.054 l b / i n and V = 10.7 2 i n / s e c Comparison o f p r e d i c t e d d r a f t f o r c e s f o r 2.25 i n c h wide c h i s e l i n Ottawa sand when dry bulk d e n s i t y i s v a r i e d and W = 1.99% and V = 10.72 i n / s e c Comparison o f p r e d i c t e d d r a f t f o r c e s f o r 2.2 5 i n c h wide c h i s e l i n Haney c l a y when v e l o c i t y i s v a r i e d and B = 0.048 l b / i n and W = 8.68% 3  11  Comparison o f p r e d i c t e d d r a f t f o r c e s f o r 2.25 i n c h wide c h i s e l i n Haney c l a y when water content i s v a r i e d and B = 0.045 l b / i n and V = 10.72 i n / s e c  12  Comparison o f p r e d i c t e d d r a f t f o r c e s f o r 2.2 5 i n c h wide c h i s e l i n Haney c l a y when dry bulk d e n s i t y i s v a r i e d and W = 8.6 8% and V = 10.72 i n / s e c  13  Computed vs a c t u a l d r a f t f o r c e f o r 0.75 i n c h wide c h i s e l i n Ottawa sand  3  - vi -  LIST OF FIGURES CONTINUED FIGURE  TITLE  PAGE  m  Computed vs a c t u a l d r a f t f o r c e f o r 1.50 i n c h wide c h i s e l i n Ottawa sand  48  15  Computed vs a c t u a l d r a f t f o r c e f o r 2.2 5 i n c h wide c h i s e l i n Ottawa sand  49  16  A c t u a l d r a f t f o r c e vs value computed by General (G) Dimensionless Equation f o r Ottawa sand  49  17  Computed vs a c t u a l d r a f t f o r c e f o r 0.75 i n c h wide c h i s e l i n Ottawa sand  50  18  Computed vs a c t u a l d r a f t f o r c e f o r 1.50 i n c h wide c h i s e l i n Ottawa sand  50  Computed vs a c t u a l d r a f t f o r c e f o r 2.2 5 i n c h wide c h i s e l i n Haney c l a y  51  20  A c t u a l d r a f t f o r c e vs value computed by General (G) Dimensionless Equation f o r Haney c l a y  51  Al  Transducer p l a n with s t r a i n gauge l o c a t i o n s  59  A2  Wheatstone b r i d g e c o n f i g u r a t i o n s and moments to be measured  50  Bl  Schematic diagram o f s t r a i n gauge a m p l i f i e r s  19  '  f o r forces  62  ST OF NOMENCLATURE ABBREVIATIONS AND DEFINITIONS Angle of i n t e r n a l f r a c t i o n -- angle between Mohr f a i l u r e envelope and h o r i z o n t a l a x i s . s o i l dry bulk d e n s i t y •-- weight o f oven d r i e d per u n i t volume ( l b / i n ) .  soil  3  maximum dry bulk d e n s i t y Proctor test ( l b / f t ) .  o b t a i n e d with standard  3  cohesive s t r e n g t h — s o i l shear s t r e n g t h normal s t r e s s ( l b / i n ^ ) .  at zero  c o e f f i c i e n t o f u n i f o r m i t y — i n d i c a t e s slope p a r t i c l e s i z e d i s t r i b u t i o n c u r v e , determined D  of by  60 1CT /D  diameter at which 10% of the s m a l l e r diameter p a r t i c l e s .  sample i s composed o f  diameter at which 60% o f the s m a l l e r diameter p a r t i c l e s .  sample i s composed o f  s o i l v o i d r a t i o -- r a t i o of volume of v o i d space t o volume of s o i l s o l i d s i n a given s o i l sample. d r a f t f o r c e -- h o r i z o n t a l r e a c t i o n f o r c e along o f c h i s e l movement.  axis  v e r t i c a l f o r c e - - v e r t i c a l r e a c t i o n f o r c e caused chisel action.  by  k i n e t i c f r i c t i o n -- r e s i s t a n c e to motion over s o i l metal i n t e r f a c e while motion i s o c c u r r i n g at a uniform r a t e . Lower A t t e r b e r g l i m i t -- minimum water content i n percent at which s o i l e x h i b i t s p l a s t i c i t y . Moment about the h o r i z o n t a l a x i s which passes at r i g h t angle t o d i r e c t i o n of c h i s e l movement. machine s c a l e f a c t o r -- r a t i o between p r o t o t y p e machine s i z e and model machine s i z e . normal p r e s s u r e -- the normal s t r e s s a c t i n g at r i g h t angles to f a i l u r e s u r f a c e i n s o i l shear t e s t or soil-metal f r i c t i o n . p l a s t i c i t y index -- the water content d i f f e r e n c e between upper and lower p l a s t i c l i m i t s .  - viii -  peak shear s t r e s s -- the maximum shear s t r e s s value as determined from shear s t r e s s - d e f o r m a t i o n curve. r e s u l t a n t f o r c e -- maximum f o r c e r e a c t i o n t o s o i l chisel interaction. s t a t i c f r i c t i o n -- r e s i s t a n c e t o motion over s o i l metal i n t e r f a c e when motion i s imminent. steady shear s t r e s s — t h a t value o f s o i l shear s t r e n g t h where shear s t r e n g t h remains r e l a t i v e l y constant i n s p i t e o f i n c r e a s i n g deformation. C h i s e l area — surface.  c h i s e l width times l e n g t h below  soil  upper A t t e r b e r g l i m i t -- the maximum s o i l water content i n p e r c e n t a t which a s o i l sample e x h i b i t s plasticity. machine v e l o c i t y -- v e l o c i t y i n i n / s e c a t which the c h i s e l b e i n g s t u d i e d passes through a s o i l mass. s o i l water content -- the weight o f water p e r u n i t weight o f d r y s o i l expressed on a percentage b a s i s . the water content a t which maximum d r y bulk d e n s i t y o c c u r s f o r standard P r a e t o r t e s t .  -••ix -  ACKNOWLEDGEMENTS  The w r i t e r wishes t o express h i s s i n c e r e g r a t i t u d e t o P r o f e s s o r L.M. S t a l e y f o r a s s i s t a n c e and guidance i n cond u c t i n g t h i s study. The encouragement and help rendered by Dr. J . d e V r i e s , Dr. R. Campanella  and Dr. E, Nyborg i s g r e a t l y  appreciated. The w r i t e r a l s o wishes t o thank C h i e f  Technician  Mr. W. Gleave and a s s i s t a n t Mr. H. Pehlke f o r h e l p i n developing  the equipment  and i n s t r u m e n t a t i o n  used i n t h i s  study. F i n a n c i a l support f o r t h i s i n v e s t i g a t i o n was p r o v i d e d by t h e N a t i o n a l Research C o u n c i l o f Canada, through Grant number A-1915.  INTRODUCTION Statement o f the problem While s o i l for  c u l t i v a t i o n machines helped form a b a s i s  a g r i c u l t u r e , man has been unable to determine a complete  mathematical r e l a t i o n s h i p i n v o l v e d the  soil.  between these machines and  Consequently he has been unable t o do q u a n t i t a t i v e  design e i t h e r f o r m i n i m i z i n g the f o r c e s or f o r c r e a t i n g  a specific soil  and e n e r g i e s  condition.  involved  In f a c t , t r i a l and  e r r o r methods have been merely expanded i n o r d e r t o develop increasingly reaction  complex t i l l a g e  forces  t o o l s without knowing e i t h e r t h e i r  o r t h e i r e f f e c t s i n advance.  In most i n s t a n c e s  where engineers o r o t h e r s c i e n t i s t s have attempted t o develop a quantitative by  s o i l - m a c h i n e r e l a t i o n s h i p , they have been prompti  a need t o develop an immediate, s i n g l e complex t i l l a g e  tool  (such as an advanced mouldboard plow) o r the study has been r e s t r i c t e d t o an extremely s m a l l p a r t o f the o v e r a l l p i c t u r e . One must note t h a t while e a r l y workers d i d not have access t o modern, h i g h speed e l e c t r o n i c computers, t h i s type o f equipment has  been used only t o a l i m i t e d extent f o r data a n a l y s i s i n  many r e c e n t  projects.  F o l l o w i n g an o b s e r v a t i o n o f the almost complete of progress i n attempts t o understand s o i l - m a c h i n e t h i s p r o j e c t was designed so t h a t s o i l physical  lack  interactions  the i n d i v i d u a l e f f e c t s o f  c h a r a c t e r i s t i c s , s o i l strength  properties,  machine s i z e and o p e r a t i n g v a r i a b l e s  might be s t u d i e d and  analyzed i n an independent, o r d e r l y  fashion.  soil  Study O b j e c t i v e s 1)  To s e l e c t  two b a s i c  other exhibiting their physical  s o i l s , one being c o h e s i o n l e s s and the cohesive p r o p e r t i e s and t o determine  characteristics  of particle size  distri-  b u t i o n , c o m p a c t a b i l i t y and upper and lower A t t e r b e r g limits. 2)  To determine the e f f e c t s o f dry bulk d e n s i t y , s o i l water content and a p p l i e d s t r e n g t h o f each  3)  normal p r e s s u r e on the shear  soil.  To determine the magnitude and c h a r a c t e r i s t i c s and  of static  k i n e t i c f r i c t i o n when movement occurs between the  s o i l - c h i s e l interface interface  and to determine the e f f e c t s o f  area, applied  normal p r e s s u r e , s o i l water  content and dry bulk d e n s i t y on the f r i c t i o n  forces f o r  each c h i s e l and s o i l t o be s t u d i e d . 4)  To determine f o r each s o i l the e f f e c t s o f dry bulk  density.  water c o n t e n t , c h i s e l width and v e l o c i t y on the r e a c t i o n f o r c e s f o r f l a t , c h i s e l shaped machines i n c l i n e d t o e n t e r the s o i l a t 45 degrees t o the d i r e c t i o n o f motion. 5)  To use the Buckingham TT theorem f o r d e v e l o p i n g a s e r i e s o f dimensionless r a t i o s soil,  involving  a l l measured and c a l c u l a t e d  s o i l - c h i s e l and c h i s e l v a r i a b l e s  regression analysis,  t o develop p r e d i c t i o n  capable o f c o r r e l a t i n g s o i l - c h i s e l reaction  and then by equations  these dimensionless r a t i o s so that  f o r c e s are i n d i c a t e d .  3.  Project outline In accordance with the p r e v i o u s l y s t a t e d o b j e c t i v e s , Ottawa sand and Haney c l a y were s e l e c t e d as s o i l s with the q u a l i t i e s desired f o r the scope of t h i s p r o j e c t .  Both s o i l s  were subjected to mechanical a n a l y t i c a l procedures i n order to determine t h e i r p a r t i c l e s i z e d i s t r i b u t i o n and Atterberg  limits.  Both s o i l s were then subjected to standard Proctor t e s t s i n order to develop a sound basis f o r understanding the e f f e c t s of s o i l water content and dry bulk density on input energy r e l a t i o n s h i p s f o r these s o i l s .  D i r e c t shear t e s t s were then  c a r r i e d out on each s o i l and the s o i l shear strength r e l a t e d to the f o l l o w i n g v a r i a b l e s ;  was  normal l o a d , s o i l water  content and dry bulk density. Three c h i s e l widths; were studied i n f r i c t i o n s o i l surfaces.  0.75,  1.50  and 2.25  inches  t e s t s by moving each over prepared  The r e a c t i o n forces were measured to determine  the s o i l - m e t a l f r i c t i o n  involved.  For each c h i s e l and f o r  each s o i l , the normal l o a d , s o i l water content and dry bulk density were v a r i e d so that t h e i r e f f e c t s on the friction  soil-machine  forces might be developed on a q u a n t i t a t i v e b a s i s . The f i n a l p o r t i o n of the study was  then c a r r i e d out  -  by moving each c h i s e l at various v e l o c i t i e s through a l a r g e sample of each s o i l .  The consequent r e a c t i o n forces were  measured as s o i l water content and dry bulk density were v a r i e d under measured c o n d i t i o n s .  These forces were then r e l a t e d to  d i r e c t l y measurable s o i l and c h i s e l v a r i a b l e s as w e l l as to  '  t h e c o m p o s i t e v a r i a b l e s .of s o i l s h e a r s t r e n g t h friction.  and  soil-metal  h.  5. REVIEW OF  LITERATURE  S o i l t e s t i n g procedures Most o f the accepted t e s t procedures f o r d e t e r m i n i n g soil for  strength  parameters have e v o l v e d from t e s t i n g and p r e d i c t i n g  s t a t i c conditions.  These t e s t procedures have been d i r e c t l y  a p p l i e d t o the dynamic r e a c t i o n s  of s o i l  tillage.  With regard  to the s o i l s c o n s i d e r e d f o r t h i s p r o j e c t , Ottawa sand i s cohesionless  and i s a r e l a t i v e l y  simple p h y s i c a l medium f o r  study and p r e d i c t i o n when compared with cohesive Haney c l a y which has been d e s c r i b e d  as a v i s c o p l a s t i c m a t e r i a l ( 1 3 ) .  Lambe (15) p r o v i d e s an e x c e l l e n t b a s i c d e s c r i p t i o n o f many"of the standard s o i l t e s t i n g procedures as w e l l as d e p i c t i n g the methods o f p r e s e n t a t i o n results.  and the u s e f u l n e s s o f the t e s t  Each t e s t o u t l i n e a l s o i n c l u d e s  o f the s o i l mechanics t h e o r i e s and  e f f e c t s involved  are  varied.  and the i n t e r a c t i o n s  when s o i l parameters and/or t e s t procedures  He a l s o s t a t e s t h a t w h i l e the shear s t r e n g t h  cohesive s o i l increased,  involved  a brief description  generally  increases  the shear s t r e n g t h  of a  as the r a t e o f shear i s  o f a cohesionless  soil  varies  l e s s than 2% f o r shear r a t e s between 0.1 and 0.0006 inches p e r minute. Panwar and Siemens (19) were able  to r e l a t e  f a i l u r e energy r e l a t i o n s h i p s and shear s t r e n g t h and  dry bulk d e n s i t y  soil  t o water content  f o r a Drummer s i l t y c l a y loam s o i l .  These  r e l a t i o n s h i p s were developed from the r e s u l t s o f a s e r i e s o f d i r e c t shear t e s t s and unconfined compression t e s t s . Gill  (8) was able  t o develop a r e l a t i o n s h i p between  p r o g r e s s i v e l o s s e s of s o i l water by a s o i l sample w i t h c o r r e s ponding dry bulk d e n s i t y i n c r e a s e s and was to  consequently able  v e r i f y the e x i s t e n c e o f a shrinkage l i m i t on the b a s i s o f  quantitative  tests.  By a p p l y i n g X-ray techniques to s o i l and Persson  studies , Kitani  (14) developed procedures capable o f d i r e c t measure-  ment o f a x i a l displacement w i t h i n a s o i l  sample.  The  displace-  ment which they measured and were able t o d e s c r i b e q u a n t i t a t i v e l y was triaxial  caused by the compression  shear t e s t apparatus.  a l s o able t o r e l a t e normal lateral  of a s o i l sample by  Using t h i s technique they were  s t r e s s e s t o measured v a r i a b l e  stresses. Kim  (13) was  a l s o able to d i r e c t l y measure  soil  deformation induced by a p p l i e d s t r e s s e s by u s i n g Moire  fringe  techniques which he developed f o r cohesive s o i l s . Vomocil and C h a n c e l l o r (28) r e l a t e d the  compressive  and t e n s i l e s t r e n g t h o f remoulded samples o f Yolo s i l t Yolo s i l t y c l a y and Columbia  silt  loam,  loam t o both v o l u m e t r i c water  content and moisture r e t e n t i o n p r e s s u r e . • N i c h o l s (17) was tillage  a p i o n e e r i n the f i e l d o f s o i l  s t u d i e s and h i s s e r i e s o f a r t i c l e s e n t i t l e d  "The  Dynamic P r o p e r t i e s of S o i l s " o u t l i n e d a s e r i e s o f t e s t  results  and t h e o r i e s capable o f r e l a t i n g some o f the s o i l s t r e n g t h p r o p e r t i e s t o p h y s i c a l l y measurable Fox, e t a l . (7) determined  soil  variables.  the energy  required to  p u l v e r i z e a s o i l sample t o a d e s i r e d s t a t e and r e l a t e d  this  energy to the moisture content and sample.  They a l s o r e l a t e d s o i l  p a r t i c l e s i z e s o f the  shear s t r e n g t h  to s o i l  soil  moisture  content. Soil-tool  interactions The  i n t e r a c t i o n between a s o i l and  a machine operated  so as t o rearrange t h i s s o i l i s an extremely complex area study.  Development of any  r e l a t i o n s h i p attempting to  such i n t e r a c t i o n s must i n v o l v e understanding the and/or cumulative e f f e c t s of a l l s o i l and included  i n the  a f f e c t the  r e l a t i o n s h i p and  initial  et a l . (18) were able  s o i l condition  to the  forces  imposed by a s o i l sample".  forces  involved  and  conditions  and  The  the f o r c e s  t o o l while i t s operation  tools operating  i n conjunction  a s p e c i f i c t o o l operating  forces  could  to determine the  effects  angle of approach extent o f  and  reaction  physical  the modes o f s o i l r e a c t i o n as a  Chisholm et a_l. (5) s t u d i e d  for  variables  They measured the  tillage  l a t t e r were determined  v i s u a l l y through a g l a s s w a l l e d t i l l a g e  tillage  machine  types and  t o o l passed through a s o i l mass.  soil  individual  the manner i n which they  o f plow share shape, amount o f wear and  the  explain  interaction. Nichols  the  of  bin.  the r e l a t i o n s h i p s among  a c t i n g on an i n d i v i d u a l  i s being a f f e c t e d by  other  with i t . They determined  that  i n an a r t i f i c i a l s o i l , d r a f t  be v a r i e d by over 25%  depending on associated  the  degree  and  type o f i n t e r f e r e n c e  caused by  the  tools.  Wismer and  Luth (30)  were able to develop p r e d i c t i o n  8.  equations f o r c h i s e l s o p e r a t i n g studies  in saturated  clay s o i l s .  i n d i c a t e d a r e l a t i o n s h i p between the  strength  apparent cohesive  o f a s o i l as determined by undrained t r i a x i a l  t e s t s and  the  resistance  o f the  s o i l to the  Their  shear  i n t r u s i o n o f a cone  shaped penetrometer. Nichols involved  (17)  was  able  to r e l a t e the  in soil-metal f r i c t i o n  t o o l a r e a , the  surface  o f the  tillage  soil-tool  cases of extremely loose  s o i l conditions,  density  was  of the  soil.  He  able  phases o f s o i l - m e t a l f r i c t i o n ; and  lubrication.  The  reactions  to s o i l water c o n t e n t ,  condition  normal p r e s s u r e a p p l i e d t o the  force  tillage  t o o l , the  i n t e r f a c e and, t o the  dry  to observe f o u r  in  bulk  distinct  compression, f r i c t i o n ,  main d i s t i n g u i s h i n g f a c t o r was  adhesion soil  water c o n t e n t . Tillage tool similitude A number o f p r o j e c t s s t a n d i n g o f the  i n t e r a c t i o n s between s o i l s  have been based on the ratios.  The  designed to e v o l v e an  theories  has  been s u c c e s s f u l l y used i n f l u i d  may  to the  Buckingham IT theorem.  dimensionless  not  f i e l d o f s o i l mechanics.  has  Consequently,  procedure been the  i n manners which  i n d i c a t e t h e i r p r e c i s e e f f e c t on  tool interactions.  This  mechanics and  machine v a r i a b l e s have been t r e a t e d  o r may  tools  dimensionless r a t i o s i n v o l v e measurable parameters  are c a l c u l a t e d by the  s o i l and  tillage  o f s i m i l i t u d e and  and  applied  and  under-  specific soil-  Some i n v e s t i g a t o r s have s u c c e s s f u l l y used  t h i s procedure to develop s a t i s f a c t o r y p r e d i c t i o n equations f o r the  s p e c i f i c conditions  they were s t u d y i n g .  have not been so f o r t u n a t e .  Others, however,  A l l have been unable t o p r o v i d e  9. e x p l a n a t i o n s f o r e i t h e r success ov f a i l u r e i n terms o f s o i l or  t o o l parameters and t h e i r e f f e c t on s o i l  mechanics.  Reaves, e_t a l . ( 2 1 ) were able t o develop based  and/  similitude  p r e d i c t i o n equations f o r a v a r i e t y o f c h i s e l s o p e r a t i n g i n  an assortment  of s o i l types.  However, they have not i n c l u d e d  water content i n any o f t h e i r dimensionless r a t i o s and d i d not mention the water contents at which the s o i l s were t e s t e d . . Wang, et a l . (29) s t a t e t h a t they have equations  developed  capable o f p r e d i c t i n g d r a f t f o r c e s with  acceptable  accuracy l i m i t s under any given range o f s o i l c o n d i t i o n s by c o n d u c t i n g experiments  in a different s o i l .  They a l s o c l a i m  the a b i l i t y t o estimate d r a f t f o r c e w i t h i n a  model-prototype  s c a l e f a c t o r of 2 to 1 without h a v i n g to r e s o r t to d i s t o r t e d models.  These c o n c l u s i o n s were s t a t e d f o l l o w i n g t e s t s  con-  ducted on a s i n g l e s o i l at an unstated water c o n t e n t . U n f o r t u n a t e l y , they have deemed as unimportant  and t h e r e f o r e  have not i n d i c a t e d the extent o f the experiments  t o be  conducted  i n the d i f f e r e n t s o i l s under c o n s i d e r a t i o n . Tillage tool The has  characteristics l a c k of a v a i l a b l e q u a n t i t a t i v e design parameters  r e s u l t e d i n most t i l l a g e t o o l designs b e i n g based  and e r r o r methods and q u a l i t a t i v e o b s e r v a t i o n s . tillage  Very  on  trial  few  s t u d i e s are designed t o y i e l d d i r e c t q u a n t i t a t i v e  infor-  mation r e g a r d i n g the i n t e r a c t i o n s o f v a r i o u s t o o l parameters or  the e f f e c t s o f these i n t e r a c t i o n s on t i l l a g e  forces.  Kaufman and T o t t e n (12) have o u t l i n e d a q u a l i t a t i v e process f o r d e v e l o p i n g a s p e c i f i c mouldb.oard plow while  10. Soehne (24) has o u t l i n e d the development o f t i l l a g e i n r e l a t i o n to t i l l a g e quantitative  requirements and i n d i c a t e s that improved  knowledge might r e s u l t i n m o d i f i c a t i o n s  improvements t o t i l l a g e Carlson  tools  and  tools.-  (3) has o u t l i n e d the development o f mould-  board plows from the stages o f q u a l i t a t i v e a n a l y s i s t o the development o f a mouldboard plow from t h e o r e t i c a l knowledge.  This q u a n t i t a t i v e  quantitative  knowledge i s analyzed and  converted t o design c r i t e r i a by use o f a s p e c i a l computer program.  11EXPERIMENTAL METHODS Soil  testing  Particle size  analysis  Samples o f Ottawa sand and Haney c l a y were s u b j e c t e d to  a dry s i e v e a n a l y s i s .  passed through 0.149 a n a l y s i s was  mm  Since no p a r t i c l e s o f Ottawa sand s i e v e openings, the p a r t i c l e  deemed completed.  Haney c l a y was,  s u b j e c t e d to a Bouyoucos hydrometer Lambe (15).  size  however,  a n a l y s i s as o u t l i n e d  The r e s u l t i n g data were then p l o t t e d on  l o g a r i t h m i c graph paper and the values o f D ^ Q , Dg^  by  semi  and the  c o e f f i c i e n t o f u n i f o r m i t y were determined from these graphs. Plasticity  tests  Ottawa sand, b e i n g c o h e s i o n l e s s , was plasticity was  However, the c o h e s i v e Haney c l a y  subjected to Atterberg l i m i t  Lambe (15). plasticity Shear  testing.  not s u b j e c t e d t o  t e s t s as d e s c r i b e d by  The upper and lower A t t e r b e r g l i m i t s index were thus  soil  and  determined.  testing A major problem i n s t u d y i n g the r e l a t i o n s h i p s between  the  shear s t r e n g t h and dynamic s t r e n g t h p r o p e r t i e s o f a s o i l i s  the  s e l e c t i o n of a s u i t a b l e s o i l  shear t e s t procedure.  Other  i n v e s t i g a t o r s have noted d i f f e r e n c e s r e s u l t i n g from v a r y i n g the  t e s t procedures.  Very l i t t l e  information i s a v a i l a b l e to  r e l a t e the a c t i o n s and r e s u l t s o f these t e s t procedures to the  a c t i o n s and r e s u l t s imposed  during t i l l a g e .  Thus, v a r i o u s  t e s t procedures were s t u d i e d f o r t h e i r shear a c t i o n s and corresponding usefulness.  The  their  f a c t o r s most c o n s i d e r e d i n  s e l e c t i n g the t e s t procedure were the freedom o f s o i l  pore  water movement and the r e l a t i v e degree t o which the shear planes would be predetermined d u r i n g t i l l a g e .  failure  Consequently, the  s t r a i n - c o n t r o l l e d d i r e c t shear t e s t d e s c r i b e d by Lambe (15) was s e l e c t e d as t h i s procedure most c l o s e l y i n d i c a t e d the shear f a i l u r e behaviour d u r i n g t i l l a g e t e s t i n g w i t h plane c h i s e l s . Each s o i l was shear t e s t e d i n both compact and l o o s e c o n d i t i o n s at each o f t h r e e water c o n t e n t s .  Each o f these combinations was  a l s o s u b j e c t e d to normal p r e s s u r e o f 3.75, 9.28 and 17.53 pounds per square i n c h .  For Ottawa sand, the water contents were  0, 10.8. and 19.9 % w h i l e f o r Haney c l a y , they were 0, 16.8 and • 27.7  %.  These water contents were o b t a i n e d by c a r e f u l l y hand  mixing water with the s o i l samples soil  samples  to obtain uniformity.  were then s u b j e c t e d t o shear t e s t i n g .  The  T h i s mixing  procedure was s e l e c t e d t o maximize the s i m i l a r i t y between shear t e s t i n g and t i l l a g e t e s t i n g where the volume o f s o i l  involved  d i c t a t e s t h i s procedure be used. Soil-chisel Soil-metal  interface friction  S o i l - m e t a l f r i c t i o n was the f o r c e r e q u i r e d t o move each c h i s e l a c r o s s the s u r f a c e o f a s o i l  sample.  An I n s t r o n  t e s t e r was used t o p r o v i d e a constant r a t e o f movement and a continuous r e c o r d o f f r i c t i o n recorder.  f o r c e on an a s s o c i a t e d  chart  Each c h i s e l was t e s t e d w i t h normal loads o f 0, 0.22  2.2 and 4.4 pounds p l u s the weight o f the c h i s e l and a s s o c i a t e d brackets.  The s o i l s were t e s t e d i n both l o o s e and compact  c o n d i t i o n s f o r water contents o f 0, 10.0 Ottawa sand and 0, 10.0  and 19.2 % f o r  and 2 6.3 % f o r Haney c l a y .  13 . T i l l a g e t e s t i n g and equipment  used  Equipment A tillage  t e s t bed was designed and c o n s t r u c t e d to  p r o p e l a t i l l a g e t o o l through an e i g h t f o o t long sample  a t c o n t r o l l e d v e l o c i t i e s between zero and f i v e m i l e s  per hour.  The u n i t was powered by a one h a l f  speed c o n t r o l l e d Servo-Tek e l e c t r i c motor. was  soil  horsepower  A tillage  tool  c a r r i e d on an aluminum c a r r i a g e r i d i n g on Thomson b a l l  bushings and case hardened, p o l i s h e d s t e e l s h a f t s to minimize f r i c t i o n drag and v i b r a t i o n . Instrumentation A t r a n s d u c e r f o r measuring the f o r c e s along each o f t h r e e o r t h o g o n a l axes and the moments about each o f these axes w i t h each measurement being independent was developed f o r t h i s study. (See Appendix A ) . The b a s i c measuring u n i t s were e l e c t r i c a l s t r a i n gauges.  resistance  These gauges, each h a v i n g a r e s i s t a n c e o f  500 ohms and a gauge f a c t o r o f 2.12, were connected i n wheatstone b r i d g e c o n f i g u r a t i o n s .  Attempts were made to c o n s t r u c t  a m p l i f i e r s s u i t a b l e f o r a m p l i f y i n g the r e s u l t i n g  signals  u s i n g M o t o r o l a MC 14 39 G o p e r a t i o n a l a m p l i f i e r s as a base. (See Appendix B).  S e r i o u s and time consuming  problems,  i n c l u d i n g c r o s s t a l k between a m p l i f i e r u n i t s and d i f f i c u l t y i n i s o l a t i n g them from e l e c t r i c a l n o i s e i n the s u r r o u n d i n g area were encountered.  These problems were s o l v e d b e f o r e  d i s c o v e r i n g t h a t a t the h i g h r a t e s o f a m p l i f i c a t i o n these u n i t s l a c k e d l o n g term  stability.  required,  14. Consequently,  the output  ( v e r t i c a l f o r c e ) and M  from the t r a n s d u c e r s f o r F  (moment about Y - a x i s ) were f e d i n t o y  Brush model RD561200 a m p l i f i e r s and the s i g n a l recorded on the a s s o c i a t e d Brush model BL-202 two channel The t r a n s d u c e r output model BAM  chart recorder.  f o r d r a f t f o r c e (E^) was f e d i n t o an E l l i s  - 1' a m p l i f i e r and then recorded on a model  7100-A  Mosely c h a r t r e c o r d e r . The c h a r t speed f o r the Mosely r e c o r d e r i s p r e c i s e l y controlled.  T h e r e f o r e , the d i s t a n c e between 2 marks which  are produced on the c h a r t by the c a r r i a g e p a s s i n g microswitches  over  p r o v i d e s an a c c u r a t e i n d i c a t i o n o f machine  velocity. / The v a r i a t i o n i n angle o f approach o f a t i l l a g e  tool  a t t a c h e d t o the t r a n s d u c e r i s 0.16 degrees at the maximum design d r a f t f o r c e o f 150 pounds.  T h i s f a c t o r i s important  as the  angle o f approach f o r d i f f e r e n t s i z e d t i l l a g e t o o l s must be constant t o m a i n t a i n geometric Tillage  similarity.  tools Three widths o f plane c h i s e l s were used t o produce  s c a l e f a c t o r s s u i t a b l e f o r use i n s i m i l i t u d e with the s m a l l e s t a c t i n g as a model f o r the o t h e r two, and the i n t e r m e d i a t e s i z e a c t i n g as a model f o r the l a r g e s t . o f 1.5, 2.0 and 3.0 were s t u d i e d .  Thus, s c a l e f a c t o r s  Observations  of other  experiments (10) i n d i c a t e t h a t depth o f o p e r a t i o n and c h i s e l width have d i v e r s e e f f e c t s on t i l l a g e d r a f t f o r c e s . A l l c h i s e l s were t h e r e f o r e operated  at the same depth o f t h r e e  inches and c h i s e l area was r e l a t e d to the s c a l e f a c t o r .  15 . T h i s f a c t o r c r e a t e s d i m e n s i o n a l l y d i s t o r t e d models and adds to the d i s t o r t i o n caused by the s o i l s which a r e used machines.  for a l l  A l s o width, as a design v a r i a b l e , i s c o n t r o l l e d  by machine designers w h i l e depth, as an o p e r a t i n g v a r i a b l e , i s c o n t r o l l e d by any i n d i v i d u a l machine o p e r a t o r . In o r d e r t o maintain u n i f o r m i t y , a l l c h i s e l s were c o n s t r u c t e d from one p i e c e o f 1/8 i n c h t h i c k hot r o l l e d steel.  Each was m i l l e d t o w i t h i n 0.002 inches o f the  d e s i r e d width and then hand p o l i s h e d , with crocus c l o t h , t o a mirror f i n i s h .  The f i n a l l a p p i n g was p a r a l l e l t o the  d i r e c t i o n o f s o i l movement over the c h i s e l f a c e . l e a d i n g edge o f each t o o l was sharpened  The  t o an angle o f 30°.  Thus, a c l e a r a n c e o f 15° was formed between the c h i s e l under s u r f a c e and the s o i l . The  0.75 i n c h wide c h i s e l was operated a t 10% o f the  p o t e n t i a l speed o f the Servo-Tek motor while the 1.50 i n c h c h i s e l was operated a t 14.14% and the 2.25 i n c h c h i s e l a t 17.32%.  These values were chosen t o maintain  model-prototype  s i m i l i t u d e as the v e l o c i t i e s o f each prototype c h i s e l are determined  =  V /FT m  Vp  =  v e l o c i t y o f prototype  V  =  v e l o c i t y o f model c h i s e l  =  model-prototype  V when  by the r a t i o :  n  p  m  [1] chisel  J  Although not a requirement  scale  factor.  f o r s i m i l i t u d e based  prediction  e q u a t i o n s , each c h i s e l was operated at a l l three v e l o c i t i e s  i n order to develop a more complete understanding of v e l o c i t y as a f a c t o r a f f e c t i n g soil-machine r e a c t i o n f o r c e s . S o i l variables Each c h i s e l v a r i a b l e was t e s t e d i n both the loose and compacted s t a t e s f o r each s o i l at each of three d i f f e r e n t water contents.  For Ottawa sand, the water contents were  0, 2 and 4 percent with the dry bulk density varying between 0.0 51 and 0.0 57 pounds per cubic i n c h .  Haney c l a y was t e s t e d  at water contents of 0, 8.7 and 13.9 percent while the dry bulk density v a r i e d between 0.043 and 0.047 pounds per cubic inch.  P r i o r to each t r i a l , samples were taken f o r water  content determination and f i x e d volumes of s o i l were removed by a sampling core and weighed f o r bulk density determination.  ANALYTICAL PROCEDURES Shear s t r e n g t h During each t e s t , s t r e s s and deformation were read from d i a l gauges and recorded manually graphically.  and were then  related  Both the peak shear s t r e s s v a l u e and the steady  shear s t r e s s value were d e r i v e d from these graphs.  For both  s o i l s , each o f these values was r e l a t e d t o s o i l water content, dry bulk d e n s i t y and normal p r e s s u r e f o r each t r i a l . step was completed  This  by a n a l y z i n g these v a r i a b l e s w i t h the  m u l t i p l e l i n e a r r e g r e s s i o n and stepwise  linear regression  package a v a i l a b l e on an IBM 360/67 e l e c t r o n i c computer a t the U n i v e r s i t y o f B r i t i s h Columbia as was a l l r e g r e s s i o n a n a l y s i s f o r t h i s study.  The s i g n i f i c a n c e o f each f a c t o r ' s c o n t r i b u -  t i o n t o the r e g r e s s i o n e q u a t i o n was p r o v i d e d i n the computer p r i n t o u t during t h i s Soil-metal  analysis.  friction As f o r most f r i c t i o n s t u d i e s , both s t a t i c and k i n e t i c  friction  f o r c e s were determined.  S t a t i c f r i c t i o n i s the peak  r e s i s t a n c e t o s l i d i n g which occurs when motion i s imminent. K i n e t i c f r i c t i o n i s the r e s i s t a n c e which occurs d u r i n g movement at a r e l a t i v e l y uniform r a t e .  Both values were recorded by a  c h a r t r e c o r d e r and measured by manually  measuring the r e s u l t i n g  d e f l e c t i o n s on the c h a r t and comparing them t o p r e v i o u s calibrations.  Each f r i c t i o n f o r c e was then r e l a t e d t o s o i l  water content, dry bulk d e n s i t y , normal p r e s s u r e and c h i s e l width by m u l t i p l e l i n e a r r e g r e s s i o n and stepwise regression.  linear  18. Tillage  analysis Draft force  (F ), v e r t i c a l f o r c e  (F ) and the moment  about the h o r i z o n t a l a x i s running p a r a l l e l t o the c h i s e l (My) were c o n t i n u o u s l y  monitored on c h a r t r e c o r d e r s  e n t i r e l e n g t h o f each t r i a l .  F  and M z  from the Brush c h a r t a t 5 mm. F  face  d u r i n g the  were then read  directly  y  J  i n t e r v a l s on the c h a r t , w h i l e  was determined by measuring the d e f l e c t i o n s on the Mosely  c h a r t t o the nearest  1/100 i n c h a t 1/10 i n c h l o n g i t u d i n a l  i n t e r v a l s on the c h a r t .  The data f o r each t e s t was then  averaged f o r the d u r a t i o n o f the s p e c i f i c t r i a l and the f o r c e s converted t o pounds and the moments t o foot-pounds by comparison with previous  calibrations.  The r e s u l t a n t f o r c e  (R) and the normal pressure  (N) e x e r t e d  calculated  M u l t i p l e l i n e a r r e g r e s s i o n and  f o r each t r i a l .  on the c h i s e l were  stepwise l i n e a r r e g r e s s i o n were then used to r e l a t e each f o r c e t o the water content and dry bulk d e n s i t y o f each as w e l l as t o c h i s e l width and v e l o c i t y .  The f o r c e s were  then r e l a t e d t o the c a l c u l a t e d weight o f s o i l v e l o c i t y , shear s t r e n g t h process.  soil  disturbed,  and s o i l - m e t a l f i r c t i o n by the same  Using the Buckingham IT theorem, dimensionless  ratios,  which i n c l u d e d the v a r i a b l e s and t h e i r c o r r e s p o n d i n g dimensions as shown i n Table 1, were developed. TABLE 1 V a r i a b l e s and Corresponding Dimensions Variable Dry bulk d e n s i t y Chisel velocity Water content C h i s e l area T i l l a g e forces Shear s t r e n g t h Soil-metal f r i c t i o n Gravity  Dimensions  Symbol B V W TL R  Using B, V and TL as the r e p e a t i n g v a r i a b l e s , the f o l l o w i n g TT terms were developed. TT  1  TT„ 2  =  W  =  F  F  x  BV TL =  TT^  =  q  S BV F B V  TT 5 c  =  2  2  R  D  * BV TL ' BV TL  2  ir j  z 2  2  (S may be e i t h e r the peak o r the steady value)  (F may be e i t h e r the s t a t i c o r the k i n e t i c value)  (TL) V  1 / 2  G  2  The ^2 terms were then r e l a t e d t o the remaining TT terms by m u l t i p l e l i n e a r r e g r e s s i o n and stepwise l i n e a r r e g r e s s i o n . The  TT terms f o r each c h i s e l were f i r s t  analyzed s e p a r a t e l y so  t h a t r e g r e s s i o n equations were developed f o r each c h i s e l i n each s o i l .  The next procedure  i n v o l v e d d e t e r m i n i n g the  r e g r e s s i o n e q u a t i o n r e l a t i n g the TT terms formed  f o r a l l chisels  o p e r a t i n g a t t h e i r r e s p e c t i v e v e l o c i t i e s as determined by equation [ 1 ] .  T h i s step determined  s i m i l i t u d e i n model-prototype  the e f f e c t i v e n e s s o f  predictions f o r t i l l a g e  studies.  The r e s u l t s , f o r each e q u a t i o n , were then d i s p l a y e d i n both t a b u l a r and g r a p h i c a l form i n o r d e r to allow optimum  comparisons.  The r e s u l t s f o r each e q u a t i o n were compared g r a p h i c a l l y with the p r e d i c t e d  results.  20.  DIAMETER FIGURE 1.  (mm.)  PARTICLE SIZE DISTRIBUTION FOR OTTAWA SAND  100  o  i  0-1  1  .  I  001  .  0-001 ,  DIAMETER  .  0 0001  (mm.) r-o  FIGURE 2.  PARTICLE S I Z E DISTRIBUTION FOR HANEY  CLAY  FIGURE 3.  RESULTS OF STANDARD PROCTOR TEST FOR OTTAWA SAND.  23.  104 i  10  FIGURE 4.  15 20 25 WATER CONTENT (%)  30  RESULTS OF STANDARD PROCTOR TEST FOR HANEY CLAY.  RESULTS AND Soil physical The  DISCUSSION  properties results of tests involving  the b a s i c  physical  c h a r a c t e r i s t i c s o f Ottawa sand and Haney c l a y are d e p i c t e d i n Table 2 below. TABLE 2. Comparison o f S o i l P h y s i c a l  SOIL Ottawa sand Haney c l a y  Factor  Test Particle size analysis J  n  Characteristics  D ^ Q (mm.) , > D ~ (mm.)  0.48  0.000038  0.65  0.005  C  1. 353  m m  F I  131.58  u Compaction  Wopt ( % ) o B max(lb/ft )  Plasticity  UL LL PI  The  7.7 104.72  (%) (%)  -  d e t a i l e d r e s u l t s o f the p a r t i c l e  19.6 103.17 47.9 19.85 28.05  s i z e: a n a l y s i s may be  observed i n F i g u r e s 1 and 2 w h i l e the r e s u l t s o f the t e s t s are d e p i c t e d  i n F i g u r e s 3 and 4.  Ottawa sand were w i t h i n  A l l particle sizes f o r  the range f o r sand whereas the Haney c l a y  c o n t a i n e d 18% sand, 37% s i l t  and 45% c l a y .  For Ottawa sand, the shear s t r e n g t h to be r e l a t e d t o the s o i l v a r i a b l e s depicted  compaction  i n equations 2 and 3.  values were found  and normal p r e s s u r e as i s  PS  =  6.153 - 14.2267 E + 0.0133W + 7.9962E  2  + 0.5 84 8N SS  =  [2]  1.9113 - 4.8335E + 2.8998E  + 0.0004203W  2  2  + 0.5449N  [3]  For Haney c l a y the corresponding r e l a t i o n s h i p s were as d e p i c t e d i n equations 4 and 5. PS  =  0.9066 + 0.1701W - 0.3006E  - 0.007139W  2  2  + 0.6575N SS  =  [4]  0.6213 + 0.1720W - 0.2521E  - 0.006943W  2  2  + 0.6541N  [5] 2  when  PS  =  peak shear s t r e n g t h ( l b / i n  ) 2  SS  =  steady shear s t r e n g t h ( l b / i n  W  =  s o i l water content  E  =  void  )  (%)  ratio 2  N  =  normal p r e s s u r e ( l b / i n  )  Equations 2 t o 5 i n c l u s i v e were a l l s i g n i f i c a n t a t F-$ 0. 0002 and by comparison  with the Mohr  failure  envelope  e q u a t i o n , may  be used t o i n d i c a t e the cohesive s t r e n g t h and the angle o f i n t e r n a l f r i c t i o n o f the s o i l by S  =  C + o tan < J >  [6] 2  when  S  =  s o i l shear s t r e n g t h ( l b / i n  )  2  C  =  cohesive s t r e n g t h ( l b / i n  )  2  a  =  normal s t r e s s  <fj  =  angle o f i n t e r n a l f r i c t i o n (°)  (lb/in  )  As may be noted from equations 2 and 3, the cohesive s t r e n g t h of Ottawa sand i s very low (C -*• 0) w h i l e f o r Haney c l a y , equations 4 and 5 i n d i c a t e t h a t the cohesive s t r e n g t h i s , as  expected,  a much l a r g e r v a l u e .  i n d i c a t e that  A l s o , equations  2 to 5 i n c l u s i v e  the angles o f i n t e r n a l f r i c t i o n d e p i c t e d i n Table  3 are r e l a t i v e l y constant values f o r each  soil.  TABLE 3 Internal  F r i c t i o n Angles  Soil Ottawa  sand  Haney c l a y Soil-machine  f o r Ottawa Sand and Haney Clay  Tan F r i c t i o n Angle Peak Steady  F r i c t i o n Angle ((J)) Peak Steady  0.5848  0.5449  30°  18'  28°  36'  0.6578  0.6541  33°  20'  33°  12'  interaction  For both Ottawa sand and Haney kinetic  values of s o i l - m e t a l  clay, static  f r i c t i o n were found t o be  and related  t o c h i s e l width, normal p r e s s u r e and s o i l water c o n t e n t . These are d e s c r i b e d i n equations  relationships  SF = 0.009176 - 0.01T  7 and 8 f o r Ottawa sand  + 0.00281T  2  + 0. 2457N  [8]  KF = -0 . 001471 + 0 .003388W <• 0 .2433N Equations  9 and 10 d e s c r i b e the  [7]  corresponding r e l a t i o n s h i p s  f o r Haney c l a y SF = 0.001801 - 0.006722W + 0.00005255W  2  [9]  . + 0.3689N  [10]  KF = 0.002441 + 0.3151N when SF = KF = W  2 static  friction  kinetic friction  (lb/in (lb/in  = s o i l water content  (%)  ) 2 )  27. T  =  c h i s e l width ( i n )  N  =  2 normal p r e s s u r e ( l b / i n )  Equations 7 t o 10 i n c l u s i v e were a l l found t o be s i g n i f i c a n t at F 0.0.  The s o i l bulk d e n s i t i e s  f r i c t i o n t e s t s were conducted compression  phase d e s c r i b e d  s o i l bulk d e n s i t y ships  described  Tillage Direct  a t which the s o i l - m e t a l  included  no values i n the  by N i c h o l s (17).  Consequently,  was not a s i g n i f i c a n t f a c t o r i n the r e l a t i o n -  by equations 7 t o 10 i n c l u s i v e .  forces relationships During each t i l l a g e t e s t , the measured  resulted  forces  from the i n t e r a c t i o n s between the c h i s e l  i t s v e l o c i t y and the s o i l  conditions  involved,  a t the time o f t e s t i n g .  For Ottawa sand, these r e l a t i o n s h i p s are i n d i c a t e d by equations 11, 12 and 13. F  x  =  -175.7H"41 + 3 . 5582T + 3.6683W + 4983.5552B - 0.0819V - 0.5359W  2  F  z  =  2  =  [11]  2  -233.9427 + 4.8502T + 4.0905W + 8116.0604B + 0.0465V - 0.5715W  R  - 42580.OB  - 70650.OB  [12]  2  -275.9427 + 6.0246T + 5.4603W + 9536.4463B - 0.011V - 0.7783W  - 82590.OB  2  The c o r r e s p o n d i n g r e l a t i o n s h i p s  [13]  2  f o r Haney c l a y are d e s c r i b e d  by equations 14, 15 and 16. F  x  =  53.549 + 2.9051T + 0.1368W - 3731.8906B + 0.2295V + 0.0212W  2  F  z  =  + 56420.OB  [14]  2  158.3130 + 5.0347T + 0.2797W - 9414.6966B + 0.3920V + 0.0337W  2  + 128800.OB  2  [15]  28. R  =  158.8711 + 5.7662T + 0.3062W - 9774.0242B + 0.4536V + 0.0396W  2  when  + 136900.OB  F x  =  draft force ( l b )  F  =  v e r t i c a l force (lb)  R  =  resultant force ( l b )  T  =  c h i s e l width ( i n )  W  =  s o i l water content (%)  z  [16]  2  3  B  =  s o i l dry bulk d e n s i t y ( l b / i n )  V  =  chisel velocity  (in/sec).  The r e l a t i o n s h i p s d e s c r i b e d by equations 11 t o 16 i n c l u s i v e were a l l s i g n i f i c a n t a t F 0.0. Comparison o f equations 11 t o 13 w i t h equations 14 t o 16 i n d i c a t e s t h a t each s o i l type p r e s e n t s unique  tillage  r e l a t i o n s h i p c h a r a c t e r i s t i c s which must be r e c o g n i z e d and understood  on a q u a n t i t a t i v e b a s i s b e f o r e complete  relationships  can  be  developed.  soil  tillage  For the two s o i l s s t u d i e d ,  the e f f e c t s o f c h i s e l v e l o c i t y , s o i l water content and dry bulk d e n s i t y were almost completely o p p o s i t e .  However, the  n e g a t i v e v e l o c i t y e f f e c t a t t r i b u t e d t o Ottawa sand by these equations must be c o n s i d e r e d t o be exaggerated.  A possible  e x p l a n a t i o n f o r t h i s e f f e c t might be t h a t a s l i g h t v i b r a t i o n and c o r r e s p o n d i n g d r a f t r e d u c t i o n , may have been imparted t o the c h i s e l s o p e r a t i n g a t h i g h e r v e l o c i t i e s .  However, the  o v e r a l l e f f e c t o f c h i s e l v e l o c i t y i n d i c a t e s t h a t the shear s t r e n g t h o f c o h e s i o n l e s s s o i l s tends t o be n e g l i g i b l e w h i l e the shear s t r e n g t h o f c o h e s i v e s o i l s i s d e f i n i t e l y dependent.  rate  30 xi  0 10 20 30 C O M P U T E D DRAFT F O R C E (lb.) FIGURE 5.  OTTAWA SAND - ACTUAL DRAFT FORCE VS. VALUE COMPUTED FROM EQUATION 11.  30  0 10 20 30 C O M P U T E D DRAFT F O R C E (lb.) FIGURE 6.  HANEY CLAY - ACTUAL DRAFT FORCE VS. VALUE COMPUTED FROM EQUATION l U .  30. Attempts tillage  tp develop s a t i s f a c t o r y equations  f o r c e s to c h i s e l v e l o c i t y , s o i l - m e t a l f r i c t i o n ,  shear s t r e n g t h and weight  soil  of s o i l d i s t u r b e d were u n s u c c e s s f u l  due t o the low l e v e l of s i g n i f i c a n c e o f each factor.  relating  Consequently, no comparisons  contributing  with t h e o r e t i c a l  force-  r e a c t i o n equations as proposed by G i l l and Vanden Berg  (10)  were p o s s i b l e . Dimensionless equations Attempts tillage  have been made t o develop d i m e n s i o n l e s s  r e l a t i o n s h i p s u s i n g the cohesive s t r e n g t h p l u s the  angle o f i n t e r n a l f r i c t i o n shear s t r e n g t h v a l u e .  o f the s o i l t o d e s c r i b e the  However, cohesion and f r i c t i o n  were shown i n equations 2 to 5 i n c l u s i v e  soil angle  (by comparison  with  e q u a t i o n 6) to be determined by the s o i l and i t s c o n d i t i o n at  the time of t e s t i n g , and bear no r e l a t i o n s h i p t o  variables.  tillage  Consequently, the normal p r e s s u r e a p p l i e d t o the  f a i l u r e s u r f a c e must be known i n o r d e r f o r s o i l shear s t r e n g t h to  make a meaningful c o n t r i b u t i o n to a s o i l  ship equation.  to  relation-  S i m i l a r l y , the normal p r e s s u r e value i s  required f o r studying soil-metal f r i c t i o n tillage.  tillage  i n r e l a t i o n to s o i l  Since the c h i s e l s were i n c l i n e d a t an angle o f "45° ._  the s o i l  s u r f a c e and t h i s value i s very s i m i l a r i n  magnitude t o the angle o f the shear f a i l u r e planes during t i l l a g e ,  formed  the same equations were used t o i n d i c a t e  normal  p r e s s u r e f o r c a l c u l a t i n g both s o i l shear s t r e n g t h and soil-metal friction.  For Ottawa sand, the normal p r e s s u r e  i s i n d i c a t e d i n e q u a t i o n 17.  N  =  3.4248 - 1.1366T + 0.9807W + 0.2106T - 0.1379W  2  - 2.0957E  2  [17]  2  For Haney c l a y , normal p r e s s u r e i s i n d i c a t e d by e q u a t i o n 18. N  =  32.1408 - 2.8869T - 36.4914E + 0.00122V + 0.5836T  2  + 0.0115W  2  + 10.9012E  2  [18]  2 when  N  =  normal p r e s s u r e ( l b / i n )  T  =  c h i s e l width ( i n )  W  =  water content (%)  E  =  void  ratio.  The normal p r e s s u r e s d e r i v e d from equations 17 and 18 were i n c l u d e d i n the a p p r o p r i a t e s o i l - m e t a l f r i c t i o n and s o i l shear s t r e n g t h equations t o y i e l d the n u m e r i c a l values o f s o i l - m e t a l f r i c t i o n and s o i l test.  shear s t r e n g t h values f o r each  These v a l u e s were then i n c l u d e d i n the p r e v i o u s l y  developed d i m e n s i o n l e s s r a t i o s and r e g r e s s i o n equations developed  for tillage  reactions.  F o r Ottawa sand, the' 0.75  i n c h wide c h i s e l ' s r e a c t i o n s are d e s c r i b e d by equations 19, 20 and 21;  the 1.50 i n c h wide c h i s e l ' s r e a c t i o n s by equations  22, 23 and 24;  and the 2.25 i n c h wide c h i s e l ' s r e a c t i o n by  equations 25, 26 and 27.  When each c h i s e l i s operated i n  Ottawa sand a t i t s proper s i m i l i t u d e based v e l o c i t y (as determined by e q u a t i o n 1, the i n t e r a c t i o n s were as d e p i c t e d by equations 28, 29 and 30.  32.  F  — £ — BV*TL  = -0 . 0553 + 0.0127W + 0. 6634  + 1. 0308  BV*  [19]  BV  F  — | — BV TL  = -0.0276 + 0.0118W + 0.9189  + 1.0169 - ~ BV*  [20]  -\ BV TL  = -0.0514 + 0.0161W + 1. 1065 - ~ + 1.4871 ™ BV BV  [21]  BV*  F  — £ — BV TL  = -0. 007588 - 0. 001506W - 0. 2736 ^ BV  + 3. 0657  [22] BV  F  — \ — BV TL  = 0. 004433 + 0.00152W - 0. 1676 — BV  + 3.4876  -5-— BV TL  = -0. 0004752 + 0. 0001727W - 0. 2994 — + BV  [23] BV  9  4. 6332 — BV  [24]  F  —^ BV TL  = 0.0111 - 0.0101W - 0. 3835  + 3. 2361 BV*  [25] BV  F  — | — BV TL  = 0,043 - 0.011W - 0.3719  -^5 BV TL  = 0.0419 - 0. 0153W - 0. 5427  BV*  + 3.65  [26]  BV  + 4.9038 §LBV*  BV*  [27]  F  — £ — BV TL  = -0. 0393 + 0. 005241W + 0.4985  — ^ — BV TL  = -0.0309 + 0.008054W + 0. 7783  — BV TL  = -0.046 + 0.008841W + 0.9012  BV  BV*  BV  + 1.4391  + 1. 3964  [28]  BV  [29]  BV*  + 2.0249 ^ ~ BV  [30]  The c o r r e s p o n d i n g r e l a t i o n s h i p s f o r Haney c l a y are d e s c r i b e d by equations equations  31, 32 and 33 f o r the 0.75 i n c h wide  chisel;  34, 35 and 36 f o r the 1.50 i n c h wide c h i s e l ;  equations 37, 38 and 39 f o r the 2.25 i n c h wide c h i s e l .  and When  33.  each c h i s e l was operated i n Haney c l a y a t i t s proper s i m i l i t u d e based v e l o c i t y (as determined  by equation 1) the  i n t e r a c t i o n s were as d e p i c t e d by equations 40, 41 and 42  p  — £ — = 0.0135 - 0.00626W + 0.5038 ^ ~ + 0.5091 BV TL BV^ BV F  v  [31]  ^F  — | — = -0.0241 - 0.001027W + 0 . 0694 ^ ~ + 1.9370 BV^TL BV BV = -0.008109 - 0.004942W + 0. 3872 — + 1. 7879 £ £ y BV^ BV^ 9  BV^TL  [32] [33]  F  — — = 0.0602 - 0.005017W + 0.2557 BV^TL B\'  + 0.7783  BV  [34] Z  F  —5 = 0.0549 - 0.005742W + 0. 3453 BV TL BV  + 1.0868  [35] BV  34 . TABLE 4 C a l c u l a t e d Reaction Forces f o r Ottawa Sand when V e l o c i t y i s v a r i e d and B = 0.05 7 k b / i n and W = 1.99%. 3  C h i s e l Width (in.)  Equation Numbers  F  R  V  (lb)  (lb)  (lb)  (in/sec)  0.75  19,20,21  6 .80  8.59  10 .94  6.820  6 .44  8.55  10.73  10.725  6.09  8.51  10 .51  13.435  28 ,29 ,30  6 .91  8.68  11. 08  6 .820  22,23,24  12.11  15.25  19.25  6. 820  11.46  15.42  19 .27  10 .725  11.22  15.63  19.30  13.435  28 ,29 ,30  11.22  14.64  18.41  10 .725  19,20,21  11.70  14.83  18.89  6.820  10 .97  14. 72  18.42  10.725  10.21  14 .60  17.80  13.435  15.15  19.03  24 .45  6 .820  14.93  19 . 84  24 .85  10.725  14.58  20.50  24 .25  ' 13.435  28,29,30  15.51  21.50  26.45  13.435  22,23,24  15.90  21.05  26 .40  6.820  15 .60  21.40  26 .45  10 .725  15 .24  21.65  26.40  13.435  17.65  22.60  28.90  6.820  16.55  22.65  27.90  10 .725  15.48  22.35  27.30  13.435  ---  1.50  2.25  25,26,27  19 ,20,21  F X  z  35.  o  1  6  — 8 VELOCITY  FIGURE 7.  — 10  12  14  (in./sec.)  COMPARISON OF PREDICTED DRAFT FORCES FOR 2.2 5 INCH WIDE CHISEL IN OTTAWA SAND WHEN VELOCITY IS VARIED AND B = 0.057 l b / i n AND W = 1.99%. 3  TABLE 5 C a l c u l a t e d Reaction Forces f o r Ottawa Sand when Water Content i s v a r i e d and B = 0.0541 l b / i n and V = 10.725 i n . / s e c . 3  C h i s e l Width (in.)  Equation Numbers  F  (lb)  (lb)  (lb)  (%)  0.75  19,20,21  1.64  2.76  3.28  0  5.00  6.75  8.44  6.17  8.05  3.82  5.27  6.54  8.88  12.00  14.94  1.994  9.94  13.65  16.49  3.967  1,25  2.98  3.31  8.03  11.03  13.69  1.994  13.69  17.20  3.967  7.72  9.24  12.78  16.60  18.97  1.994  16.29  20.95  24.50  3.967  6.16  7.41  11.65  16.25  19.98  1.994  16.20  21.35  27.30  3.967  5.32  5.96  12.13  16.85  20.80  1.994  16.63  21.70  27.40  3.967  1.50  22,23,24  19,20,21  X  10.42 2.25  25,26,27  22,23,24  19,20,21  4.98  4.11  2.45  F  z  R  10.13  W  1.994 3.967 0  0  0  0  0  37.  25  20  0  1  0  FIGURE 8.  :  1 2 3 WATER CONTENT (%)  — 4  COMPARISON OF PREDICTED DRAFT FORCES FOR 2.2 5 INCH WIDE CHISEL IN OTTAWA SAND WHEN WATER CONTENT IS VARIED AND B = 0.05*4 l b / i n and V - 10.72 i n / s e c . 3  38 . TABLE  6  C a l c u l a t e d Reaction Forces f o r Ottawa Sand when Dry Bulk Density i s V a r i e d and W = 1 . 9 9 % and V = 1 0 . 7 2 i n . / s e c .  C h i s e l Width (in.)  0 . 75  1.50  (lb)  (lb/in )  4.17  5 .65  7 .06  0 .05114  5.00  6.75  8.44  0.0541  6.44  8.55  10.73  0.0573  7.85  1 0 . 5 7  13.20  0.0514  8.88  1 2 . 0 0  14.94  0.0541  11.46  1 5 . 4 2  1 9 . 2 7  0.0573  6.44  8.95  11.12  0.0514  8.03  1 1 . 0 3  13.69  0.0541  10.97  14.72  18.42  0.0573  9.61  13.45  16.58  0.0514  12.78  1 6 . 6 0  1 8 . 9 7  0.0541  1 4 . 9 3  19.84  24.85  0.0573  10.09  14.15  17.30  11.65  16.25  19.98  0.0541  15.60  21.40  26.45  0.0573  F  19  ,20,21  22 ,23,2i4  1 9 , 2 0 , 2 1  2 . 25  R  B  z (lb)  Equation Numbers  25 , 2 6  ,27  2 2 , 2 3 , 2 4  19,20  ,21  x (lb)  F  3  - .  0.0514  9.79  13.82  17.00  0.0514  1 2 . 1 3  16.85  20.80  0.0541  16.55  22.65  27.90  0.0573  39.  25  O I 0-050  :  0-052 DRY  FIGURE 9.  BULK  0-054 DENSITY  0-056  0-058  ( lb./ in? )  COMPARISON OF PREDICTED DRAFT FORCES FOR • 2.25 INCH WIDE CHISEL IN OTTAWA SAND WHEN DRY BULK DENSITY IS VARIED AND W = 1.994% AND V = 10.725 i n / s e c .  MO. R  BV TL  = 0. 0812 - 0. 007683W + ).4302  + 1. 3355  BV  F X  BV TL  = 0.0949 - 0.008653W + 0.4779  [36]  BV  - 0.0691 ^LBV*  BV  [37]  F ~ ~ 0.1157 - 0 . 0088T5W + 0 . 6063 £ ~ + 0. 0536 BV TL BV* BV*  [38]  Z  R  BV TL  = 0. 1497 - 0 . 0122W + 0 . 7722 BV*  + 0. 0008708 BV*  F — ~ — = -0. 0327 - 0. 005457W + 0. 5968 BV TL BV  + 0.319  [39]  [40]  BV  F P^ ^F — 5 — = -0. 007707 - 0. 001265W + 0. 2309 — A - + 1.4872 BV*TL BV* BV P PS 9F -A* = -0 . 0259 - 0. 004571W + 0. 5689 • — + 1.3260 ™ 7  BV TL  BV*  [41] [42]  BV  when Fx  =  d r a f t force ( l b )  Fz  =  v e r t i c a l force ( l b )  R  =  resultant  force ( l b ) 3  B  =  s o i l dry bulk density ( l b / i n )  V  =  chisel velocity  T  •=  c h i s e l width ( i n . )  L  =  c h i s e l depth ( i n . )  These r e l a t i o n s h i p s  (in/sec)  are a l l s i g n i f i c a n t at F 0.0  The dimensionless r a t i o s i n v o l v i n g g r a v i t y , steady shear s t r e s s , and  kinetic soil-metal  f r i c t i o n were not included i n equations 19  to 42 i n c l u s i v e as they made no s i g n i f i c a n t c o n t r i b u t i o n dimensionless  t o the  relationships.  The e f f e c t i v e n e s s of p r e d i c t i o n  from the equations f o r  Ottawa sand are d i s p l a y e d by Tables 4, 5 and 6 and by Figures  •41. 7, 8 and 9, w h i l e the p r e d i c t i o n s f o r Haney c l a y are d i s p l a y e d i n Tables 7, 8 and 9 and F i g u r e s 10, 11 and 12. As these graphs and t a b l e s i n d i c a t e , p r e d i c t i o n equations based  on s i m i l i t u d e may be developed  successfully at  some s o i l water content values and s o i l dry bulk d e n s i t y v a l u e s . Thus, the values o f dry bulk d e n s i t y and water content a t which t h e i r t e s t s were conducted  may p r o v i d e an e x p l a n a t i o n f o r the  success o f some o f the s t u d i e s r e f e r r e d to i n the l i s t o f references included i n this report.  At the same time the  f a i l u r e o f others i s e x p l a i n e d . Comparisons o f a c t u a l d r a f t f o r c e s with  those  p r e d i c t e d by the dimensionless equations f o r Ottawa sand a r e presented  i n F i g u r e s 13 t o 16 i n c l u s i v e w h i l e the c o r r e s p o n d i n g  comparisons f o r Haney c l a y are presented i n F i g u r e s 17 t o 2 0 inclusive.  Comparison o f these graphs with F i g u r e s 5 and 6  y i e l d s an i n d i c a t i o n t h a t the treatment a b l e c h i s e l and s o i l  o f the d i r e c t l y measur-  v a r i a b l e s i n the dimensionless  does not i n d i c a t e t h e i r t r u e e f f e c t on the s o i l relationship.  tillage  Indeed by comparing the v a r i a b l e treatment i n  the dimensionless r a t i o s with the treatment i n equations  equations  o f these  variables  11 t o 16 i n c l u s i v e , the c o n c l u s i o n i s reached  t h a t the e f f e c t s o f c h i s e l v e l o c i t y , c h i s e l width, s o i l water content and dry bulk d e n s i t y are t r e a t e d i n a completely d i s t o r t e d manner d u r i n g i n c l u s i o n i n dimensionless  ratios.  A l s o e x p l a i n e d by t h i s f a c t i s t h a t while the s i m i l i t u d e  based  p r e d i c t i o n s a r e s a t i s f a c t o r y at c e r t a i n s o i l v a r i a b l e v a l u e s , they are not f o r o t h e r s .  42 TABLE 7 C a l c u l a t e d Reaction Forces for Haney c l a y when V e l o c i t y i s V a r i e d and B = 0.04 7 l b / i n and W = 8.6 8% 3  C h i s e l Width (in.) 0.75  1.50  2.25  Equation Numbers  F F / i ^ i (lb) (lb)  31,32,33  R (lb)  V t- i \ (m/sec)  9.09  10.55  13.95  6.927  9.13  10.90  14.28  10.725  9.57  11.05  14.35  13.572  40,41,42  9.09  10.53  13.47  6.927  34,35,36  11.68  15.79  19.64  6.927  12.79  16.96  21.25  10.725  13.62  17.88  22.55  13.572  40,41,42  13.72  16.75  21.70  10.725  31,32,33  14.23  15.50  21.15  6.927  14.45  16.18  21.75  10.725  14.27  16.54  21.90  13.572  14.05  19.43  24.00  6.927  15.38  21.65  26.70  10.725  16.55  23.70  28.95  13.572  40,41,42  15.68  22.45  27.95  13.572  34,35,36  15.23  20.55  25.60  6.927  16.95  22.35 . 28.10  10.725  18.30  23.70  30.00  13.572  18.94  19.46  27.15  6.927  19.05  20,50  28.10  10.725  18.79  21.00  28.30  13.572  37,38,39  31,32 ,33  .  UJ  U  cr O Li-  -e- - e 10  <  actual  —  from  1 -50"  chisel  -e-  from 0-75"  chisel  cr  0  8  10 VELOCITY  FIGURE 10.  12  14  (in./sec.)  COMPARISON OF PREDICTED DRAFT FORCES FOR 2.2 5 INCH WIDE CHISEL IN HANEY CLAY WHEN VELOCITY IS VARIED AND B = 0.0<4 7 l b / i n AND W = 8.6 8%. 3  44. TABLE 8 C a l c u l a t e d Reaction Forces f o r Haney c l a y when Water Content i s V a r i e d and B = 0.045 l g / i n and V = 10.72 i n / s e c . 3  C h i s e l Width (in.)  Equation Numbers  0.75  31,32,33  1.50  34,35,36  31,32,33  2.25  37,38,39  34,35,36  31,32,33  (  F *  b )  (  F *  R b )  Q  b  W  )  5.71  6.66  8.80  0  7.77  8.99  11.93  8.679  9.65  12.75  15.82  13.926  7.68  9.64  12.34  10.40  13.68  17.20  8.679  12.80  18.60  23.20  13.926  7.57  7.69  10.80  11.71  12.36  17.07  8.679  15.42  19.45  24.85  13.926  10.40  13.10  16.50  12.95  18.17  22.35  8.679  15.10  21.55  26.10  13.926  9.27  11.37  14.67  13.34  17.40  21.95  8.679  18.45  24.80  30.90  13.926  8.71  7.79  11.68  0  14.95  14.77  21.05  8.679  20.70  25.45  32.70  13.926  0  0  0  .  0  45.  25  20  15 LU Ot  O UL  10  actual  LL  —*-  from  1-50"  chisel  from  0-75"  chisel  0 0  4 WATER  FIGURE 11.  8 CONTENT  12  16  (%)  COMPARISON OF PREDICTED DRAFT FORCES FOR 2.25 INCH WIDE CHISEL IN HANEY CLAY WHEN WATER CONTENT IS VARIED AND B = 0.04 5 l b / i n 3 AND V = 10.72 i n / s e c .  4  6  •  TABLE 9 C a l c u l a t e d Reaction Forces f o r Haney c l a y when Dry Bulk Density i s V a r i e d and W = 8.68% and V = 10.72 i n / s e c .  C h i s e l Width (in.)  Equation Numbers  FX  Fz  (lb)  (lb) (lb)  0 .75  31,32,33  5.87  6 . 44  7.77  8.99  11.93  0.0451  9.13  10.90  14.28  0.0469  7.14  9.24  11.67  0.0430  10.40  13.68  17.20  0.0451  12.79  16.96  21.25  0.0469  7.22  10.71  0.0430  11.71  12.36  17.07  0.0451  14.45  16.18  21.75  0.0469  13.28  16.40  0.0430  12.95  18.17  22.35  0.0451  15.38  21.65  26.70  0.0469  1.50  34,35,36  31,32,33  2.25  37,38,39  34 , 35 ,36  31,32,33  7.97  9.56  8 .47  10 . 74  R  8. 75  13 .70  3 (lb/in ) B  0. 0430  ... 0 .0430  13.34  17.40  21.95  0.0451  16.95  22.35  28.10  0.0469  7.08  11.54  0.04 30  14.95  14.77  21.05  0 .0451  19.05  20.50  28.10  0.0469  9.37  25  0 i 0-040  0-042 DRY  FIGURE 12.  BULK  0-044 DENSITY  0-046  0-048  (lb./in. ) 3  COMPARISON OF PREDICTED DRAFT FORCES FOR 2.25 INCH WIDE CHISEL IN HANEY CLAY WHEN DRY BULK DENSITY IS VARIED AND W = 8.6 8% AND V = 10.72 i n / s e c .  H8.  30  UJ  o  actual = 0 -249 «• 0 • 9 5 5 4 c o m p u t e d  §20 LL  LL <  cn Q  10  < 3  <  0  0 10 20 30 COMPUTED DRAFT F O R C E (lb.)  FIGURE 13.  COMPUTED VS. ACTUAL DRAFT FORCE FOR 0.75 INCH WIDE CHISEL IN OTTAWA SAND.  30  LU O  actual = - 0 -154 + 1 -0157 c o m p u t e d  §20 b_  f-  < cn  O  10  < ZD U <  0  0 10 20 30 COMPUTED DRAFT F O R C E (lb.)  FIGURE IH.  1  COMPUTED VS. ACTUAL DRAFT FORCE FOR 1.50 INCH WIDE CHISEL IN OTTAWA SAND.  49.  30 LU O  actual = -1 - 5 9 8 + 1 -1516 c o m p u t e d  cr  £'20 "r—  Lu <  or  a  10  <  ZD I—  o <  0  0  10 20 30 COMPUTED D R A F T F O R C E (lb.)  FIGURE 15.  COMPUTED VS. ACTUAL DRAFT FORCE FOR 2.25 INCH WIDE CHISEL IN OTTAWA SAND.  30 actual = 0 - 7 8 0 + 0 - 9 0 7 6  LU O  computed  §20 li_ LL  a  10  <  ZD I—  0  O 10 20 30 C O M P U T E D DRAFT F O R C E (lb.)  FIGURE 16.  ACTUAL DRAFT FORCE VS. VALUE COMPUTED BY GENERAL (G) EQUATION FOR OTTAWA SAND.  50.  30 LU  O rr O  actual = - 4 - 6 5 9 + 1 - 6 3 6 6  computed  20  LL  I-  u_ < cn  a  10  -J  <  ZD  t-  y  0  0  10  COMPUTED FIGURE 17.  20 DRAFT  30  F O R C E (lb.)  COMPUTED VS. ACTUAL DRAFT FORCE FOR 0.75 INCH WIDE CHISEL IN HANEY CLAY.  _ 30 J6  0  10  COMPUTED  FIGURE 18.  DRAFT  20  FORCE  30  (lb.)  COMPUTED VS. ACTUAL DRAFT FORCE FOR 1.50 INCH WIDE CHISEL IN HANEY CLAY.  51. 30  actual = 2 - 2 5 3 + 0 - 7 9 7 2 c o m p u t e d  LU U  cr 2 0  £ h-  < LL  cr a  10  < o i— u <  0  0  10  COMPUTED FIGURE 19.  20 DRAFT  FORCE  30 (lb.)  COMPUTED VS. ACTUAL DRAFT FORCE FOR 2.25 INCH WIDE CHISEL IN HANEY CLAY.  30  actual = 0 - 6 3 + 0 • 9 6 4 4 c o m p u t e d LU  g  20  O  LL  I— LL  C?  a  10  <  ZD  §  o  0 10 20 COMPUTED DRAFT F O R C E  FIGURE 20.  30 (lb.)  ACTUAL DRAFT FORCE VS. VALUE COMPUTED BY GENERAL (G) DIMENSIONLESS EQUATION FOR HANEY CLAY.  The give  d i f f e r e n t treatments o f these v a r i a b l e s  will  c l o s e n u m e r i c a l r e s u l t s at some values but not at  A careful re-evaluation  of o t h e r s t u d i e s  l e a d one t o conclude t h a t studies  was  the o j b e c t i v e  to t e s t the t h e o r i e s  the s t a t e d o b j e c t i v e  others.  a v a i l a b l e would o f most of these  of s i m i l i t u d e rather  of developing a s o i l t i l l a g e  than  mechanics.  A f u r t h e r disadvantage o f r e s t r i c k t i n g a s o i l tillage  study t o s i m i l i t u d e based models i s t h a t the e f f e c t s  of i n d i v i d u a l t o o l variables one  are not d i s t i n g u i s h a b l e  from  another. The main advantage  equations i n t i l l a g e  studies  t o the use o f d i m e n s i o n l e s s i s the p o s s i b i l i t y o f t e s t i n g  a s i n g l e model machine and then p r e d i c t i n g the r e s u l t s f o r larger prototypes.  The r e s u l t s from t h i s study  indicates  t h a t the procedure has d e f i n i t e p o t e n t i a l f o r use but f u r t h e r work so t h a t the v a r i a b l e s b e i n g s t u d i e d i n a manner which r e f l e c t s t h e i r a c t u a l e f f e c t on tillage  interactions.  are  requires treated  soil  53.  SUMMARY AND CONCLUSIONS 1)  Ottawa sand i s a c o h e s i o n l e s s s o i l w h i l e Haney c l a y is definitely  2)  cohesive.  S o i l v o i d r a t i o , s o i l water content and normal p r e s s u r e may be combined t o p r e d i c t the s o i l shear s t r e n g t h of e i t h e r Ottawa sand o r Haney c l a y .  3)  S o i l water c o n t e n t , area o f contact and normal p r e s s u r e may be combined t o p r e d i c t the s o i l - m e t a l f r i c t i o n between e i t h e r Ottawa sand o r Haney c l a y and the s o i l machines s t u d i e d .  4)  S o i l water c o n t e n t , dry bulk d e n s i t y , c h i s e l and c h i s e l v e l o c i t y may be combined t o p r e d i c t  width  soil-chisel  r e a c t i o n f o r c e s f o r the s o i l s and c h i s e l s s t u d i e d . 5)  The dimensionless  r a t i o s developed  may be combined t o  p r e d i c t s o i l - c h i s e l r e a c t i o n f o r c e s f o r s c a l e d implements. However, l a r g e d i s c r e p a n c i e s do e x i s t f o r c e r t a i n  soil  c o n d i t i o n s and the time r e q u i r e d f o r p r e l i m i n a r y t e s t i n g i s very e x t e n s i v e . 6)  Since a l l measurements recorded d u r i n g the course o f t h i s study were analyzed by s t a t i s t i c a l procedures, the r e s u l t i n g equations relationships. equations  do not r e p r e s e n t b a s i c p h y s i c a l  Caution should t h e r e f o r e be used i f these  are t o be a p p l i e d t o values beyond the range o f  values analyzed i n t h i s r e p o r t .  SUGGESTIONS FOR FURTHER WORK . The work i n i t i a t e d  i n t h i s study should be expanded  by adding an i n c r e a s e d number o f t i l l a g e s o i l types and to determine interactions.  t o o l v a r i a b l e s and  t h e i r e f f e c t s on s o i l - m a c h i n e  P o s s i b l e machine v a r i a b l e s t o study would be  depth o f o p e r a t i o n , angle o f approach  and machine shape.  The o t h e r s o i l types would add to the body o f knowledge developed t o the p o s s i b l e extend that dimensionless r a t i o s and consequently p r e d i c t i o n equations might be developed by combining  the s o i l and machine v a r i a b l e s i n such a manner  as t o i n d i c a t e t h e i r e f f e c t on the f o r c e  interactions  involved. The next step would be t o determine tillage  the e f f e c t s o f  t o o l v a r i a b l e s on the p r o d u c t i o n o f d e s i r e d  soil  conditions. An i n t e r e s t i n g note o f great merit i s t h a t equations 11 t o 16 i n c l u s i v e are i n such a form t h a t v e l o c i t y ,  chisel  width and r e a c t i o n f o r c e s are d i r e c t l y r e l a t e d i n such a form as t o i n d i c a t e p o t e n t i a l development o f t i l l a g e relationships.  energy  The consequence o f t h i s r e l a t i o n s h i p would  be a very meaningful study on t i l l a g e  cost m i n i m i z a t i o n .  LIST OF REFERENCES B a i l e y , A.C. and G.E. Vanden Berg, 1968. Y i e l d i n g by Compaction and Shear i n Unsaturated S o i l s . Trans. Amer. Soc. A g r i c . Eng. V o l . 11, No. 3, pp. 307-312. Barnes, K.K., C.W. Bockhop and H.E. McLeod, 1960. S i m i l i t u d e i n Studies of T i l l a g e Implement Forces, A g r i c u l t u r a l Engineering, V o l . U l , No. 2, pp. 32-37. Carlson, E.C., 1961. Plows and Computers. A g r i c u l t u r a l Engineering, V o l . 42, No. 6, pp. 292-296. Chancellor, W.J. and A.Y. Korayem, 1964. Mechanical Energy Balance f o r a Volume Element of S o i l During S t r a i n . A g r i c u l t u r a l Engineering Department, U n i v e r s i t y of. C a l i f o r n i a , Davis, C a l i f o r n i a . Chisholm, T.S., J.G. P o r t e r f i e l d and D.G. Batchelder, 1970 A S o i l Bin Study f o r Three-Dimensional I n t e r f e r e n c e Between F l a t P l a t e T i l l a g e Tools Operating i n an A r t i f i c i a l S o i l . Annual Meeting, Amer. Soc. A g r i c . Eng. Paper No. 70-122. Dunlop, W.H., G.E. Vanden Berg and J.G. Hendrick, 1966. A Comparison of S o i l Shear Values Obtained With Devices of D i f f e r e n t Geometrical Shapes. Trans. Amer. Soc. A g r i c . Eng., V o l . 9, No. 6, pp. 896-900. Fox, W.R., D.L. Deason and L. Wang, 1967. T i l l a g e Energy A p p l i c a t i o n s . Trans. Amer. Soc. A g r i c . Eng. V o l . 10, No. 6, pp. 843-847. G i l l , W.R., 1959. S o i l Bulk Density Changes Due to Moisture Changes i n S o i l . Trans. Amer. Soc. A g r i c . Eng.  V o l . 2, No.  1,'pp. 104-105.  G i l l , W.R., 1959. The E f f e c t s of Drying on the Mechanical Strength of Lloyd Clay. S o i l Science Society of America Proceedings, V o l . 23, No. 4, pp. 255-257. G i l l , W.R. and G.E. Vanden Berg, 1967. S o i l Dynamics i n T i l l a g e and T r a c t i o n . A g r i c u l t u r a l Research S e r v i c e , U.S. Dept. of Ag., A g r i c u l t u r e Handbook No. 316. Hendrick, J.G. and G.E. Vanden Berg, 19 61. Strength and Energy Relations of Dynamically Loaded Clay S o i l . Trans. Amer. Soc. A g r i c . Eng., V o l . 4, No. 1, pp. 31, 32, 36.  56. 12.  Kaufman, L.C. and D.S. T o t t e n , 1970. Development o f an I n v e r t i n g Mouldboard Plow. Annual Meeting, Amer. Soc. A g r i c . Eng., Paper No. 70-128.  13.  Kim, J . I . , 1970. The Deformation and P r o p e r t i e s o f Cohesive S o i l i n R e l a t i o n to S o i l - M a c h i n e Systems. Mechanical E n g i n e e r i n g Dept., U n i v e r s i t y o f B r i t i s h Columbia, Vancouver, B.C., Unpublished Ph.D. T h e s i s .  14.  K i t a n i , 0. and S.P.E. Persson, 1967. S t r e s s - S t r a i n R e l a t i o n s h i p s f o r S o i l With V a r i a b l e L a t e r a l S t r a i n . Trans. Amer. Soc. A g r i c . Eng., V o l . 10, No. 6, pp. 738-741, 745.  15.  Lambe, T.W., 1967. S o i l T e s t i n g f o r E n g i n e e r s . Wiley and Sons, I n c . , New York.  16.  Murphy, G., 1950. S i m i l i t u d e i n E n g i n e e r i n g . Press Co., New York.  17.  N i c h o l s , M.L., 1931. The Dynamic P r o p e r t i e s o f S o i l . Series of s i x a r t i c l e s . Amer. Soc. A g r i c . Eng. Journal.  18.  N i c h o l s , M.L., I.F. Reed and C.A. Reaves, 1958. S o i l Reaction t o Plow Share Design. Amer. Soc. A g r i c , Eng. J o u r n a l 1, V o l . 39, No. 6, pp. 336-339.  19.  Panwar, J.S. and J.C. Siemens, 1970. S o i l Shear Strength and Energy f o r F a i l u r e R e l a t e d t o Density and Moisture. Annual Meeting, Amer. Soc. A g r i c . Eng., Paper No. 70 - 146.  20.  Reaves, C.A. 1966. A r t i f i c i a l S o i l s Simulate N a t u r a l S o i l s i n T i l l a g e Studies. Trans, Amer. Soc. A g r i c . Eng. V o l . 9, No. 2, pp. 147-150.  21.  Reaves, C.A., A.W. Cooper and F.A. Kummer, 1968. S i m i l i t u d e i n Performance S t u d i e s o f S o i l - C h i s e l Systems. T r a n s . Amer. Soc. A g r i c . Eng., V o l . 11, No. 5, pp. 658-661.  22.  Ross, I . J . and G.W. I s a a c s , 1961. Forces A c t i n g i n Stacks of Granular Materials. Trans. Amer. Soc. A g r i c . Eng. V o l . 4, No. 1, pp. 92-96.  23.  S c h a f e r , R.L., C.W. Bockhop and W.G. L o v e l y , 1968. ModelPrototype S t u d i e s o f T i l l a g e Implements. Trans. Amer. Soc. A g r i c . Eng., V o l . 11, No. 5, pp. 661-665.  24.  Soehne, W.H., 1966. C h a r a c t e r i z a t i o n o f T i l l a g e G r u n d f o r b a t t r i n g 19, pp. 31-48.  John  The Ronald  Tools.  57. Timbers, G.E., L.M. Staley and E.L. Watson, 1965. Determining Modulus of E l a s t i c i t y i n A g r i c u l t u r a l Products by Loaded Plungers. Amer. Soc. A g r i c . Eng. J o u r n a l , V o l . 46, No. 5, pp. 274-275. Vanden Berg, G.E., 1961. Requirements f o r a S o i l Mechanics. Trans. Amer. Soc. A g r i c . Eng., V o l . 4, • No. 2, pp. 234-238. Vanden Berg, G.E. and C.A. Reaves, 1966. C h a r a c t e r i z a t i o n of S o i l Properties f o r T i l l a g e Tool Performance. National T i l l a g e Machinery Laboratory, Auburn, Alabama, U.S.A. Vomocil, J.A. and W.J. Chancellor, 1967. Compressive and T e n s i l e Strengths of Three A g r i c u l t u r a l S o i l s . Trans. Amer. Soc. A g r i c . Eng., V o l . 10, No. 6, pp. 771-775. Wang, J . , K. Lo and T. Liang, 1970. P r e d i c i t i n g T i l l a g e Tool Draft Using Four S o i l Parameters. Annual Meeting, Amer. Soc. A g r i c . Eng., Paper No. 70-129. Wismer, R.D. and H.J. Luth, 19 70. Performance of Plane S o i l C u t t i n g Blades i n Clay. Annual Meeting, Amer. Soc. A g r i c . Eng., Paper No. 70-120. Young, D.F., 1968. S i m i l i t u d e of Soil-Machine Systems. Trans. Amer. Soc. A g r i c . Eng., V o l . 11, No. 5, p p . 6 5 3-658.  58.  APPENDIX  A  60.  FIGURE A 2 .  WHEATSTONE BRIDGE CONFIGURATIONS FOR FORCES AND MOMENTS TO BE MEASURED.  61.  A P P E N D I X  B  62.  FIGURE B l . SCHEMATIC DIAGRAM OF STRAIN GAUGE AMPLIFIERS  63.  PARTS LIST FOR STRAIN GAUGE AMPLIFIERS  Rl  =  1 K ohms  R2  =  switch allows choice o f IK, 1.5K, 2.2K, >4.7K, 10K, 22K, "47K, 100K, 2200K, 4700K, 10 ,000K ohms.  R3  =  I K ohms  R4  =  10K ohms  R5  =  10K ohms  R6  =  1 K ohms  R8  -  10K ohms, 10 t u r n  R9  =  500 ohms e l e c t r i c a l r e s i s t a n c e s t r a i n gauges  CI  =  2200 pF  C2  =  0.1  uF  C3  =  800  yF  T.  -  NPN T r a n s i s t o r )  =  PNP T r a n s i s t o r  1  T  2  )  )  potentiometer  2N4920 2N492 3  NOTES: 1.  Amplification  = R2/R^  2.  A l l grounds t o be c a r r i e d s e p a r a t e l y ground.  3.  C2 c a p a c i t o r s are used t o e l i m i n a t e c r o s s t a l k as 6 s t r a i n gauge b r i d g e s and 6 a m p l i f i e r s were connected i n p a r a l l e l from the same power source.  •4.  Switch f o r R2 must be o f make b e f o r e break type.  t o a common  64.  A P P E N D I X  C  65.  TABLE CI CORRELATION  MATRIX FOR DIRECT SHEAR TESTS FOR OTTAWA SAND. .  w  2  w  E  E  2  Normal Steady Peak  Peak  0.062  0. 061  -0.517  -0.527  0.964  0.970  Steady  0. 080  0. 062  -0.417  -0.423  0.982  1.000  Normal  0. 000  0. 000  -0.405  -0.40 8  1.000  E  0.133  0. 250  0.997  0.128  0. 245  1. 000  0.960  1. 000  E  2  W w  2  1. 000  1.000  1.000  -  TABLE C2 CORRELATION  MATRIX FOR DIRECT SHEAR TESTS FOR HANEY CLAY  W  2  W  E  2  E  Normal Steady Peak  Peak  -0.2714 -0. 160  -0.124  -0.115  0. 767  0.994  Steady  -0 .218 -0. 102  -0.122  -0.118  0. 769  1.000  0. 000  -0.259  -0.2 60  1.000  -0.369 -0. 305  .0.994  1.000  -0.326 -0. 249  1.000  Normal E E  2  W w  0.000  0.963 2  1.000  1. 000 •  1.000  66.  A P P E N D I X  D  67.  TABLE DI  -  CORRELATION MATRIX FOR SOIL-METAL FRICTION TESTS FOR OTTAWA SAND.  T  2  T  W  Water  Normal  Kinetic  2  Static  -0. 396  -0. 426  0. 069  0. 065  0. 978  0. 985  Kinetic  -0. 370  -0. 393  0. 114  0. 112  0. 982  1. 000  Normal  -0. 339  -0. 360  0. 033  0. 015  1. 000  Water  -0. 108  -0. 086  0. 962  1. 000  w  -0. 128  -0 . 105  1. 000  0. 988  1. 000  2  T T  2  Static"  1.000  TABLE D2 CORRELATION MATRIX FOR SOIL-METAL FRICTION TESTS FOR HANEY CLAY  T  2  T  W  Water  Normal  Kinetic  2  Static  -0. 352  -0. 378  0. 380  0. 332  0. 838  0. 936  Kinetic  -0. 358  -0. 385  0. 216  0. 187  0. 890  1. 000  Normal  -0. 375  -0. 396  0. 000  0. 000  1. 000  Water  0. 000  0. 000  0. 952  1. 000  w  0. 000  0. 000  1. 000  T  0. 990  1. 000  T  1.000  2  Static  68.  A P P E N D I X  E  69. TABLE E l CORRELATION MATRIX FOR TILLAGE TESTS FOR OTTAWA SAND  B  2  B  w  2  W  V  T  -0.082  0.656  0.012  0.708  -0.165  -0.160  0.495  0.588  -0.141  -0.136  0.473  0. 555  R  -0.151  -0.146  0.483  0.570  -0.023  0.695  T  0.029  0. 028  0.000  0.000  -0.002  1.000  V  0. 016  0.013 -•0.010 •- 0 . O i l  1.000  F X  F z  W  w  2  B  -0.573  -0.569  0.961  -0.486  -0.484  1.000  0. 999  B  2  1.000  1.000  1.000  R  0.996  F  0.969  0.988  F  F  R  1.000  1.000  1.000 F X  z X  z  TABLE E2 CORRELATION MATRIX FOR TILLAGE TESTS FOR HANEY CLAY B  2  B  w  2  W  V  T  0. 648  0. 644 -0. 281 -0.308  0.178  0. 504  0.591  0.584 -0.219 -0.252  0.188  0 . 541 '  R  0. 613  0.607 -0.241 -0.272  0.187  0. 532  T  ,0.000  0.000  0.000 -0.000  0.003  1.000  "V  0. 004  0.004 -0.010 -0.009  1.000  W  0. 805  F X  F z  w  2  B B  2  -0.800  0. 964  -0.803  -0. 802  1.000  0.999  1.000  1.000  1.000 1.000  R  1.000  0.997  F  1. 000  0. 971  0.986  F  F  F  R  x  z  z X  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0101931/manifest

Comment

Related Items