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Theory of distribution of stresses in granular soil foundation
95 W h i l s t r o l l of the e r e c t o r end t r a i l e r bodies i s n o t i n c l u d e d as • degree of ireedom0 the changes of v e r t i c a l l o a d i n g of the t y r o s Ln c o r n e r i n g are allowed f o r by approximate c a l c u J . , • i o n . S e n i o e m p i r i c t l e q u a t i o n s evolved by Smiloy and Horn* • r e used to * v a l u a t e the c o r n e r * i n s pertormance of pneumatic t y r s e . Tee e q u a t i o n • of motion f o r the mechanics] model of the t r a c t o r / s e m i - t r a i l e r oomblaatlon, a t • defaced and two b a s i c problem• of h a n d l i n g are t r e a t e d : (L) chat of c o n t r o l l i n g the v e h i c l o to f o l | o w a d e s i r e d c i r c u l a r p a t h , as•steaMed o i t h the s t e e d y o s t a t e s o l u t i o n of the e q u a t i o n • of motion and (2) t h a t of dynamic s t a b i l i t y sgnLnJC •mall e x t e r n a l d i s t u r b a n c e s , e x p r e s s e d by the s o l u t i o n of oh. c h a r a c t e r i s t i c e q u a t i o n of the v e h i c l e . R e s u l t s of • s e r i e s of sample c a l c u l a t i o n s s t . p r e s e n t e d . These show how the s t e e r i n g c h a r a c t e r i o t l c s are a f f e c t e d by v a r i o u s v e h i c l e - d e s i g n p a r a m e t e r s , such as p o s i t i o n of . e n t r e e of g r a v i t y of t r a c t o r sad s e m i - t r a i l e r , d i s t a n c e of k i n g p i n from s e m i - t r a i l e r a x l e , s e m l - t r a L l e r l e n g t h , l o a d i n g c o n d i t i o n , yawing moment o f i n e r t i a , and t y r e c h a r • c t e r i s t l o n . The c a l c u l a t i o n s a l s o •how Chat Ehe r a d i u s of t u r n and v e h i c l e • p . e d have • mcrked e f f e c t oa the d i r e c t i o n a l behavLour of the t r a c t o r / s e m i - t r a i l e r combine•Los. 68. ~ d a u r o v , I . L " Theory o f d i s t r i b u t i o n o£ s t r e s s e s An g r a n u l a r s o i l £onndacion" ~in [~usalan), Oanc~an~ya, Fundaaznty ~ Mekh. Grlmtov, /Vo.~, 1960. The p r o b | e m c o n s i d e r e d i s t h a t of the transmAssLoa of f o r c e s in a g r a n u l a r s e l l foundat i o n . Q u a l i t a t i v e a n a l y s i s of t h e d i s t r i b u t i o n s of f o r c e • in g r a n u l a r media, w i t h o u t and with t h r u s t , l e a d s to • c o n c l u s i o n chat ia both c a s e s , in c o n n e c t i o n wlch c a l c u l a t i o n of v e r t i c a l s t r e s s e s , the p a r t i c l e s have the same }ayour4 Hence the s o l u t i o n f o r the t h r u s t s y s t e m can be o b t a i n e d from t h a t f o r the c h r u s t l o s • one by i n t r o d u c i n g • v a r i a b l e coe f f i c i e n t of i n e q u a l i t y of f o r c e t r a n s m i s s l o n . A c a l c u l a t i o n L• given of f o r c e s with a c e r t a i n p o s t u l a t e d e x p r e s s i o n f o r t h e i r c o e f f i c i e n t of i n e q u a l i t y , when the h o r i • a n t a l , normal, sad t a n g e n t i a l • t r e s s e s were c a l c u l a t e d j u s t as f o r • c o n t i n u o u s medium. Experimenta] dace o b t a i n e d e a r l i e r arm compared with the a u t h o r ' s c a l c u l a t i o n s , and i t i s o b s e r v e d t h a t they agree c l o s e l y . 69. K a r l s s o a , R. " O n C o h e s i v e S o i l s and T h e i r Flow P r o p e r t i e s " , Swecl~sh C,eotcc~icaL I n s t . ,
Stockho la, Rap.No. 5, 1963. F a l l - c o n e and A t t e r b o r g T e s t s yore performed on remolded c l a y samples and the r e s u l t s correlated. ?0. Knizht, S . J . , R u s h , E.S.& S t / n s e a , B.G. " T r a £ f i c a b i l i c y T e s t a w i t h the Marsh Screw Amphibian on C o e r s e - C ~ a i n e d and F i n e - C ~ a i n e d S o i l s " . U.S.Ara7 F.agineer Wa¢crvays ~=p:.Stn.Tech. R e p o t : No. 3-641, J a n . I ~ . The Marsh Screw Amphibian i s of i n t e r e s t in the Army's m o b i l i t y r e s e a r c h program because of i t • unusual concept of locomotion which i s based on the Archimedean •crew. I t move• by means of two c o c n C e r r e t a t i a g r o t o r s which give f o r w a r d and backward t h r u s t to the v e h i c l e . When both r o t o r s • r e made to t u r n i a the some d i r e c t i o n , the v e h i c l e w i l l move l a t e r a l l y ; however, t h e r e i s no p r o v i s i o n f o r s t e e r i n g when the v e h i c l e i s moving l a t e r a l l y . T r e e . f i c a b i ] L t y t e s t s w i t h the Marsh Screw were p e r f o r m e d to d e t e r m i n e i t s performance on t h r e e s o i l t y p e s : sand. c l a y , and J i l t . R e p e t i t i v e - p a s s t e a t s and speed t e a t 8 were conducted on c l a y end sand; towing t e s t a on c l a y . s i l t , and sand; s l o p e - c l i m b i n g t e s t a on •and; and o b s t a c l e t e s t s on s i l t . For comparison, t e s t s w i t h aa M29C veane] were conducted and p e r formanee cmrvea from previous t e s t proj~rut• were u t i l i z e d . ~ppendix A proseat8 • d e t a i l e d d e s c r i p t i o n of the d e t e r m i n a t i o n of m o b i l i t y i n d e x e s and v e h i c l e cone index f o r the Marsh $cre,d. Appendix B d i s c u s s e s the power o r a l s s y s t e m . ?1. ~olb, C.g. & Shambarzer, J.H. " P r o j e c t O t t e r (Overland T r a i n T e r r a i n E v a l u a t i o n R e s e a r c h ) ; P r e - T e s c B e p o r c ' . U.~.Aray F.ng~neer ~ a c e r ~ s ~zp¢.~tn.Tech.R~port No.3-588, D e c . l ~ l . Perfoz~nance in d e s e r t • r e • • of the Overland T r a i n , • l o g i s t i c a l cargo c a r r i e r , i s to be t e s t e d in 1962 s t the Yuma T e s t S t a t i o n by the U.S.A~my T r a n s p o r t a t i o n Research Commend (TP~GOJd). To r e a l i s t i c a l l y evaluate t e s t r e s u l t • , ~ needs to know the r e p r e s e n t a t i v e n t i s of the t e r r a i n over which Ohm Overland T r a i n i s t e s t e d compared r i c h world d e s e r t t e r r a i n c o n d i t i o n s . P r o j e c t s concerned w l t h t e r r a i n a n a l y s i s and e v a l u e t l o n have been conducted a t the Waterways Experiment S t a t i o n (WES) f o r s e v e r a l y e a r s , and • c l a s s / f / c a t i o n system and t e c h n i q u e f o r mapping t e r r a i n f a c t o r • have been developed. Many d e s e r t s , i n c l u d i n g t h a t s t Ynma, hove been napped. From the Yuma c e r t a i n f a c t o r maps, c a s t c o u r s e s for the Overland Train were tentatively selected. A major field investigation was then conducted of t h e s e c o u r s e s . T e r r a i n t y p e s c l a s s i f i e d a c c o r d i n g to the W~ system a l o n g n i n e of the c o u r s e s are t e n t a t i v e l y compared to the t e r r a i n of world d e s e r t s . A d d i t i o n a l r e p o r t s are p l a n n e d a f t e r a c t u a l t e a • l a g i s completed. 72. Kuiperu, U. D r u k v e r d e l i n g o n d e r ]andbouwvoercuige~ [ S t r e s s discribucic8~ u n d e r ~arm v e h i c l e s ] L a n d b - ~ e c h a n t ~ a ¢ i c , J~3. L i t e r a t u r e on the magnitude end d i s t r i b u t i o n o f s t r e s s under t r a c t o r wheels and crooks i s reviewed sad the d i f f e r e n c e f o r hard, normal and s o f t ground d i s c u s s e d . Soil s t r u c t u r e
Stockho la, Rap.No. 5, 1963. F a l l - c o n e and A t t e r b o r g T e s t s yore performed on remolded c l a y samples and the r e s u l t s correlated. ?0. Knizht, S . J . , R u s h , E.S.& S t / n s e a , B.G. " T r a £ f i c a b i l i c y T e s t a w i t h the Marsh Screw Amphibian on C o e r s e - C ~ a i n e d and F i n e - C ~ a i n e d S o i l s " . U.S.Ara7 F.agineer Wa¢crvays ~=p:.Stn.Tech. R e p o t : No. 3-641, J a n . I ~ . The Marsh Screw Amphibian i s of i n t e r e s t in the Army's m o b i l i t y r e s e a r c h program because of i t • unusual concept of locomotion which i s based on the Archimedean •crew. I t move• by means of two c o c n C e r r e t a t i a g r o t o r s which give f o r w a r d and backward t h r u s t to the v e h i c l e . When both r o t o r s • r e made to t u r n i a the some d i r e c t i o n , the v e h i c l e w i l l move l a t e r a l l y ; however, t h e r e i s no p r o v i s i o n f o r s t e e r i n g when the v e h i c l e i s moving l a t e r a l l y . T r e e . f i c a b i ] L t y t e s t s w i t h the Marsh Screw were p e r f o r m e d to d e t e r m i n e i t s performance on t h r e e s o i l t y p e s : sand. c l a y , and J i l t . R e p e t i t i v e - p a s s t e a t s and speed t e a t 8 were conducted on c l a y end sand; towing t e s t a on c l a y . s i l t , and sand; s l o p e - c l i m b i n g t e s t a on •and; and o b s t a c l e t e s t s on s i l t . For comparison, t e s t s w i t h aa M29C veane] were conducted and p e r formanee cmrvea from previous t e s t proj~rut• were u t i l i z e d . ~ppendix A proseat8 • d e t a i l e d d e s c r i p t i o n of the d e t e r m i n a t i o n of m o b i l i t y i n d e x e s and v e h i c l e cone index f o r the Marsh $cre,d. Appendix B d i s c u s s e s the power o r a l s s y s t e m . ?1. ~olb, C.g. & Shambarzer, J.H. " P r o j e c t O t t e r (Overland T r a i n T e r r a i n E v a l u a t i o n R e s e a r c h ) ; P r e - T e s c B e p o r c ' . U.~.Aray F.ng~neer ~ a c e r ~ s ~zp¢.~tn.Tech.R~port No.3-588, D e c . l ~ l . Perfoz~nance in d e s e r t • r e • • of the Overland T r a i n , • l o g i s t i c a l cargo c a r r i e r , i s to be t e s t e d in 1962 s t the Yuma T e s t S t a t i o n by the U.S.A~my T r a n s p o r t a t i o n Research Commend (TP~GOJd). To r e a l i s t i c a l l y evaluate t e s t r e s u l t • , ~ needs to know the r e p r e s e n t a t i v e n t i s of the t e r r a i n over which Ohm Overland T r a i n i s t e s t e d compared r i c h world d e s e r t t e r r a i n c o n d i t i o n s . P r o j e c t s concerned w l t h t e r r a i n a n a l y s i s and e v a l u e t l o n have been conducted a t the Waterways Experiment S t a t i o n (WES) f o r s e v e r a l y e a r s , and • c l a s s / f / c a t i o n system and t e c h n i q u e f o r mapping t e r r a i n f a c t o r • have been developed. Many d e s e r t s , i n c l u d i n g t h a t s t Ynma, hove been napped. From the Yuma c e r t a i n f a c t o r maps, c a s t c o u r s e s for the Overland Train were tentatively selected. A major field investigation was then conducted of t h e s e c o u r s e s . T e r r a i n t y p e s c l a s s i f i e d a c c o r d i n g to the W~ system a l o n g n i n e of the c o u r s e s are t e n t a t i v e l y compared to the t e r r a i n of world d e s e r t s . A d d i t i o n a l r e p o r t s are p l a n n e d a f t e r a c t u a l t e a • l a g i s completed. 72. Kuiperu, U. D r u k v e r d e l i n g o n d e r ]andbouwvoercuige~ [ S t r e s s discribucic8~ u n d e r ~arm v e h i c l e s ] L a n d b - ~ e c h a n t ~ a ¢ i c , J~3. L i t e r a t u r e on the magnitude end d i s t r i b u t i o n o f s t r e s s under t r a c t o r wheels and crooks i s reviewed sad the d i f f e r e n c e f o r hard, normal and s o f t ground d i s c u s s e d . Soil s t r u c t u r e