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N A T I O N A L RESEARCH C O U N C I L O F CANADA
A S S O C I A T E C O h N I T T E E ON S O I L AND SNOV? MECHANICS
PROCEEDINGS O F THIF:
F I F T H
MUSKEG
RESEARCH CONFERENCE4
MARCH1959
O t t a w a
FOREWORD
This i s a r e c o r d of t h e F i f t h Annual Musken Research Conference which was h e l d i n t h e ~ g r i c u l t u r a l B u i l d i n of t h e U n i v e r s i t y of Manitoba i n Winnipeg on
&
Maroh1959.
The Conferenoe was sponsored by the Assoc i a t e Committee on S o i l and Snow Meohanics of t h e National Research Council. Topios c o n s i d e r e d inolude road a o n s t r u c t i o n over organic t e r r a i n , dsterminat
i o n of e n g i n e e r i n g p r o p e r t i e s of t h e organia m a t e r i a l , v e h i c l e s and t r a f f i o a b i l i t y , and drainage. A l i s t of those i n attendance i aincluded aa Appendix A of t h e s e proceedings* I n
the
morning session, under t h e chairmanship of D r . New. Radforth, f i v e papers were p r e s e n t e d and two s h o r t f i l m s were shown. 'Chairman of t h e a f t e r n o o n s e s s i o n was W.C. Harrison; two papers were presented, followed by a g e n e r a l d i s c u s s i o n period d i r e c t e d by Dr. NOW. Radforth.(
ti
) TABLE OF CONTENTSMORN
MG SESSION Tntroduotory Remarks...~...~...
1 S e o t i o n 1-
Reports 1. A n o u t l i n e of c u r r e n t muskeg r e s e a r c h...
i n Canada by Jean Eve1 2
S e c t i o n 2
-
Mechanical P r o p e r t i e s ; Road C o n s t r u c t i o n 1. Summary of "The p r i n c i p l e of p r e c o n s o l i d a t i o nin
highway c o n s t r u c t i o n over muskeg"by C e O . Brawner
. ~ . . . ~ ~ ~ . ~ . ~ . . . . ~ ~ . ~ ~ ~ . ~ ~ ~ ~ ~ ~
13
2. R e l a t i n g t h e e n g i n e e r i n g p r o p e r t l e a of muskeg t o some problems of f i l l c o n s t r u c t i o n
by K.O. Anderson and R.A. Hemstock
...
...'..
16
3.
A n e v a l u a t i o n of same r o a d s over muskegi n
n o r t h e r n Ontario by I v a n C
.
MaoFarlane...
26
S e o t l o n3
-
Vehicles and T r a f f i a a b i l i t y1. Vehicle m o b i l i t y performanoe
i n
muskeg:...
A second r e p o r t by J o G a Thmson31
2. I n t r o d u o t o r y remarks t o f i l m-
F i e l d t r i a l s...
o f muskeg t r a n s p o r t v e h i c l e i n Alberta55
AFTERNOON SESSION S e c t i o n4
-
F o r e s t r y Drainage 1. Aspeots of muskeg a s it a f f e c t s t h e f o r e s t r y...
i n d u s t r y by W.S. Carlson58
2. Aspects of d i t c h i n g and drainage teohniques...
i n
muskeg a r e a s byJ.A.
Cuthbertson 62...
.
S e o t i o n
5
General DiscussSon75
Appendix A
-
List of those p r e s e n t a t t h e F i f t h...
MORN I N Q S E S S
ION
INTRODTJC
TORY REMARKSFollowing r e g i s t r a t i o n , D r . N O W . Radf o r t h introduced
Dean
A.E.
Maadonald of the Faculty of Engineering andArohiteature of the University of Manitoba.
Dean
Maadonald b r i e f l y weloomed delegatest o
the Conferenae on behalf of t h e University. He expressed the hope t h a t they would f i n d t h e d e l i b e r a t i o n s t o be h e l p f u l and t h a t they would r e t u r n a t some f u t u r e date. D r . Radforth then explained the sponsorship of the Conferenae, desoribing the h i s t o r y and functions of theAssoaiate Committee on S o i l and Snow Meohanias and of the Muskeg Suboommittee. A telegram from
Mr.
R.F. Legget, Chairman of the Assoaiate Committee was read, i n which he expressed h i s r e g r e t a t not being able to be present. Delegates attending t h eConf'erenoe were i n v i t e d t o atand giving t h e i r name and t h e i r a f f i l i a t i o n . D r . Radf o r t h then introduaed the Searetary of the Muskeg Suboommittee,
Mr.
1.C.
MaaFarlane, who announced t h e lunaheon arrangements and the a v a i l a b i l i t y of muakeg l i t e r a t u r eREPORTS
1. AN OUTLINE OF CURRENT iVmSKEG RESEARCH I N CANADA
-
Jean Eve1
McMaster U n i v e r s i t y INTRODUCTION
Researoh on organio t e r r a i n , begun i n
l9M
and sponsored by t h e National Research Council and t h e Defence Research Board has brought t o l i g h t many problems shared by those involved i n c o n s t r u c t i o n , a c c e s s , e x p l o r a t i o n o r e x p l o i t a t i o ni n
muskeg a r e a s . Many of t h e s e problems would n o t have been solved hadi t
n o t been f o r s h e e r d e t e r m i n a t i o n t o overoome the muskeg f a c t o r .I n
oases where i t h a s n o t been p o s s i b l e t o simply abandon o p e r a t i o n sbecause of a seemingly i n v i n c i b l e b a r r i e r , t h e problem h a s been f a c e d and o f t e n oolved by t h e a p p l i c a t i o n of basio p r i n c i p l e s of s c i e n c e and engineering.
The d e s i g n of t h i s r e p o r t on c u r r e n t muskeg r e s e a r c h i n Canada i s t o r e f l e c t accrued information from r e p r e s e n t a t i v e s of o r g a n i z a t i o n s known t o have had problems w i t h muskeg i n the p u r s u i t of t h e i r i n t e r e s t s i n i n d u s t r y , t r a n s p o r t a t i o n , c o n s t r u c t ion and a g r i c u l t u r e . It was hoped t h a t information ao obtained might be i n t e g r a t e d i n t o a r e p o r t t h a t could serve a s a souroe of referenoe f o r o t h e r s w i t h s i m i l a r problems i n t h e f i e l d and b r i n g t o l i g h t f u r t h e r problems. Also, from t h i s , i t was thought t h a t t r e n d s f o r f u t u r e r e s e a r c h would become more apparent.
EXPLORATION
The petroleum i n d u s t r y makes e x p r e s s i v e use of t h e term " e x p l o r a t i o n n i n i t s survey a c t i v i t i e s preceding t h e e s t a b l i s h m e n t of produoing w e l l s . T h i s same term could w e l l be used t o convey t h e primary approach t o any muskeg s t u d y t h a t involvea major development. Control of c o s t s , b e s t design, and optimum opera- t i o n a l requirements can only be met i f they a l l p e r t a i n t o a
complete understanding of the p r e c i s e t e r r a i n i n which t h e develop- ment i s t o proceed. Where t h e r e has been success i n muskeg, a s d e f i n e d by t h e s e terms,
it
would be i n s t r u c t i v e t o examine whether t h i s fundamental e x p l o r a t i o n has been adequately c a r r i e d out.
I n g a t h e r i n g information f o r t h i s r e p o r t i t has been encouraging t o f i n d t h a t some use i s being made of what h a s become knovm a s t h e Radforth C l a s s i f i c a t i o n System i n d e a l i n g w i t h muskeg. While i n some i n s t a n c e s i t may not be a p p l i e d w i t h a l l the e x a c t n e s s it i n t e n d s , the p r i n c i p l e s of ooverage recog- n i t i o n and i n t e r p r e t a t i o n a r e being a p p l i e d w i t h success. I n
o t h e r words, i t h a s been found t h a t t h i s system can be u t i l i z e d t o good advantage i n f i e l d o r a e r i a l i n t e r p r e t a t i o n and when used, t h e r e s u l t s have been dependable and f a c i l i t a t e o p e r a t i o n s econo- mically.
The petroleum i n d u s t r y has found i n i t s e x p l o r a t i o n programs t h a t much information b a s i c t o the establishment of w e l l s i t e s can be obtained from a e r i a l photographs. I n b e i q a b l e t o i n t e r p r e t ground c o n d i t i o n s even g e n e r a l l y from a e r i a l photographs, much
time and expense can be e l i m i n a t e d by choosing the s h o r t e s t p o s s i b l e r o u t e t h a t , a t t h e same time, w i l l a v o i d problems i n muskeg a r e a s . If muskeg a r e a s cannot be avoided, the b e s t r o u t e s can be chosen a c r o s s the muskeg by t h e use of the c l a s s i f i c a t i o n system.
Organizations such a s S p a r t a n A i r S e r v i c e s Limited do t h e i r e x p l o r a t i o n work with the a p p l i o a t i o n of the p r i n o i p l e s of the
c l a s s i f i c a t i o n system f o r i n t e r p r e t a t i o n of muskeg areaa. I n t e r - p r e t a t i o n i s done with t h e a i d of a e r i a l photographs, u s u a l l y t a k e n
on s c a l e s between 1,000 and 3,000 f e e t t o 1 inah. Muskegs and a r e a s of u n d e s i r a b l e topography a r e by-passed i n t h e s e l e c t i o n of t h e main r o u t e and a l t e r n a t e r o u t e s a l s o a r e chosen, F i e l d
i n v e s t i g a t i o n s of s e l e a t e d l o o a t i o n s a r e then made f o r t h e i d e n t i f i - c a t i o n of s e a s o n a l drainage o r water t a b l e l e v e l s , depth and n a t u r e of organic m a t e r i a l t o m i n e r a l s o i l type and the c l a s s i f i o a t i o n of muskeg. Additional i n t e r p r e t i v e information d e r i v e d through a
k n m l e d g e of cover and topography can be s u p p l i e d about t r a f f i c a b i l i t y , b e a r i n g s t r e n g t h , r o u t e d e v i a t i o n and Improvement requirements.
CONSTRUCTION
Development i n o r on muskeg a l r e a d y i n v o l v e s many k i n d s of c o n s t r u c t ion, among t h e s e b e i n g e s t a b l i s h m e n t of tank farms, railways, hydro pylons, roads and f o u n d a t i o n s f o r a g r i c u l t u r a l development, e t a .
A t t h i s s t a g e i n our development, t h e most p r e s s i n g needs a r e a s s o c i a t e d w i t h a c c e s s , and c h i e f l y , here, i n t h e c o n s t r u c t i o n of highways.
Second t o a c c e s s , c o n s t r u c t i o n measures such a s housing f o r men and s u p p l i e s a s might be done by t h e A i r Force and o t h e r s e r v i c e s , must be mentioned. That aomtnunities a r e u s u a l l y e s t a b l i s h e d on
mineral s o i l s o r rock foundation does n o t suggest escape from
d i f f i c u l t y , f o r it i s o f t e n t h e a a s e i n t h e n o r t h t h a t muskeg i n t e r - f e r e s i n t h e communications problem.
Where highways a r e concerned, two g e n a r a l f i e l d s of i n - t e r e s t were d e f i n e d i n t h e i n q u i r i e s made f o r t h i s r e p o r t . One i s t h e c o n s t r u c t i o n of highways, frequently p r o v i n c i a l under-
t a k i n g s , t h e o t h e r i s t h e developl~lont of a c c e s s r o a d s f o r p u l p and p a p e r o r petroleum i n d u s t r i e s . One source of i n f o r m a t i o n on high- ways d e a l s w i t h c o n a t r - u c t i o n a s it a p p l i e s i n t h o Yukon* The o t h e r p e r t a i n s t o r o a d b u i l d i n g i n n o r t h e r n O n t a r i o . S o l u t i o n s t o t h e problems i n v o l v e d may w e l l be of v a l u o t o many.
Owing t o t h e g r e a t v a r i a b i l i t y of muskegs i n n o r t h e r n O n t a r i o a n d t o t h e h i g h s t a n d a r d s and economic c o n s i d e r a t i o n s of modern highways, %he O n t a r i o Department of Highways makes u n u s u a l l y
d e t a i l e d s t u d i e s of a r e a s i n o r d e r t o e n s u r e t h e s a t i s f a c t o r y
performance of a r o a d s u r f a c e . Muskeg a r e a s o f t e n cannot be a v o i d e d due t o g e o m e t r i c s t a n d a r d s , and ernbanlments i n t h e s e p l a c e s c a n
r a n g e from
4
t o 40 f e e t .The O n t a r i o Department of Highways r e p o r t s t h a t , " ~ e t ~ i l e d s u r v e y s a r e c a r r i e d o u t on a l l muskega with a p e a t sampler. The
primary purpose of t h i s s u r v e y i s t o determine t h e t y p e and d e p t h of o r g a n i c m a t t e r , the d e p t h of u n d e r l y i n g s o f t m i n e r a l s o i l and t h e t y p e and d e p t h of f i r m bottom. The o r g a n i c m a t t e r i s r o u g h l y c l a s s i f i e d , i,e., w e l l decomposed, p a r t i a l l y decomposed o r f i b r o u s . The s p a u i n g of t h e b o r i n g s i s dependent upon t h e u n i f o r m i t y of t h e m a k e g . However, t h e b o r i n g s do n o t exceed 100 f e e t on c e n t r e l i n e . S i d e b o r i n g s a r e a l s o t a k e n 50 f e e t l e f t and r i g h t of c e n t r e l i n e t o d e t e r m i n e the t r a n s v e r s e p r o f i l e of t h e o r g a n i c m a t t e r and h a r d
bottom. This f a c t o r l a i m p o r t a n t
i n
r o o k and swamp t e r r a i n , where t h e muskeg may have been formed on a s l o p i n g r o o k face.''I n t h e p a s t , t h e O n t a r i o Department of Highways1 p r a c t i c e i n muskeg a r e a s was t o remove a l l t h e o r g a n i c m.atter and t o back-
f i l l w i t h g r a n u l a r m a t e r i a l s . However, t h i s proved t o be econo- m i c a l l y i n i p r a c t i c a l i n many a r e a s where granul-zr m a t e r i a l s were n o t r e a d i l y a v a i l a b l e and l o n g h a u l s of s u i t a b l e m a t e r i a l s were neces-
s a r y . Also, d r a l n a g e i n c l e a r e d a r e a s sometimes proved t o be a problem w i t h some b a c k - f i l l m a t e r i a l s .
I n t h e i r expanding c o n s t r u c t i o n program, p a r t i c u l a r l y
i n
n o r t h e r n O n t a r i o , t h e Department of Highways was f o r c e d t o g i v es e r i o u s c o n s i . d e r a t i o n t o economic problems, e s p e c i a l l y s i n c e granu- l a r m a t e r i a l s a r e o f t e n s c a r c e i n t h e n o r t h . I n a r e a s where mus-
lmgs were r i d d e n i t was d i s c o v e r e d t h a t some o r g a n i c t e r r a i n had b e t t e r b e a r i n g p o t e n t i a l t h a n 0th-ers. These tvro f a c t o r s l e d them
t o a program of muskeg s t u d y , u n d e r t a k e n j o i n t l y w i t h the N a t i o n a l Research Council. T h i s program, begun i n 1958, i s e x p e c t e d t o produce some i n s t r u c t i v e r e s u l t s .
The Department of Highways of B r i t i s h Columbia, a t p r e s e n t t h e major agency concerned w i t h muskeg s t u d i e s i n t h a t provinoe, h a s , i n g e n e r a l , d e a l t w i t h t h e i r muskeg problems by removing a l l
muskeg i n highway c o n s t r u c t i o n where the d e p t h i s l e s s t h a n 1 0 t o 12 f e e t . However, muskegs of g r e a t e r d e p t h a r e o f t e n b u i l t on.
This Department emphasizes problems of s h e a r s t r e n g t h
and s e t t l e m e n t i n i t s c o n t r i b u t i o n t o t h i s r e p o r t . Shear s t r e n g t h i s i n v e s t i g a t e d by vane s h e a r a p p a r a t u s and s e t t l e m e n t c h a r a c t e r i s- t i c 8 of t h e o r g a n i c t e r r a i n a r e i n v e s t i g a t e d w i t h l a b o r a t o r y
c o n s o l i d a t i o n t e s t s f o l l o w e d by f i e l d o b s e r v a t i o n s . I n some i n s t a n c e s i t h a s been n e c e s s a r y t o adopt t h e method of s t a g e c o n s t r u c t i o n of embankments i n order t o l e t t h e muskeg s t r e n g t h b u i l d up a s t h e l o a d i s a p p l i e d , C o r r e l a t i o n d a t a of f i e l d s e t t l e - ment o b s e r v a t i o n s w i t h t h e p h y s i c a l c h a r a c t e r i s t i c s of muskegs a r e b e i n g accumulated.
Muskeg problems on t h e Alaska Highway a r e somewhat d i f f e r e n t because t h . i s was i n i t i a l l y planned a s a g r a v e l road. Considerable
s e t t l e m e n t can be t o l e r a t e d on t h i s highway a s l o n g a s
i t
remains completely p a s s a b l e . Also, heavy maintenance c a n be planned fm
t o r e g r a d e p o r t i o n s of t h e r o a d u n t i l s e t t l e m e n t c e a s e s .
When c o n s t r u c t i o n on a s e c t i o n of t h e Alaska Highway was about t o begin, C a p t a i n Thomson of t h e Northwest Highway Maintenance E s t a b l i s h m e n t i n d i c a t e s t h a t , "a map and a i r p h o t o s t u d y i s made of
t h e a r e a t o e s t a b l i s h t e n t a t i v e c e n t r e l i n e s . T h i s i s f o l l o w e d by f i e l d e x p l o r a t i o n u s u a l l y i n t h e f o r m of probing. Data i s t h e n p l o t t e d and d e c i s i o n s t a k e n concerning p r o c e d u r e s t o be adopted. S l i g h t f i e l d a d j u s t m e n t s may be made a s a o n s t r u a t i o n proceeds."
I n t h e Yukon work, many f a c t o r s such a s d e p t h o f muskeg, l e n g t h t o be t r a v e r s e d , c o n s t r u c t i o n time a v a i l a b l e , a v a i l a b i l i t y of g r a v e l , e a s e of d i s p o s a l o f excavated muskeg, d r a i n a g e and subsequent d i t o h maintenanoe w i l l i n f l u e n c e c o n s t r u a t i o n over muskegs.
The Northwest Highway Maintenance Establishment a l s o f a c e s t h e problem of p e r m a f r o s t , mentioned o n l y b r i e f l y here. It
i s
very d i f f i o u l t t o e x p l o r e o r e x c a v a t e
i n
permanently f r o z e n muskeg, y e t a a l i g h t d i s t u r b a n c e of t h e s u r f a c e can r e s u l t i n l a r g e a r e a sof thawing and i n t u r n , s e t t l e m e n t . Water i n v a r i a b l y f i l l s t h e s e d e p r e s s i o n s and i f t h e s e a r e a s a r e a d j a c e n t t o o r under a road, t h e s t r u c t u r e can be s e r i o u s l y a f f e o t e d .
I n a s p e c i f i o c a s e of c o n s t r u c t i o n on a s e c t i o n of t h e
Alaska Highway which c r o s s e d t h r e e f i n g e r s of muskeg, t h e f o l l o w i n g procedure was taken, a f t e r t h e c e n t r e l i n e had been chosen by a i r - photo s t u d y and ground reconnaiasanoe. It was d e c i d e d t o e x c a v a t e p o r t i o n s of the muskeg t h a t d i d n o t exceed
4
f e e t and t o f i l l over t h e remainder u s i n g c l e a n g r a v e l i n a mat6
f e e t t h i c k . Road grade was a d j u s t e d a c c o r d i n g l y .C o n s t r u c t i o n vras begun i n l a t e A p r i l w i t h b u l l d o z e r s s c r a p i n g o f f l a y e r s of muskeg a few i n c h e s i n t h i c k n e s s a s
i t
thawed. It took two months t o remove a l l the muskeg from t h e p o r t l o n s t h a t were
4
f e e t t h i c k and a t the same time 2 t o3
f e e t of the muskeg over4
f e e t t h i c k were excavated, r e n d e r i n g them less; deep.I n t h e e a r l y f a l l t h e g r a v e l h a u l f o r t h e basecourse began. When muskeg p o r t i o n s were encountered t h e g r a v e l was p l a c e d 2 f e e t thialc by end dumpln over t h e e n t i r e l e n g t h and t h e remainin8
4
f e e t was placed i ng
-
t o 8-inch l i f t s . No d i f f i c u l t i e s were ex- p e r i e n c e d d u r i n g t h e p l a c i n g of the g r a v e l e i t h e r by v e h i c l e s o r byl o s s of m a t e r i a l s i n t o the muskeg.
It may be w e l l t o mention h e r e t h a t t h i s p a r t i c u l a r s e c t i o n of r o a d r e q u i r e d d r a i n a g e , b u t f o r t u n a t e l y t h i s was f a c i l i t a t e d by t h e presence of a r i v e r v a l l e y t o one s i d e of the proposed road. Drainage d i t a h e s were dug down t o m i n e r a l s o i l by means of a clam s h e l l attachment a f t e r t h e f r o z e n l a y e r had been broken by explo- s i v e s . The d i t c h e s , while long, worked w e l l due t o t h e l o c a l topo- gra PRY
I n two s e c t i o n s b o t h p a r a l l e l d i t c h e s had t o be d r a i n e d i n t h e same d i r e c t i o n , n e c e s s i t a t i n g t h e b u i l d i n g of a c u l v e r t beneath t h e road. Drainage on t h e s e s e c t i o n s h a s proved t o be q u i t e s a t i s - f a c t o r y and t h e muskeg became s t a b l e t o t h e p o i n t where
i t
would s u s t a i n l i m i t e d wheeled t r a f f i c and t r a c k e d equipment p r i o rt o
a p p l y i n g t h e g r a v e l f i l l .
On s e c t i o n s of the Alaska Highway where t h e muskeg has n o t been oompletely removed but h a s been r i d d e n , i t i s f i g u r e d t h a t
it
w i l l take
3
t o5
y e a r s of o o n s t a n t maintenanoe b e f o r e the road w i l l become c o n s o l i d a t e d enough t o a p p l y a permanent s u r f a c e , even of g r a v e l .ACCESS ROADS
On t h e s u b j e c t of a c c e s s r o a d s we have 'been f o r t u n a t e i n o b t a i n i n g i n f o r m a t i o n from M r . J. Boulaia, a Road Design Engineer w i t h t h e Royal Canadian A i r Force, H e r e p o r t s t h a t most A i r Force
s t a t i o n s a r e l o c a t e d s o a s t o a v o i d muskegs b u t o f t e n a c c e s s r o a d s t o t h e s e s t a t i o n s a r e n e c e s s a r y . Theso, however, a r e u s u a l l y b u i l t t o p r o v i n c i a l s t a n d a r d s and w i t h t h e co-operation of t h e province, b u t t h e y r e q u i r e s t a n d a r d s of d e s i g n t h a t a r e lower t h a n t h o s e of highways and c i t y s t r e e t s where t r a f f i c d e n s i t i e s a r e h i g h e r .
Rock f i l l s over s o f t f o u n d a t i o n s of 30 f e e t o r more have been found u n s a t i s f a c t o r y because t h e rook c o n t i n u e s t o s e t t l e u n t i l a f i r m f o u n d a t i o n i s reached. Rock may be used i n shallower
muskega where i t i s expected t o r e a c h a f i r n : f o u n d a t i o n d u r i n g c o n s t r u c t i o n o r i n a r e a s o n a b l e p e r i o d of time. Clay i s o f t e n used a s f i l l m a t e r i a l but u s u a l l y betweon l a y e r s of sand o r g r a v e l .
It i s thought t h a t d r a i n a g e a l o n g a c c e s s r o a d s i n muskeg a r e a s would h e l p c o n s i d e r a b l y b u t t h i s i s o f t e n hindered by topo- graphy and i s econoniically i m p r a c t i c a l except f o r t h e more important p r o j e c t s .
When s m a l l b u i l d i n g s a r e r e q u i r e d t o be b u i l t i n permafrost- muskeg a r e a s t h e y a r e b u i l t on 3-to 6-foot g r a n u l a r f i l l s . Larger
b u i l d i n g a a r e b u i l t on p r e c a s t c o n c r e t e p i l e s d r i v e n i n ateam j e t t e d h o l e s . Tho ground f l o o r i s r a i s e d t o provide v e n t i l a t i o n and avoid 1.owering t h e p e r m a f r o s t l e v e l .
I n t h e p u l p and paper i n d u s t r y i n Manitoba, use i s made of muskegsr f o r h a u l i n g d u r i n g t h e w i n t e r because when f r o z e n t h e y a r e l e v e l . The w r i t e r would l i k e t o obaerve h e r e t h a t t h i s kind of o r g a n i c t e r r a i n does n o t c h a r a c t e r i z e t h a t provided w i t h h e a v i e r cover whioh i n w e s t e r n Canada i s o f t e n on h i l l s i d e s and has i n h e r e n t unevenness a s a topographic c h a r a c t e r . The right-of-way i s c l e a r e d
i n l a t e w i n t e r a y e a r i n advance of t h e planned use. Problems a r e encountered t h e next w i n t e r i n p r e p a r i n g t h e r o a d f o r use b e m u s e it o f t e n happens t h a t i t w i l l snow b e f o r e t h e muskeg i s s u f f i c i e n t l y f r o z e n t o permit t h e passage of t r a c k e d v e h i c l e s . The snow a c t s a s a n i n s u l a t o r p r e v e n t i n g f r o s t from p e n e t r a t i n g t h e muskeg. I n c a s e s such a s t h i s t h e snom i s tamped by a l i g h t v e h i c l e , t o a l l o w t h e f r o a t t o p e n e t r a t e . W i t h some f r o s t i n t h e muskeg a h e a v i e r u n i t can t r a v e l u n t i l f i n a l l y a b u l l d o z e r i s used t o push o f f a l l t h e snow t o t h e d e s i r e d r o a d width. The r o a d i s t h e n l e v e l l e d w i t h a heavy d r a g and oan be maintained i n f u t u r e by a motor grader.
When i t i s n e c e s s a r y t o work i n muskeg i n summer, c a r e must be t a k e n n o t t o d i s t u r b t h e r o o t mat. I n f o r m a t i o n provided f o r the section of Manitoba ea st of t h e Winnipeg R i v e r from Lao du Bonnet on t h e s o u t h t o t h e Berens River on t h e n o r t h r e v e a l s t h a t muskegs i n t h i s a r e a a r e extremely wet. T h i s p r e c l u d e s t h e u s e
of t r a c t o r s and h o r s e s . However, p r o v i n c i a l l e g i s l a t i o n p r o h i b i t s t h e c u t t i n g of c o n i f e r o u s s p e c i e s from A p r i l
15
t o October15,
s o many problems a r e avofded.When i t i s n e c e s s a r y t o b u i l d graded r o a d s a c r o s s muskegs i n t h e open season, t h e t r e e s a r e removed fro:a t h e right-of-way t h e p r e v i o u s w i n t e r and t h e grade i s b u i l t up d u r i n g t h e surmner w i t h a d r a g - l i n e o p e r a t i n g on pado.
Advice from t h e E n g i n o w i n g s t a f f of I m p e r i a l O i l Limited i n d i c a t e s t h a t t h e y u s e t h e Radf'orth c l n s s i f i c a t f o n system i n making a c c e s s r o a d s u r v e y s and i n p r e d l c t i n g u l t i m a t e c o s t a and
perfornlance of t h e s e roads. I n a d d i t i o n , a snapping method r e - p o r t e d on a t l a s t y e a r t s t e c h n i c a l s e s s i o n i s now a n a c c e p t e d p a r t of r o u t i n e work a t I m p e r i a l O i l and i s proving s u c c e s s f u l .
The Hydro-Electric Power Commission of O n t a r i o o f t e n
e n c o u n t e r s muskeg i n m a i n t . s i n l n g t h e i r right-of-ways i n a l l p a r t s of O n t a r i o where C o m i s s i o n l i n o s a r e found, T h i s maintenance t a k e s t h e form of mechanical c u t t i n g o r c h o m i c ~ l s p r a y i n g of under- brush. P e r i o d i c p a t r o l s a r e a l s o made of t h e s e r i g h t - o f - m y s t o remove t r e e s t h a t may be dangerous t o t h e powsr l i n o s .
Before t h e advent of chemicsl b r u s h c o n t r o l i n
1949
t h e s e right-of-ways were m a i n t a i n e d by mechanics1 c u t t i n g , t h e men pro- ceeding on f o o t because s u i t a b l e v e h i c l e s were n o t a v a i l a b l e . Around1949,
when chemical b r u s h c o n t r o l came i n t o being t h ea v a i l a b l e v e h i c l e s s t i l l were unable t o n o g o t i a t e muskeg, malring I t n e c e s s a r y t o use l o n g l e n g t h s of hose from v e h i c l e s on h i g h ground a t e i t h e r end of t h e muskeg. Various v e h i c l e s were t r i e d out
i n
an e f f o r t t o f a o i 1 i t a i ; e t h i s o p e r a t i o n and i t was f i n a l l y found t h a t t h e Muskeg T r a c t o r was most s u i t a b l e f o r t h i s purpose i n t r e e d muskeg. The Cammission r e p o r t s g r e a t s a t ; s f a c t i o n w i t h t h e s o v e h i c l e s and r i g h t - o f -ways can now be t r a v e l l e d i n s t r a i g h t l i n e s w i t h a l l equipment and personnel, w i t h s e v e r a l p a s s e s o f t e n b e i n g made over one t r a i l w i t h t h e e x c e p t i o n of some a r e a si n
n o r t h e r n O n t a r i o where i t i s a d v i s a b l e t o use a new t r a i l e a c h time.I n
O n t a r i o , The A b 3 t i b i Power and Paper Company Limited, r e p o r t s problems common t o o p e r a t i o n s i n t h e c l a y b e l t of Ontario. They a r e s e e k i n g s o l u t i o n s t o q u e s t i o n s pertaining t o b e a r i n gs t r e n g t h of muskeg i n b o t h t h e f r o z e n and u n f r o z e n s t a t e s ; methods f o r f l o a t i n g g r a v e l l e d a c c e s s r o a d s t o s u s t a i n heavy l o a d i n g i n t h e open s e a s o n because complete removal of t h e muskeg i s t o o c o s t l y f o r a n a c c e s s road; a t r e a t m e n t f o r s t r a n g t h e n i n g muskeg p r i o r t o p u t t i n g a r o a d subgrade on
it;
methoda of coping w i t h f r o s t damage; d r a inage.
The A b i t i b i Power and Paper Company Limited, have co-
o p e r a t e d w i t h the N a t i o n a l Research Council and MoMaster U n i v e r s i t y t h i s p a s t summer i n t e s t i n g an anchor d e v i c e developed a t NRC.
T h i s anchor, used i n t h e sense t h e word i m p l i e s , h a s proved q u i t e s u c c e s s f u l and i s now s t a n d a r d equipment on t h e y a r d e r s l e d s u s e d i n h a u l i n g l o g s . I t s more fundamental use i n d e m o n s t r a t i n g d i f - f e r e n c e i n l a t s r a l s h e a r value of muskeg mats i s s t i l l under c o n s i d e r a t i o n .
I t i s q u i t e p o s s i b l e t h a t our f u t u r e w i l l see the s p r e a d of a g r i c u l t u r e i n t o t h e vast; a r e a s of n o r t h e r n Canada. Tho problem h e r e w i l l f i r s t be t h a t of d r a i n a g e , whether the l a n d w i l 3 be u s e d f o r c r o p s o r be r e h a b i l i t a t e d f o r o t h e r uses. The b e s t a d v i c e t o g i v e f o r d r a i n a g e i n low a r e a s i s t o use t h e p a t t e r n t h a t conforms t o the l o c a l topography and s t ~ * u c t u r a l d i f f e r e n c e s i n t h e muskeg.
In t h i s c o n n e c t i o n i t can a l r e a d y be o s t a b l i s h o d t h a t ?;:ilea s u r p l u s tvator i s once removed frorn muskeg, t h e p e a t shrinlcs end c o n s o l i d o t u s . To e f f e c t i v e l y remove w a t e r , c o n t o u r d i t c h i n g i s e s s e n t % a l .
VEHICLES
I n any c o n s i d e r a t i o n of a c c e s s
i n
muskeg c o u n t r y t h eq u e s t i o n i n e v i t a b l y a r i s e s a s t o t r a n s p o r t a t i o n of men and s u p p l i e s . P r o g r e s s i s b e i n g mado i n s o l v l n g a c c e s s problems t h r o u g h b e t t e r v e h i c l e design. V e h i c l e s a r e now a v a i l a b l e which t a k e c a r e of most of t h e h a u l i n g problems a r i s i n g i n t h e e x p l o r a t i o n and d r i l l i n g p h a s e s of t h e p e t r o l e u m i n d u s t r y . I m p e r i a l and S h e l l O i l Companies have b o t h shown c o n s i d e r a b l e i n t e r e s t i n t h e Nod\vell v e h i c l e s and have found t h e Scout Car Truck and T r a n s p o r t e r u s e f u l i n h a u l i n g . A g r e a t d e a l of knowledge h a s been o b t a i n e d r e g a r d i n g t h e b a s i o
p r i n c i p l e s of v e h i c l e d e s i g n and of t h e bohaviow and stress c h a r a c - t e r i s t i c s of the muskeg u n d e r v e h i c l e l o a d i n g . By r e d o s i g n i n g and f u r t h e r t e s t i n g
i t
i s hoped t h a t t h e s e v e h i c l e s w i l l be f u r t h e r improved.
The Canadian Army i s f i n d i n g a p p l i c a t i o n i n t h e v e h i c l e
i t
c a l l s t h e
at".
While i t i s c o n s i d e r e d s m a l l by some o r g a n i z a t i o n s , i t s performance may w e l l j u s t i f y t h i s a p p a r e n t l i m i t a t i o n . C o l o n e lR .Lo F r a n k l i n , C h i e f S u p e r i n t e n d e n t of t h e Amy De~relopmont
Es
t a b - l i s h m e n t i n Ottawa r e p o r t s :he
~ r t i c u l a t e d L i g h t Snow T r a c t o r , dubbed t h e "Rat", was developed t o meet a n Army r e q u i r e m e n t f o r a l i g h t prime mover c a p a b l e of c a r r y i n g a l o a d and towing i n f a n t r y s l e d s and toboggans over snow-covered ground. Performance andc a p a b i l i t y was t o be a p p r o x i m a t e l y conzparable t o t h a t of t h e a v e r a g e dog-team, While over-snow o p e r a t i o n via3 t h e primary r e q u i r e m e n t i t was a l s o d e s i r a b l e t h a t t h e v e h i c l e be c a p a b l e of o p e r a t i o n over n o r t h e r n t e r r a i n d u r i n g t h e summer months, i n c l u d i n g muskeg, mud, sand and i n l a n d l a k e s o r r i v e r s . The R a t which i s t h e r e s u l t of a p p r o x i m a t e l y f i v e y e a r s of r e s e a r c h and development f u l f i l s a l l t h e above r e q u i r e m e n t sot'
Tho Rat, c o n s i s t - i n g of t n o u n i t s permanently conneoted by a b a l l j o i n t h a s e x t r e m e l y wide t r a c k s e x t e n d i n g o v e r p r a c t i c a l l y t h e e n t i r e u n d e r c a r r i a g e . The ground p r e s s u r e i s one-half pound p e r s q u a r e i n c h and i n w a t e r i t i s amphibious, b e i n g p r o p e l l e d by t h e t r a c k s and s t e e r e d by a r u d d e r mounted on t h e back of t h e r e a r u n i t . It h a s a speed of 20 m.p.h. on l a n d and
3
k n o t s i n water. The f r o n t u n i t c o n t a i n s t h e engino and t r a n s m i s s i o n ( f o u r f o r w a r d speeds and one r e v e r s e ) , f u e l t a n k s , b a t t e r i e s , t o o l box and d r i v e r . The r e a r u n i t p r o v i d e s 22 s q u a r e f e e t of c a r g o a r e a ,The u n d e r c a r r i a g e of e a c h u n i t c o n s i s t s of a s e t of d u a l d r i v i n g s p r o c k e t s and f o u r f i x o d r u b b e r - t i r e d r o a d whoels f o r each t r a c k , Power i s t r a n s m i t t e d t o t h e d r f v e s p r o c l r e t s of e a c h u n i t ,
t h e t r a c k s being p o s i t i v o l y driven a t t h e same spood, t h e r e being no d i f f o r e n t i a l botweon the t r a c k s , S t o o r i n g i s acco~nplished by a systoin of c a b l e s 015ich pass from t h e l o f t and r i g h t f r o n t
c o r n e r s of tho r o a r u n i t t o a s p i r a l drum nlounted on t h e s t e e r i n g colurnn, When t h e s t e e r i n g v ~ h e e l i s t u r n e d the c a b l e i s taken i n from one s i d e and p a i d o u t t o the o t h e r . This causes t h e r e a r u n i t t o a r t i c u l a t e o r move w i t h r e s p e c t t o the f r o n t u n i t i n t h e h o r i z o n t a l plane and t h e r e f o r e a t u r n of the complete v e h i c l e i s e f f e c t e d .
The Hydro-Electric Povrer Commission of Ontario u s e s Muskeg T r a c t o r s f o r l i n e maintenance and c o n s t r u c t i o n , surveying and f o r g e n e r a l t r a n s p o r t a t i o n of men and m a t e r i a l s . These have been found expensive t o m a i n t a i n but d e s p i t e t h i s , they a r e more economical t h a n any o t h e r v e h i c l e . Any company producing v e h i c l e s of t h i s s o r t must be prepared t o back i t s equipment with good s e r v i c e and r e a d i l y a v a i l a b l e replaoement p a r t s .
So much f o r t r a n s p o r t f o r t r a n s p o r t ' s sake. With even g r e a t e r success here, muskeg can be expected t o have
i t s
v i c t o r i e s both i n the e n g i n e e r i n g and eoonomic realms, f o r adequacy i n t h e m a t t e r of doing a l l o t h e r a s p e c t s of work p e r t i n e n t t o developmenti s but a new-born hope. Here, the Water Buffalo, t h e f i r s t v e h i c l e t o c a r r y heavy tonnage over every kind of muskeg i n Canada, i s
slnowing g r e a t promise. The Water Buffalo can l o a d , excavate, d i t c h and l a y p i p e l i n e , and has been used i n summer t o prepare r o u t e s f o r o t h e r v e h i c l e s .
It remains t o be emphasized t h a t no v e h i c l e w i l l a d e q u a t e l y achieve t h e purpose f o r which
i t
i s intended o r designed, nor w i l l t h e economio environment surrounding off-the-road summer a o c e s s bo s o l i d l y met, u n t i l t h e f i r s t p r i n c i p l e o f the now s t u d y of Terrady- namics i s a p p l i e d-
and t h a t i s t o make i n t e l l i g e n t use of t h e q u a l i t i e s t h e organic t e r r a i n o f f e r s f o r given o p e r a t i o n s . Design f o r o p e r a t i o n must be s u b s i d i z e d by a p p l i c a t i o n of muskeg survey r e s u l t s . Without t h i s , success i s c a s u a l and b i g b u s i n e s s i s n o ti n t e r e s t e d i n t h i s .
DISCUSSION
AND
CONCLUSIONSThis s e c t i o n of the r e p o r t can be b r i e f f o r i n t h e l a t t e r p a r t of t h e f o r e g o i n g s e c t i o n , the key t o success i n muskeg h a s a l r e a d y been i d e n t i f i e d . I n t e n s i v e prelimznary survey, i n c i d e n - ta1l.y t h e cheapest knorvn i n s o i l mechanics, a p p l i e s n o t only f o r s u c c e s s f u l v e h i c l e manoeuvrability and t r a f f i c a b i l i t y , but f o r a l l
The contributions which have o u t l i n e d the g e n e r a l e f f e c t of the impact of muskeg r e s e a r c h have been revealing. Once, a s s c i e n t i s t s and e n g i n e e r s , we dared t o say w e had no problems;
t h e y were mot a s they aroso. But t h i s was a n i l l u s i o n sv~allowed up i n t h e muskeg w i t h a f i n a l i t y more impressive t h a n t h a t p o r t - rayed by a subsiding vehicle w i t h i n a p p r o p r i a t e ground pressure. To r e p l a c e the s p e c t a c l e i s the success s t o r y h e r o i n conveyed. We k n o ~ what t o do about muskeg, evon i f perfectSon i s not y e t achieved.
Also, t h e s e contr:lbutions have given d i r e c t i o n f o r f u t u r e muskeg r e s e a r c h , There a r e s i g n s t h a t fundaniontal r e s e a r c h should t u r n more t o the q u e s t i o n s of how bulk d o n s i t y of muskeg mat oan be determjned, i n t e n s i f T e d o r compensated f o r . I n s i g h t i n t o t h e water r e l a t i o n s of nruskog i n a l l seasons a l s o i d e n t i f l e s new goals.
The foundation, a l r e a d y l a i d , f o r i n t e r p r e t i v e a n a l y s e s of muskeg, i s h a p p i l y conducive t o t h i s
new
program. Indeed, a e r i a l i n t e r - p r e t a t i o n g r e a t l y f a c i l i t a t e s attainment of the n e x t o b j e c t i v e s .The Associate Committee on S o i l and Snow Mechanics, N a t i o n a l Research Council, s i n c e i t s f i r s t i n t e r e s t i n muskeg was shown i n
194-6
through the f o r e s i g h t of M r . R.F. Legget, has sponsored r e s e a r c h i n organic t e r r a i n and h a s supported t h e s e s t u d i e s w i t h i n t e r e s t and f i n a n c i a l assistants. The Defence Research Board, has, a t the same t h e , sponsored and supported t h e a e r f n l i n t e r p r e t a t i o n of organic t e r r a i n . Appreciation f o r continued f i n a n c i a l support f o r muskeg s t u d i e s must, t h e r e f o r e , be f i r s t expressed t o t h e s e twoo r g a n i z a t i o n s o
Acknowledgment must a l s o be given t o t h e r e p r e s e n t a t i v e s of i n d u s t r y , c o n s t r u c t i o n companies and m i l i t a r y e s t a b l i ~ ~ h m e n t s who have been i n t e r e s t e d enough t o provide information f o r t h i s r e p o r t , Without t h e i r encouraging co-operation i t vrould have been most d i f f i c u l t t o b r i n g t h e s e problems, and i n many c a s e s , t h e i r
s o l u t i o n s , t o l i g h t . I n some i n s t a n c e s , it has been necessary t o e d i t c o n t r i b u t i o n s f o r the sake of b r e v i t y
i n
t h . i s r e p o r t , b u t should anyone d e s i r e f u r t h e r information on s p e c i f i c c a s e s , i t can be s u p p l i e d on r e q u e s t . L i s t e d below a r e t h e names of c o n t r i b u t o r s t o t h i s r e p o r t .J.J. Boulais, Road Design Engineer, Department of National Defence, Royal Canadian A i r Force, O t tana, Ontario.
W.G.E. Brovm, Resources Engineering, S p a r t a n A i r S e r v i c e s , Ltd., Ottawa, Ontario.
DOH.
Campbell, Work Equipment Engineer, Hydro E l e c t r i c Power Commfssion of Ontario, Toronto 2, Ontario.Colonel
R.L.
Franlrlin, Chiof Superin.tendont,
A r m y Development Establishment, Department of National. Defonco, ( ~ r m y ) O t tanaW.C. Harrison, Woods Iblanager, Manitoba Paper Co. Ltd,, Pine F a l l s , Manitoba
.
R.A. Hemstock, Iniperfal O i l Limited, Calgary, A l b e r t a ,
H O E o
Hughe a, Union O i l Company of C a l i f o r n i a , Edmonton, A l b e r t a , I .C. MacFarlane, D i v i s i o n of B u i l d i n g Research, Nat i o n a l Research Council, Ottawa,C
.F.
Ripley, Ripley and Associates, Vancouver, B.CA . Rutka, Acting M a t e r i a l s and Research Engineer, Ontario Depart-
n e n t of Highways, Toronto, Ontario.
C .R. S i l v e r a i d e s , Woodlands Development Engineor, A b i t i b i Power and Paper Company, Ltde, Toronto 2, Ontario,
J.F.M. S t u a r t , Area Automotive Superintendent, S h e l l . O i l Company of Canada, Calgary, Alberta.
Captain S, Thomson, Northwest Highway Maintenanoe Establishment, Whitehorse, Yukon T e r r i t o r y .
BIBLIOGRAPHY
Proceedings of t h e Fourth Muskeg Research Conference, Maroh 11,
1958,
NRC, ACSSM Technical Memorandum54,
Ottawa.
Published1958.
Guide t othe
F i e l d D e s c r i p t i o n of Muskeg (based on t h e Radforth C l a s s i f i c a t i o n System). Compiled by I.C. MacFarlane, NRC ACSSMTechnical Memorandum
&
( r e v l s e d e d i t i o n ) , Ottawa, June1958.
A review of the Engineering C h a r a c t e r i s t i c s of Peat, tho J o u r n a l of S o i l Meohanios and Foundation D i v i s i o n of t h e Amerioan S o o i e t y of C i v i l Engineere, Vol.
85,
No. SMI, Feb.1959,
P a r t I, p. 21-35. Muskeg Researoh: A Canadian Approach, by I ,C. MacFarlane,p r e s e n t e d a t the Highway Research Board Annual Meeting
i n
Washington, D.C., January1959.
E v a l u a t i o n of Road Performance over Muskeg i n Ontario, by A. Rutka and I . C , MacFarlane ( i n p r e p a r a t i o n , For p r e s e n t a t i o n t o t h e
S e c t i o n 2
-
RECIUNICAL PROPERTIES; ROAD CONSTRUCTION
1. SUMMARY O F "THE PRINCIPLE OF PRF~CONSOLIDATION I N HIGHWAY
c-ON
~ ~ b b c ~ r 6 , ~ - o ~ ~ E ~ ~ s S ~ - ~ ~
C .O
.
Brawner*B r i t i s h Colunibia Departm.ent of Highways
One of t h e many d i f f i c u l t problems t h a t a Highway Engineer may enoounter i s t h e c o n s t r u c t i o n of a highway over muskeg.
Procedures normally recommended f o r t h e c o n s t r u c t i o n of primary highvrays over t h i s t y p e of t e r r a i n a r e o f t e n e x a e s s i v e l y expensive. Sevepal proposed major highways i n B.C. must t r a v e r s e o r g a n i c
d e p o s i t s i n t h e F r a s e r Rivor d e l t a f o r d i s t a n c e s r a n g i n g from 1/2 m i l e t o 2 m i l e s i n l e n g t h , where t h e p e a t v a r i e s from
8
f t t o15
f t i n depth. To p r o v i d e a s a t i s f a c t o r y r i d i n g s u r f a c e f o r60
mph t r a f f i c , t h e normal procedure would be t o r e p l a c e t h e p e a t w i t h a s u i t a b l e g r a n u l a r m a t e r i a l by e x c a v a t i o n and b a c k f i l l o r by some means of displacement-
a procedure which becomes i n c r e a s i n g l y expensive w i t h g r e a t e r d e p t h s of peat. A s t u d y by t h e B.C.Department at' Highways of o t h e r p o s s i b l e c o n s t r u c t i o n methods suggested t h a t p r e c o n s o l i d a t i o n by s u r c h a r g i n g , o f t e n used t o
s t a b i l i z e s o f t m i n e r a l s o i l s , might p r o v i d e a s t a b l e grade w i t h o u t expensive e x c a v a t i o n o r displacement of t h e peat. T h i s s t u d y
showed t h a t t h e major problems of low s h e a r s t r e n g t h , h i g h
d i f f e r e n t i a l s e t t l e m e n t , e x c e s s i v e quasi-def l e c t i o n and poor d r a i n a g e c h a r a c t e r i s t i c s can be overcome by u s i n g t h e p r e c o n s o l i d a t i o n
t e a h n i q u e , provided a few r e a s o n a b l y simple p r o c e d u r e s a r e followed. Low s h e a r s t r e n g t h s can be i n c r e a s e d by a slovr r a t e of f i l l p l a c e - ment and s h o a r f a i l u r e s can be prevented by t h e i n s t a l l a t i o n of f i e l d i n s t r u m e n t a t i o n t h a t w i l l i n d i c a t e impending i n s t a b i l i t y . D i f f e r e n t i a l s e t t l e m e n t can be m a i n t a i n e d w i t h i n t o l e r a b l e limits by o o n s o l i d e t i n g t h e p e a t d u r i n g t h e c o n s t r u c t i o n p e r i o d by a n amount e q u a l t o o r g r e a t e r t h a n t h a t which would occur i n 2 5 y e a r s
i f no suroharge were u t i l i z e d ( F i g , l ) , Q u a s i - d e f l e c t i o n can be c o n t r o l l e d by employing a d e p t h of pavement (where "pavement" r e f e r s t o the combined t h i o k n e s s of a s p h a l t i c c o n c r e t e and base g r a v e l ) n o t l e s s t h a n
3
1/2 f e e t t h i c k on t h e p r e c o n s o l i d a t e d p e a t . The d r a i n a g e problem i s s i m p l i f i e d , s i n c e d r a i n a g e of t h e p e a t i s n o t recommended. Where c r o s s d r a i n a g e i s n e c e s s a r y , temporary c u l v e r t scan be u t i l i z e d u n t i l s e t t l e m e n t i s l a r g e l y complete, whenoe t h e permanent s t r u c t u r e can be i n s t a l l e d .
The a u t h o r p o i n t s o u t t h a t a l t h o u g h t h e p r e c o n s o l i d a t i o n prooedure has d e f i n i t e m e r i t , i t may n o t necessarXly be t h e most economical procedure.
It
i s sug e a t e d t h a t t h e g r e a t e s t a p p l i o a - t i o n would be f o r d e p o s i t s overd
t o 1 0 f t I n d e p t h and where t h e grade i s r e q u i r e d only a few f e e t above t h e muskeg.It a p p e a r s probable t h a t p r e c o n s o l i d a t i o n can be a p p l i e d s u c c e s s f u l l y i n o t h e r a r e a s and o t h e r t y p e s of p e a t . However, s i n c e t h e t e s t i n g o u t l i n e d i n t h i s paper was c o n f i n e d t o t h e f i n e f i b r o u s p e a t of the Lower F r a s e r Valley a r e a , t h e a u t h o r recom- mends t h a t a d e t a i l e d study precede t h e use of p r e c o n s o l i d a t i o n
T I M E [ D A Y S )
---
TIME-SETTLEMENT CURVE FOR 6' FILLI
---
-TIME-SETTLEMENT CURVE FOR 11' FILLTIME-SETTLEMENT CURVE FOR 11' FILL PLACED
I
FIG. I.- T I M E S E T T L E M E N T CURVES ILLUSTRATING PRECONSOLIDATION PRINCIPLE.
2. RELATING THE ENGINEERING PROPERTIES OF MUSKEG TO SOME PROBLEMS OF FILL CONSTRTJCTION
-
K.O. Anderson, U n i v e r s i t y of A l b e r t a , Edmonton, and R.A. Hemstock, I m p e r i a l O i l Limited, Calgary
I t would indeed be unnecessary t o d i s c u s s i n d e t a i l t h e many problems encountered i n d e a l i n g w i t h muskeg which c o v e r s such a v a s t a r e a i n our Western and Northern Canada. I t i s h e a r t e n i n g t o c o n s i d e r t h e r a t h e r good p r o g r e s s t h a t has been made, p a r t i c u - l a r l y i n t h e p a s t t e n y e a r s , t w r d s a b e t t e r understanding of t h e problems of working i n muskeg.
?18
The f o l l o w i n g i s a b r i e f r e p o r t , more i n t h e n a t u r e of a p r o g r e s s r e p o r t , of c u r r e n t r e s e a r c h underway through U n i v e r s i t y of A l b e r t a and I m p e r i a l O i l Researah Department.
Research c a r r i e d o u t a t t h e U n i v e r s i t y of A l b e r t a i n t h e p a s t has been d i r e c t e d towards i n c r e a s i n g t h e knowledge of t h e e n g i n e e r i n g p r o p e r t i e s of muskeg and a s t o whether the b a s i c s o i l mechanics conoepts u s u a l l y a p p l i e d t o i n o r g a n i c s o i l s oould be a p p l i e d t o o r g a n i c t e r r a i n , g e n e r a l l y termed muskeg. A vane s h e a r t e s t a p p a r a t u s u s i n g a t o r q u e wrench h a s been used t o measure t h e in-place s h e a r s t r e n g t h of d i f f e r e n t t y p e s of muskeg. R e s u l t s
i n d i c a t e d t h a t t h e s h e a r i n g s t r e n g t h s i n c r e a s e d d i r e c t l y w i t h depth, a s h c o n t e n t , and n l a r deformation and v a r i e d inversely w i t h
m o i s t u r e oontent. ?2$
One of t h e main o b j e c t i v e s of the r e s e a r c h program con- ducted t h i a past; summer was t o d e t e ~ m i n e whether t h e s h e a r i n g
s t r e n g t h s a s measured by t h e vane s h e a r t e s t a p p a r a t u s could be used t o determine the maximum s a f e h e i g h t of f i l l on any p a r t i - c u l a r muskeg. ,
Problems concerned w i t h two d i f f e r e n t c l a s s e s of f i l l s c o n s t r u c t e d on muskeg were i n v e s t i g a t e d and c o u l d be d e s a r i b e d a s :
1. minimum s t a n d a r d
--
temporary a c c e s s type of road f i l l2. h i g h e r s t a n d a r d
--
h e a v i e r permanent t y p e road f i l l .Ln
t h e f i r s t type of r o a d c o n s t r u c t i o n t h e concern i s mainly t o o b t a i n a roadway capable of c a r r y i n g a l i m i t e d amount of t r a f f i c f o r a r e l a t i v e l y s h o r t p e r i o d of time, u s u a l l y s e v e r a l y e a r s a t t h e most. I f t h e imported f i l l m a t e r i a l could be k e p tfrom t a k i n g on m o i s t u r e from t h e s u p p o r t i n g muskeg a much l i g h t e r
f i l l t h a n normally r e q u i r e d c o u l d be used and would a d d i t i o n a l l y reduce t h e f r o s t breakup problem i n t h e s p r i n g season. E f f o r t s t o do t h i s w i l l be d e s c r i b e d l a t e r i n t h i s r e p o r t .
With t h e h e a v i e r t y p e of f i l l t h e problem of s h e a r i n g f a i l u r e i n t h e s u p p o r t i n g m a t e r i a l i s t h e main concern t o g e t h e r w i t h t h e amount and r a t e of s e t t l e m e n t of t h e f i l l .
A s u i t a b l e t e s t s i t e t o i n v e s t i g a t e t h e s e problems was l o c a t e d i n a n a r e a approximately 70 m i l e s southwest of Edmonton, Alberta. Topographic c o n d i t i o n s d e f i n e d t h e muskeg a r e a a s
a
ulosed pond form c o v e r i n g a n a r e a about one m i l e i n l e n g t h and one-half mile i n w i d t h (Fig. 1). Analyzing t h e cover p r e s e n t
showed t h a t C l a s s e s F and I were most p r e v a l e n t w i t h v a r y i n g amount8 of B, D and
E.
The cover on t h e edges of t h e muskeg a r e a was l a r g e l y . AEI, which changed t o B E I , BDF and F I p r o g r e s s i v e l y towards t h ec e n t r e of t h e a r e a . The c e n t r a l a r e a was predominantly F I w i t h r i d g e s running a t i n t e r v a l s of 50 t o 80 f e e t whiah c o n s i s t e d of BE1
and p a t o h e s of l o c a l i z e d B D I . The d e p t h of muskeg i n t h e t e s t a r e a g e n e r a l l y ranged from 1 0 t o 12 f e e t w i t h the maximum d e p t h b e i n g
14
f e e t . The s u b s u r f a c e u o n s t i t u t i o n could be d e s o r i b e d a s being f i n e f i b r o u s r a n g i n g t o amorphous.A program was l a i d out t o o o n a t r u o t
( a ) s e v e r a l s e c t i o n s of l i g h t fill i n o r d e r t o i n v e s t i g a t e t h e use of v a r i o u s membranes t o reduoe t h e l o s s of s t r e n g t h i n t h e f i l l r e s u l t i n g from a n i n c r e a s e i n m o i s t u r e c o n t e n t , and ( b ) a f i l l t o f a i l u r e i n o r d e r t o compare v a l u e s of s h e a r i n g s t r e n g t h determined by t h e vane t e s t e r w i t h c a l u u l a t e d v a l u e s a t f a i l u r e c o n d i t i o n s . I n i t i a l i n v e s t i g a t i o n c o n s i s t e d of vane s h e a r t e s t a t o g e t h e r w i t h sampling f o r moisture and a s h c o n t e n t s . The vane t e s t e r
c o n s i s t e d of a
4.5
i n . x 10.1 i n , vane w i t h a 0-300 f t - l b . t o r q u e wrenuh. Using a vane of t h e s e dimensions t h e s h e a r s t r e n g t h ( i n pounds p e r square f o o t ) i s e q u a l t o f i v e i e s t h e t o r q u e i fadvanced t o the d e p t h of t h e vane b l a d e s , 1 2 T I n c a s e s where t h e vane c o u l d be advanced without hand a u g e r i n g t h e corresponding
f a c t o r i s 4.7 due t o t h e l a r g e r s h e a r i n g s u r f a c e . Torque was a p p l i e d a t t h e r a t e of 30 d e g r e e s p e r minute
--
a s low a r a t e a s could be s t e a d i l y a p p l i e d .Remoulded s t r e n g t h t e s t s were t a k e n i n a n a t t e m p t t o de terrnine t h e s e n s i t i v i t y ( r a t i o of u n d i s t u r b e d t o remoulded vane s t r e n g t h s ) of t h e muskeg. A f t e r t h e maximum r e a d i n g had been
o b t a i n e d , t h e vane was q u i c k l y r o t a t e d fow? r e v o l u t i o n e .
The
r e - moulded s t r e n g t h d e t e r m i n a t i o n was s t a r t e d one minute a f t e r t h e f o u r t h r e v o l u t i o n . This procedure i s s i m i l a r t o a method of u s i n g a f i e l d vane a p p a r a t s i n a s e n s i t i v e c l a y found i n t h e St.Lawrence lowlands.
(3
P
Measured s h e a r i n g s t r e n g t h of t h e F I muskeg followed t h e p r e v i o u s t r e n d of i n c r e a s i n g w i t h depth; however, the BE1 muskeg showed a l o s s i n s t r e n g t h down t o a depth of
5
t o8
f e e t , t h e n i n c r e a s i n g with g r e a t e r depth. The moisture p r o f i l e s w i t h d e p t h followed a n i n v e r s e r a t i o ; t h a t i s , i n t h e case of t h e F I muskeg t h e moisture c o n t e n t decreased going from t h e 1 f o o t t o3
f o o t depth, i n c r e a s e d t o5
f e e t t h e n decreased t o 11 f e e t . The t r e n d i n t h e BE1 muskeg was t o i n c r e a s e i n moisture c o n t e n t from t h e s u r f a c e down t o t h e5
t o8
f o o t depths, t h e n a d e c r e a s e w i t h g r e a t e r depth.A p l o t of moisture c o n t e n t v e r s u s u n d i s t u r b e d s h e a r i n g s t r e n g t h (Fig.
3 )
showed a d i r e c t v a r i a t i o n from about 250 l b / f t 2 a t 700% moisture c o n t e n t down t o 100 l b / f t 2 a t 1400%. A band of p l u s o r minus 50 l b / f t 2 from a s t r a i g h t l i n e j o i n i n g t h e s e two p o i n t s would encompass n e a r l y9%
of t h e t e s t r e s u l t a .A s i m i l a r p l o t of t h e remoulded s h e a r i n g s t r e n g t h s showed only v e r y s l i g h t v a r i a i o n w i t h m o i s t u r e c o n t e n t w i t h a l l v a l u e s
B
being below 100 l b / f t.
The s e n s i t i v i t y r a t i o ranged from a lowof
1.5
t o a h i g h of 3.7.The a s h c o n t e n t a s determined by t h e weight of r e s i d u e a f t e r d r y i n g a t 300 d e g r e e s C d i v i d e d by t h e d r y weight of sample a f t e r 2 4 h o u r s a t 110 d e g r e e s C, v a r i e d between a r a t h e r narrow range of 10 t o 25%.
It could be n o t e d t h a t t h e BE1 muskeg had c o n s i s t e n t l y h i g h e r s h e a r i n g s t r e n g t h s t h a n t h e FI down t o a d e p t h of about
8
f e e t . A t t h i s d e p t h t h e r e was an i n s i g n i f i c a n t d i f f e r e n c e i n measured shear'ing s t r e n g t h s * It would appear from a review of t h e d a t a t h a t t h i s h i g h e r s t r e n g t h under t h e BE1 i s due t o t h e lower moisture c o n t e n t brought about by t h e t r a n s p i r a t i o n of m o i s t u r e by t h e s u r f a c e growth, r a t h e r t h a n by a r e i n f o r c i n g e f f e c t of any r o o t s t r u c t u r e *C o n s t r u c t i o n of T e s t F i l l s ( a ) F i l l t o F a i l u r e
The f i l l t o f a i l u r e s e c t i o n was b u i l t on an a r e a of F I muskeg which was 12 f e e t i n d e p t h with t h e water l e v e l a t t h e
s u r f a c e . S e t t l e m e n t p l a t f o r m s c o n s i s t i n g of 2 f t x 2 f t p i e c e s of plywood w i t h 1 i n . d i a m e t e r pipe rod, piezometers of t h e porous
t u b e t y p e ( 4 ) , s u r f a o e gu d l i n e s t a k e s , and p l a s t i c s l i d e s u r f a c e
t ' l
d e t e c t o r s were i n s t a l l e d
5
.
The f i l l had a base width of 4 0 f e e t w i t h t h e t o p b e i n g k e p t a t a minimum w i d t h of approxfma t e l y 2 4 f e e t . The h e i g h t reached a maximum of7
f e e t above w a t e r l e v e l b e f o r e a c r a c k a p p e a r e d along t h e c e n t e r l i n e of t h e f i l l . A drop of 0.7 f e e t o c c u r r e d o v e r n i g h t w i t h no f u r t h e r o b s e r v a b l e movement. S e t t l e m e n t of t h e f i l l b e f o r e f a i l u r e was c l o s e t o6.0
f e e t .Maximum e x c e s s h y d r o s t a t i c p r e s s u r e a t t h e 1 0 t o 1 2 f o o t l e v e l was e q u i v a l e n t t o a head of
8
f e e t of water. Maximum l a t o r a l move- ment of t h e g i v e n s t a k e s was approximately 0.5 f e e t . No d e f i n i t e p l a n e of f a i l u r e was d e t e o t e d w i t h t h e p l a s t i c t u b e i n d i c a t o r s .An a d d i t i o n a l l o a d of
3
f e e ti n
d e p t h p l a c e d t h r e e days a f t e r t h e time of f a i l u r e d i d n o t succeed i n oausing a more pro- nounoed f a i l u r e i n o r d e r t o l o c a t e t h e tow of t h e e x p e c t e d f a i l u r es u r f a c e .
( b ) L i g h t F i l l S e o t i o n s
The muskeg over which t h e s e s e o t i o n s were t o be b u i l t ranged from a s h o r t a e o t i o n of AEI, BE1 t o FI. A l l growth l a r g e r t h a n E growth was out o f f a t t h e s u r f a c e , l e a v i n g o n l y l i g h t growth up t o a maximum of 2 f t . It was planned t o have t h r e e 1 2 5 f t long
s e o t i o n s , a c o n t r o l s e c t i o n w i t h two membrane s e o t i o n s . The f i r s t membrane s e a t i o n was a
4
m i l , t h i o k n e s s p o l y e t h y l e n e p l a s t i c whioh was l a i di n
s t r i p si n
a t r a n s v e r s e d i r e c t i o n . The p l a s t i c was welded t o g e t h e r in t h e f i e l di n
1 2 f o o t w i d t h s , and was l a i d d i r e o t l y on t h e muskeg s u r f a o e .The seoond membrane s e c t i o n was r o l l e d f i b r e g l a s s impregnated w i t h a s p h a l t , The f i b r e g l a s s was
36
i n c h e s i n w i d t h and was over-lapped t o form a double t h i c k n e s s a l s o
i n
t h e t r a n s v e r s e d i r e c t i o n . The a s p h a l t used was a140
degree F s o f t e n i n g p o i n t r o o f i n g a s p h a l t and a p p l i e d by hand a t a r a t e of a p p r o x i m a t e l y 0.4 g a l l o n s p e rs q u a r e yard.
Wtth e x p e r i e n c e g a i n e d i n o o n s t r u c t i n g t h e f i r s t two s e c t i o n s , two f u r t h e r s e o t i o n s of f i b r e g l a s s were l a i d . Beoause of t h e tendenoy f o r opening up of t h e j o i n t s , t h e f i b r e g l a s s was overlapped i n b o t h l o n g i t u d i n a l and t r a n a v e r s e d i r e c t i o n s w i t h c a t a l y t i c a l l y blown a s p h a l t b e i n g used. The a p p l i c a t i o n r a t e f o r t h e f i r s t s e c t i o n was 0.58 g a l l o n s p e r square yard, t h e r a t e b e i n g reduoed t o 0.32 g a l l o n s p e r s q u a r e y a r d f o r t h e seoond s e c t i o n which was oovered w i t h 2 m i l . p o l y e t h y l e n e p l a s t i c .
Observations ( a ) S h e a r i n g S t r e n g t h s
The s h e a r i n g s t r e n g t h of t h e FI muskeg from t h e vane s h e a r t e s t b e f o r e c o n s t r u c t i o n a s determined from s e v e r a l t e s t s ranged from 100 pounds p e r square f o o t a t
