Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la
première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site
LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
Technical Translation (National Research Council of Canada), 1984
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC : https://nrc-publications.canada.ca/eng/view/object/?id=5d968f36-00af-40c9-8282-1b8ccad45c14 https://publications-cnrc.canada.ca/fra/voir/objet/?id=5d968f36-00af-40c9-8282-1b8ccad45c14
Archives des publications du CNRC
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/20386667
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Permafrost research and engineering in China
ＬｾｊＭｉ
I/tf
'f
1)(., L1(/.;(,
fr
ＭＩｏｾｌ
CANADA INSTITUTE
FOR SCIENTIFIC AND TECHNICAL
INFORMATION
ISSN 0077-5606
INSTITUT CANADIEN
DE L'INFORMATION SCIENTIFIQUE
ET TECHNIQUE
NRC/CNR TT-2082
f
TECHNICAL TRANSLATION TRADUCTION TECHNIQUEPERMAFROST RESEARCH AND ENGINEERING IN CHttNA
A COLLECTION OF PAPERS SELECTED FROM THE 1979 TO
ＱＹＸｾISSUES OF THE CHINESE JOURNAL OF GLACIOLOGY AND CRYOPEDOLOGY
(BINGCHUAN DONGTU)
Prepared for the Division of Building Research and the Permafrost Subcommittee
Associate Committee on Geotechnical Research National Research Council Canada
THIS IS NUMBER 253 IN THE SERIES OF TRANSLATIONS
PREPARED FOR THE DIVISION OF BUILDING RESEARCH
TRADUCTION NUMERO 253 DE LA
ｓｾｒｉｅ ｐｒｾｐａｒｾｅPOUR
,.LA DIVISION DES RECHERCHES EN BATlMENT
OTTAWA
1984
1+
National Research Council Canada Conseil national de recherches CanadaAbout 22 per cent of the People's Republic of China is underlain by
permafrost. Although permafrost is widespread in northeast China, more than 70 per cent of the permafrost region lies in western China where perennially frozen ground is found at high elevation in the mountains and on the Qinghai-Xizang (Tibet) Plateau (generally above 4000 m a.s.l.).
Many permafrost engineering problems have been experienced during the developmen t of resources and transportation facilities (railways and highways) in the mountainous and northern areas of China. Permafrost investigations began in northeast China in the 1950's and in western China in the 1960's. In addition, considerable progress has been made in studies of associated periglacial features. Since 1975, when the first contact was made with Chinese permafrost workers, the Division of Building Research has endeavoured to keep abreast of developments in these fields by maintaining these contacts and through reports in the literature.
The Journal of Glaciology and ｃｲｹｯｰ･､ｯｬｯｧｹｾ pUblished by the Lanzhou Research Institute of Glaciology and Cryopedology, Academia Sinica, contains an excellent record of the development and status of permafrost research and engineering in China and, therefore, is of special interest to Canadian permafrost workers. The first issue appeared in 1976, the second in 1979, and since 1980 the Journal has been published as a regular periodical with at least four issues per volume each year. Translations of papers selected from the 1979, 1980 and 1981 issues are contained in this publication.
Sincere appreciation must be expressed to those who translated the papers: Chester C.C. Hsia, Nancy McNamer, Richard RObb, Esther Su, and Edward Suen. The work of Georgette Legault, CISTI/NRC Translations, in organizing all the translations and producing the final typewritten manuscripts is a Lso gratefully acknowledged. Special thanks are due also to the following members of the Permafrost Subcommittee, Associate Committee on Geotechnical Research, NRCC, who edited the translations:
H.M. French (Papers 2, 11, 13, 16 and 19) S.A. Harris (Papers 9 and 20)
D.W. Hayley (Papers 5 and 14)
J.A. Heginbottom (Papers 10 and 18) G.H. Johnston (Papers 4 and 12) D.E. Pufahl (Paper 3)
D.C. Sego (Paper 8)
W.A. Slusarchuk (Papers 1 and 15)
R.O. van Everdingen (Papers 6, 7 and 17)
The general editor for the Collection was G.H. Johnston, Division of Building Research and Research Advisor to the Permafrost Subcommittee.
H.M. French Chairman
Permafrost Subcommittee Associate Committee on
Geotechnical Research
National Research Council Canada
C.B. Crawford Director
Division of Building Research National Research Council Canada
INTRODUCTORY NOTE
Several individuals were involved in translating the papers in this Collection. Systems used for transcribing words from the original Chinese have undergone changes in recent years due to changes in the language and the adoption of new phonetic pronounciation systems. When the papers were edited, an attempt was made to check the spelling of place names in particular, but some differences may exist, especially with regard to less well known places and geographical features or areas.
Several maps have been included to show political divisions (provinces, etc.), locations of major cities and mountain ranges in the permafrost region of China and the distribution of permafrost and seasonally frozen ground in China.
The following publications (in English) will be of interest to those wishing additional information on permafrost in the People's Republic of China.
(l) Permafrost by the Research Institute of Glaciology, Cryopedology and Desert Research, Academia Sinica, Lanzhou, China, 1915. National Research Council Canada, Canada Institute for Scientific and 'Technical Information, Technical Translation No. TT-2006, Ottawa, 1981, 224 p.
(2) The Second National Chinese Confer-ence on Permafrost, Lanzhou, China, October 12-18, 1981 by Jerry Brown and Yin-Chao Yen. U.S. Army, Cold Regions Research and Engineering Laboratory, Special Report 82-3, March, 1982, 62 p,
(3) Bibliography of Literature on China's Glaciers and Permafrost. Part I: 1938-1919. Shen Jian and Zhang Xianggong, Editors. U.S. Army, Cold Regions Research and Engineering Laboratory, Special Report 82-20, September, 1982, 50 p.
(4) Proceedings Fourth International Conference on Permafrost; Held in Fairbanks, Alaska, July, 1983, Published by U.S. National Academy Press, Washington, Vol. 1, 1524 p. (Contains 40 papers from China.)
In addition to the Journal of Glaciology and Cryopedology, which is published regularly in Chinese - with English abstracts, and has at least four
issues per volume each year (Volume 5 appeared in 1983), the following
pUblications (in Chinese) will also be of interest.
(1) Proceedings of a Symposium (First National Conference) on Glaciology and
Cryopedology held in Lanzhou, China, November 27-December 3, 1978.
Edited by the Lanzhou Institute of Glaciology and Cryopedology (1982),
210 p.
(2) Proceedings of Second National Conference on Permafrost held in Lanzhou,
China, October 12-18, 1981. Gansu People's Publishing House (1983), 509
p.
(Collection of) Professional Papers on
QINGHAI-XIZANG (Tibetan) Plateau, Edited
Glaciology and Cryopedology, 1983, 269 p.
Permafrost by Lanzhou Studies Institute of of
The Tables of Contents (in English) of these last three. publications are reproduced in an Appendix to this Collection.
TABLE OF CONTENTS
[NOTE: All papers are from the Chinese Journal of Glaciology and Cryopedology (BINGCHUAN CONCTU).]
PREFACE INTRODUCTORY NOTE MAPS Paper No. 1 5
(l) Thirty Years of Permafrost Research and Engineering in China by
CHEN SHIAOPIO, TUNG PUOLIANG, WING JINKANG and ZHOU CHANGQING. 9 Issue No.2, 1979, pp. 7-12.
(2) Cer:ain Distinctions Between the Permafrost of the Chinese 25
Qinghai-Xizang (Tibetan) Plateau and that of the Canadian North by CHENG GUODONG. Issue No.2, 1979,
PP.
39-42.(3) Problems of Roadbed Stability in the Construction of an Asphalt 35
Surface for the Qinghai-Xizang (Tibetan) Highway in China's Permafrost Region by ZHU XUEWEN and the Scientific Resear-ch Group for the Qinghai-Tibetan Highway, Ministry of Communications. Issue No.2, 1979, pp. 43-51.
(4) A Geotechnical Classification of Permafrost by WU ZIWANG. Issue 59
No.2, 1979, pp. 52-60.
(5) A Review of the Achievements in the Study
or
Bases and Foundations 77on Frozen Ground in China by ZHOU CHANGQING. Vol. 2, No.1, 1980,
pp. 1-5.
(6) Frozen soil and Groundwater by WENG BINGLIN. Vol. 2, No.1, 1980, 91 pp. 21-22.
(7) The Selection and Evaluation of Water-Supply Sources in the Da and 93 Xiao Hinggan Ling Permafrost Areas by LIN FENGDONG. Vol. 2, No.
1, 1980, pp. 32-36.
(8) A Preliminary Experimental Study on the Instantaneous Strength of 105 Frozen Sand by LIAN HUISHENG, ZHAO LIN and WANG JIACHENG. Vol. 2,
No.1, 1980, pp. 37-40, 31.
(9 ) On Geomorphological Indicators of Permafrost and Between Glaciation and Periglaciation by CUI ZHIJIU. 2, 1980, pp. 1-6.
the Relation Vol. 2, No.
Paper No.
(10) The Active Layer at the Southern Foot of Tanggula Shan by TONG 133 BOLIANG, XIE YINQIN, GUO DONGXIN and WANG JIACHENG. Vol. 2, No. 2, 1980, pp. 19-24.
(11) The Characteristics of Ground Ice Along the Qinghai-Tibetan 147 Highway in the Fenghuo-Shan District by LI LIE AND XING ZEMIN. Vol. 2, No.2, 1980, pp. 31-35, 18.
(12) Discussions and Opinions on the Paper "A Geotechnical 163 Classification of Permafrost" (see Paper 4 in this collection)
by ZHANG CHANGQING. Vol. 2, No.2, 1980, pp. 58-60.
(13) Modern Periglacial Processes in the Central Tian Shan by JI 171 ZIXIU. Vol. 2, No.3, 1980, pp. 1-11.
(14) The Effect of Grain Size Distribution on Frost Heave in Fine Sand 205 by WANG ZHENGQIU. Vol. 2, No.3, 1980, pp. 24-28.
(15) Experimental Research on Frost Heave in Various Soils at Different 217 Groundwater Levels by WANG XIYAO. Vol. 2, No.3, 1980, pp. 40-45.
(16) Determination of the Ancient Permafrost Table Based on the 231 Variation in the Content of Clay Minerals by XING ZEMIN, WU XIAOLING and QU RONGKANG. Vol. 2, Special Issue, 1980, pp. 39-44.
(17) Hydrogeological Investigation Methods and Exploration for Water in 241 the Permafrost Region of Qilian Shan by CAO JIYE. Vol. 3, No.1, 1981, pp. 59-64.
(18) Principles for Compiling Permafrost by CHENG GUODONG.
Large Scale Ice Content Maps Vol. 3, No.3, 1981, pp. 53-57.
of 255
(19) Pingos of the Qingshui River Valley on the Qinghai-Tibetan Plateau 265 by WANG SHAOLING and YAO HEQING. Vol. 3, No.3, 1981, pp. 58-62.
(20) Progress in the Study of Periglacial Landforms in China by CUI 275 ZHIJIU. Vol. 3, No.3, 1981, pp. 70-77.
V1 XINJIANG UYGUR ZIZHIOU XIZANG ZIZHIOU
GANSU OlNGHAI
NINGXIA HUIZU ZIZHIOU SICHUAN
YUNNAN
NEI MONGGOl ZIZHIOU SHAANXI
GUIZHOU
GUANGXI ZHUANGZU ZIZHIOU SHANXI HENAN HUBEI HUNAN GUANGDONG HEILONGJIANG JILIN LIAONING HEBEl SHAN DONG ANHUI JIANGSU JIANGXI ZHEJIANG FUJIAN QINGHAI-XIZANG (TIBET) HIGHWAY 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24 . 25. 26.
-50 30 20 JA"AN BR 6493-3 140 ｾｨＮｮｧｨＮｩ 130 110 170 " • Ulan n",", • Irlclthk,
MONr.OU/\ 1I<;<;11 / \-"
....
". . -, 80 , ... J ..-.j,
, .r:_ . _ ..."i INOlA , I , I I ! I I I I I o km 1000PFOPI.U; nFPUBlIC Of CHIN/\
POLITICAL DIVISIONS »: - . - . ,
",
" / " Kh;d'JWY"Iol;
Ｎ｟ＮＭＮＮＮＮＮｾ ｾ - ... " .../ I , i " 11 i i._ ..."'...._0 ... _\ .
. i fhthm._0
\-
-
, \ I " . ' r \ , - . , . - u " 18r("
VliuUv""to,," • ｜Ｂｵｭｾｩ ' .,
. .
" ,- 1'1 I .r'>:I " " 140 \-
,...
---.
,
"',
\. J.... • - • - . " . . .,.;I> , _ " ... ,.- 1;...ｾ .»::1/,,', -""'- .
- !
f \ｾＬ
, r- - )Ｉｾｾ
-" ＮＧｾＬ _ ｾｌ ｾ _ / I ｾ <I" 1 - , I ｾ • r -.., - , ; I 10 11- ｾ , " I '" ( , ' Z _ l I ' J ' . . . . _ r : I? I ｾＬ 1, '. _ . - - - , ; , _ , r... I ｾ ｾ 21 ｾ｜ ｾＱＱ ｾＮＮｊ - ' - - ｾＭ • Golmud , ＮｾＬ \ I-/, 'L ,y:
J.
'-J " _ c, Iｾ
'I;,./' '\.. \ • . ./LHlIhn",...ｾ｟
. ./ ...ｾｾ
..ｾ
I,'V
,
ｾ (J .., \ 'I \ 13 1.J , i ' • 2 \, . - _ ｾ .. \ r ｾ \. ｾ ...I'
2.' ... - . _. -{ \ .J , .... "'" f ... - ... . 22 )... ' _ / \. 8 ｾＧＢ ｾＮＮＺＧ ' f -... ) t h n " d u ' 14 , I ',. \ . r-r .,.." ｾ t ) ｾ " , ' . • Lhl.. I .. Ｍｾ - - ｾ _ - Ｑｾ \'" (''''..., \"- ·1 r " 0.( ... ; t _.,< '-",.-." ... .,JJl .... ('" '\./ is / Ｒｾ t: ...,-., ;'-', . ,of·... .., -'""oJ
•
, (
"1-ｾ _.-.1. _. " r • \ (I -'0
Ｇｾ,
ＬＱｾ .., i INDIA I ! -''''' JLv 1 I I .' - - ) , ." t \ .'\.. '" ｾＮｲ \ -ｾＩ ｾＬＮ｟ .. ( • • r ｾ _ , BANGLAOESH-'---r:---
r". .,' ... Kunmln.t'｟ｾ I 16 I . ｾ I , / " J •Clnlon I ｾＧ［ '., .e:«, -c: ｾ ｬｾﾷ .r·_·...
I / - / ' - Hon" Koo. BURMA ... ,VlfT .... r ... " . , NAM -'-
\ ._ --1,1/\0<; , 40 30 20PEOPLE'S REPUBLIC OF CHINA
DISTRIBUTION OF PERMAFROST AND SEASONAllY FROZEN GROUND
(j\ 35 45 40
-\
-\'
ISOLATED PERMAFROST ALPINE PERMAFROST CONTINUOUS PERMAFROST ZONE IN THE PLATEAU ISLAND OR ISOLATED PERMAFROSTDISCONTINUOUS ZONE CONTINUOUS ZONE
HIGH LATITUDE PERMAFROST
HIGH ALTITUDE PERMAFROST
SEASONALLY FROZEN GROUND
_ _ SOUTHERN LIMIT
es
§I
§
IDIIIIll
rnn
IIIIIlIII
• Beijing+
+
+
-l-MONGOLIA-l---
--..-."
ｾ
Chengdu+
<,
/ ' __
+
I
?/
'--,::>
/
ｾＬＮＯ+
o
1000 I , I , , , , , I I I km.,.
..,.. 3525
30 45 40 100 110 120 BR 6493-4 ,MAJOR MOUNTAIN RANGES IN THE
PERMAFROST REGION OF CHINA
A. XIAO HINGGAN LING
B. OA HINGGAN LING C. ALTAY SHAN --.J O. TIAN SHAN E. BOGOA SHAN F. ALTUN SHAN G. OlliAN SHAN H. KUNLUN SHAN
I. DAYAN HAR SHAN
J . HOH XIL SHAN
K. TANGGULA (OANGLA) SHAN
ｾ L. NYAINOENTANGLHA SHAN M. HIMALAYA SHAN !;O ｾｯ 70 _ . 3 0 JAPAN
'#
1)r;;
ｖｬ［ｴｦｦｩ｜ｬｯｾｴｯｬ＼ OR 6493-5 ＱｾＰ no 170 170';'1-'-'"
,. ｾＧＮ,
Kh'h:ooV<k , .... -"..
A " - - -r-/ B ,_,/ I .' A lIj 1._·..., i • " ..,hin . - . \ \.",,-... 1ft 110 110 '" • UI'n A.tnr .I,k"hk ｾ 100 u.ss.n. 100-
. . / !Ill , ... J 110,
r>
r " 8 Jr-·
Ji.
"0"'00"
,._"
_
,
. 0 '-. " "''I
I rｾ
• ＮｉｊｾＢ
" /._v,
• _ . - , 1 J _... E , )_.-.- »: i ,.-'-'
- ' ,
-
"'
..
'
'
" ' ".-,.
. , G \ I Ii
Fi..'
ｾｉ ｾ
. : ' ',70Ｂｬｾ
. . - _.AN _ _ . " _ , I " ,vvv
y v - I ,ｾ
I I t, 21 " \ - 1--. L _ .... ;' I · I I I -' I " - - •Ｆｾａ
- " . Goln"'d \ . 1..' _ _ \ __ V\JVOI"""" • "''\oCVL.o ' . / , / , , , <, "-I I I .n,hout - - t ' , s \ 13 " -' 23 ...ＢＧｾ
ｾ
• .I -ＧｾＧＬ
, / _ "'" _, \ ,I \ ' " e -.,( " '. . . '" ,"-",.;\ . / -v 6 -c , ) _. .I , ' 1 4 ) - ' ) £:h.nqdu -'ＯＢＭＬｾＮ
\ • r _ ' - _ｾ
_ \ 25..,....-
..
-{'.
/ \ • Lh .., "'"V I r "\ . / 24 1 __ .., . .... (N '-I 15 , ;'Ｎ［ＢＮｾｾ
.
ＭＺＢＡｾ •, '-.
....ＮＢｊＮｾＩ
"
,ｾＬＭＬ
I ,I ' / ' j . . " -> "! ( ,- 10ｾ
( ,ｾ
.... < ) - '. _. - ..1.... / , \;..., .I l'" 1ｾ
_-.I _, ' - ' , INDtA / - ( , ' ' ' 'ｶｾＬ
_
.1" - - ) I ,. 7 . , t' - I 16 Clnton . . . I .... ' " , . Kunmonq "> " JＮｾ
BANGLADf5H - r fｾ
, .ｾ
.r....
( - /
Honq Knnq I "" I . 't ._.... I i,ｾ
. , :. f'. vu r/'"1
....
ｾ I.... _. ' " . BURMA ｾＮ｜ＬＮＬ _ ,NAM 1/100; I,
INDIA I , I , I ! I I I I t o km 1000rForl.F'S RFPUAlIC OF CHINA
r r - , ' I L Z ,1- ... <0{ " ""J' . :ti' "So4 ｾ i' ｾＧｦｬ \..i <I( '" r. . n . ; > , I V 30 40 20 __
THIRTY YEARS OF PERMAFROST RESEARCH AND ENGINEERING IN CHINA
CHEN Shiaopio, TUNG Puoliang
(Lanzhou Research Institute of Glaciology and Cryopedology, Academia Sinica)
WING Jinkang
(Railway Dept., Science Research Institute)
ZEOU Changqing
(Heilongjiang Research Institute of Cryogenic Engineering Science)
The thirty years since new China has been established has been an important ｰ･ｲｾｯ､ for the serious development of permafrost research and engineering applications. It was also important to the rapid progress of the study of permafrost from its formative stage.
During the 1950' s , many projects involving basic construction and engineer-Ing had contributed considerable data and engineering experience for China, especially in the forestry resources development in the Da Hinggan Ling Mountain Range and the construction of the Qingbai-Xizang (Tibetan) Highway. From the late 1950's to the mid 1960's, the public departments working on railways, highways, irrigation, construction, scientific research, forestry resources, coal mining, and many universitites followed each other in establishing corresponding research institutes for the study of permafrost. This started the systematic and scientific investigation, laboratory simulation, and on-site research of multi-year permafrost in the Qinghai-Xizang Plateau, the Da Hinggan Ling Range and the Qilian Mountains, as well as seasonally frozen soils in the Northeast. The result was the formation and rapid development of Chinese permafrost studies.
In the 1970' s , the combined exper iences and knowledge gathered from
projects in the Qinghai-Xizang Plateau, the Da Hinggan Ling Range, the Tian
Shan Railway, the oil supply pipeline from Golmud to Lhasa, mining operations in the Qilian Mountains, basic construction in the north, and the opening of
freeze-drilled wells gave the study of permafrost a more systematic and
scientific approach to investigations than ever before. Laboratory modelling
and practical field construction experiments brought out many related
construction specifications and handbooks. The study of permafrost in China
has become an independent academic discipline including the study of common
frozen soils, their physics, dynamics and permafrost engineering aspects. In
1978, China attended the Third International Permafrost Conference (in Canada) to present papers and engage in discussion with the other participants.
This article reviews the general progress of permafrost research and
engineering applications over the past 30 years in China. The authors are
grateful for the many uses and references of the yet unpublished materials and data that belong to fellow researchers.
COMMON PERMAFROST (FROZEN SOIL)
The study of permafrost deals with frozen soil formation,
distribution, thickness, temperature fluctuations, development trends and all
the associated physical and geological phenomena. The study of permafrost
also involves research of the inter-relationship between permafrost and the
natural geographical environment, as well as its effects on engineering. It
provides scientific evidence to develop and carry out construction work in the
area of permafrost. It also represents the foundation of permafrost
engineering theories.
Research shows that the distribution of multi-year permafrost in
China is mainly in the Qinghai-Xizang Plateau, the Da Hinggan Ling Range,
Qilian Mountains, Tian Shan and Altay Shan Mountains and mountainous areas of
..
Tung Priliung and Zhore Yuwu ) , and occupies over 22% of China's total area.
Seasonally frozen soil spreads evenly to the north of Changjian (Yangtze)
River and to the vast territories to the northwest and southwest. As a
fostering area for multi-year permafrost, the Qinghai-Xizang Plateau has the
highest altitude, largest area, greatest thickness and the lowest temperature
among all the low latitude multi-year permafrost areas of the world. Its area
is about
ＱＮｾＹ
x 106 sq.krn. and represents about 10% of the total areaunderlain by permafrost in China.
According to the Yakeshi (Yuguit ) Forestry Resources Exploration &
Design Institute and the Lanzhou Glacier and Permafrost Research Bureau of the Chinese Science Institute, the multi-year permafrost of the Da Hinggan Ling Range has distribution, thickness and temperature characteristics that follow
natural geographical variations in latitude. Starting from the south and the
southeast, moving to the north and the northwest, as the latitude increases, the continuity of the permafrost zone increases giving the permafrost a lower
temperature and a greater thickness. Continuous lDulti-year permafros t is
mainly distributed in the northernmost parts of the Da Hinggan Ling Range
where the annual average temperature is lower than _50C, and the thickness
of the permafrost is generally between 50 to 80 metres. Permafrost thickness
may exceed 100 rn in some areas. The mean annual ground temperature is
generally between _10 to _2 oC and it can ｾ･｡｣ｨ _3°C or low€r. If
continuous permafrost is defined as having an areal extent greater than 80%
perennially frozen ground, then the southern boundary of permafrost would
basically be close to the isotherm where the annual average temperature is
_50C or the annual average ground temperature is _2oC. However, land form,
geology and natural geographical environment cause deviations. In some
places, the southern boundary of continuous multi-year permafrost does not
follow the isotherm of _50C annual average temperature. In the Da Hinggan
Ling Range, it has a sou thern boundary with its wes tern portion starting at
the Ji La Lin, Mordaga and the Telbur area. The boundary reaches the Gen
River, goes to the north of Ku-Zi Lin Chang and passes the main ridge of the
Da Hinggan Ling Range, the tributory ridge of the Yilehuli Mountain Range
(Amur River) and the area of Mohe. For the sporadic distribution of islands of frozen soil, the western portion of its southern boundary starts to the south of Ja Laid Wong and Man Chou Li, reaching the west of Xin Barag Zuoqi. The eastern portion starts at the area of Wu Cha Go and enters the Greater Da Hinggan Ling Range by the eastern slope of Pu Te Hagi, Ne He, We Wu and the north of Bei-An, reaching the Lesser Xiao Hinggan Ling Range by the eastern slope of Pu Te Hagi, Ne He, We Wu and the north of Bei-An, reaching the Lesser Xiao Higgan Ling Range at Qing An and to the north of Tien Sheng Tih Li and Nan Chiu. All these areas have sporadic or patchy permafrost distribution.
According to the research of the China Science Institute's Lanzhou Glacier and Permafrost Research Bureau, the Scientific Research Institute of the Railway Department and Beijing (Peking) University, the following outlines the distribution of permafrost along the Qinghai-Xizang Highway. Sporadic distribution of permafrost has its lower northern boundary on the northern foothills of the Kunlun Mountains reaching the eastern section of Xi Da Tan. The al ti tude reaches 4150 to 4200 m above sea level and the annual average temperature is about _20 to _30C. Continuous multi-year permafrost in this region has its lower northern boundary at the northern slope of the Kunlun Mountain, reaching westerly to the northern exit of the Lien Sen Valley with an altitude between 4350 to 4560 m and an annual average temperature of about _uoC. The lower southern boundary of the continuous permafrost here starts to the north of AMDO, with an altitude about 4780 m and annual average temperature between _3.50 to _4oC. The lower altitude of permafrost distribution is 4640 m in the area going south from AMDO to maintenance area 128 on the Highway. The southern boundary of the sporadic distribution of permafrost basically matches the isotherm of _20 to _2.SoC annual average temperature.
While the distribution of multi-year permafrost on plateaus is controlled mainly by altitude, there is also a definite regionalization. Thus, going south, following the decrease in latitude, the lowest altitude at which sporadic permafrost exists will increase and the thickness of the
,.
multi-year permafrost will decrease accordingly. In general, at the same altitude, with each degree decrease in latitude to the south, the average ground temperature increases by O.gO to 1.OoC.
The condition in the Qilian Mountains permafrost can be divided into the central region, such as the Muri Basin where continuous multi-year permafrost reaches a general thickness of 60 to 80 01. Exceptions to this include places where rivers merge or come under the effects of water from deep bedrock fissures, or in areas of over-all thawing in the bed of the Muri River. Also, on bare sunny slopes, this thickness can shrink to 30 m. The mean annual ground temperature here is between _60C to -2.30C. In the Jiang Che Basin, the continuous permafrost reaches 50 to 90 m, except at the thaw areas near major rivers and streams. The annual average ground temperature is between _1.00 to -1.70C. There is a clear vertical regionalization in the Re Shui area situated below the lower boundary of the permafrost zone. Above an altitude of 3780 01, there is a discontinuous distribution of permafrost. Below 3480 m is an area of seasonaly frost action.
Based on the data collected on permafrost, a map of its distribution in China had been completed on a scale of one to ten million (Glacier &
Permafrost Burea-..l). Also, another permafrost distribution map on a scale of one to 20 million is available for the north eastern part of China (Ya Ke Shih Forestry Resources Exploration & Design Institute, Glacier & Permafrost Bureau and the Third Design Bureau of the Railway Department).
Initial research shows that permafrost in the northeast of China was formed in the Da Li (Yunnan) glacial age of the late Pleistocene Epoch, and it varied in the time of the Recent Epoch. Compared to the environment of the periods when it was formed, it is now in its degeneration stage. The mu l ti-year permafrost in the Qinghai-Xizang Plateau is a product of the icy condi tions in the glacial and inter-glacial ages of the Tertiary Period when the plateau rose violently. At present, the multi-year permafrost belongs to the Jung Bi Shi stage of the Chomoulungma glacial age, (an equivalent of the Wa Li glacial). Its area was increased in the Minor glacial age. Its absolute age is 23500
ｾ
1200 years according to Cl 4 tests performed on sand and gravel wedge intrusions found in the areas where major rivers flow. Today, the permafrost on the plateau is in a comparatively stable state.The phenomenon of frozen soil is widely distributed in every
permafrost region in China. At present, research has begun on domes, rock
glaciers, underground ice, ice cones (pingos and pa.l sas ) , structural soils,
mud slides, thaw slides, thermokarst ponds, boulder pavements and granular
soil deposits to initially clarify their formation process, type, distributior.
and development. These features can also provide important evidence for the
research of palaeoclimatology and palaoeogeographica1 environment. In the
Greater Da Hinggan Ling Greater Range, a type of dome with a spring thaw
nature has been discovered. Also, in the Quinghai-Xizang Plateau, massive
domes of a discharging nature have been observed.
Apart from these, the use of flora and fauna features to classify
permafrost characteristics and structure had yielded initial results along the Qinghai-Xizang Highway and Qi1ian Mountains.
Wi thin the technology of permafrost exploration and survey, apart
from the application of drilling and trenching, geophysical prospecting and
survey methods are rapidly developing. The most widely used methods are
electromagnetic exploration using D.C. resistivity, the use of surface seismic methods in shallow strata of frozen soil, and the application of a radioactive
radon gas survey method. Also, preparations-are now in progress to use radar
to measure and test the thickness of frozen soil layers. At present, physical
explorations are supplemented by small amounts of drilling. Such work can
determine thaw depths, permafrost cover depths, underground ice cover depths
and their thickness. Aerial and satellite photograph interpretation and other
similar remote sensing techniques are also beginning to be used.
THE BASIC NATURE OF PERMAFROST PHYSICS AND DYNAMICS
Systematic research into the nature of permafrost physics and
dynamics began in the 1960' s , Each of the main research units possessed
cryogenic laboratories, fixed position survey stations, and substations.
Research included the formation of permafrost and ice; their structure density
and water content; the coefficients of heat and temperature conduction of
temperature for super-cooling and freezing soil; the rate of electrical
conduction of frozen soil; the transmission of ultra sonic waves in frozen
soil; the segregation of water when soil freezes; swelling force of freezing
water; the magnitude of frost heave; hydrostatic pressure in fissures and
holes; the settling of frozen soil and its thaw settlement under load; the
adfreeze strength between frozen soil and foundation construction materials; the shearing and compression resistance of frozen soil; the bearing capacity of frozen soil; and variable compressibility of frozen soil.
There is much evidence to show that when soil freezes, the
re-distribution of pore water forms frozen structures causing very unever.
spacial and linear distributions of density and water contents. Such
characteristics are very important when carrying out engineering evaluations.
The existence of unfrozen water in frozen soil is the main reason for
the unstable nature of the physical and dynamic properties of permafrost.
Presently, experiments have provided the relationship between unfrozen water
content and temperature exhibited in clay, boulder clay, silt and sandy
soils. The initial freezing temperatures of typical soils have also been
determined.
Through systematic experiments, estimates of the coefficients for
specific heat, heat conduction, and thermal conductivity of typical soil types
in some areas have been thoroughly determined. Also, calculated values of the
above thermal properties under different dry density and water content
conditions in soils had been established.
Experiments into the electrical conductivity of frozen soil shows
tha t it possesses a much higher degree of resistance than thawed soil due to
ice in the soil pore spaces, which decreases the mobility of ions. This
physical property is the basis of electrical methods of exploration for
underground ice and permafrost. In engineering, this property is also
In practice, it has been shown that when soil freezes, its pore water
migrates mainly when it is still in a liquid state. In clay, osmotic and
capillary suction are the main moving forces. In soils of a larger grain size
than clay, pore water is moved by pressure under hydraulic gradients as
freezing occurs. When the seasonal zones freezes, the main frost heaving zone
is at about two-thirds of the frost depth. This property is very important
when foundation cover depths have to be determined.
At present, values for the tangential frost heave forces have been
compiled for typical soil types for reference. In studying normal frost
heaving, it has been discovered that heaving decreases with an increase in the contact area between the foundation structure and the soil, rising towards a
certain limit. Also, it decreases with increasing depth of foundation cover.
Furthermore, experiments have shown that horizontal frost heave forces have a magni tude several times to tens of times greater than normal soil overburden pressures.
Frost heave potential is now classified according to the gradation of soils, their water content, and the distance from the frost zone to the water table.
Since the early and mid 1960' s, the thaw set tlemen t properties of
frozen soil have been studied. Based on systematic experiments, the
settlement properties of typical frozen soil types when they thaw have been
established. Also the relationship between thaw settlement, dry density and
water content have been established. Furthermore permafrost has been
classified according to the degree of settlement when thawing occurs.
Many laboratory and field experiments have investigated the adfreeze
strength between frozen soil and different foundation materials. The
relationship between permafrost soil type, water content, ground temperature,
the rate of loading and foundation materials has also been studied. There has
been analysis of ice thickness when re-freezing occurs around the perimeter of
a foundation. Also, the long-term adfreeze strength between typical frozen
soil types and concrete, wood, and steel foundation structures has been
The magnitude of shearing resistance has been observed at the frost line where freezing occurs. By experiment, it has been shown that the point of lowest strength does not occur at the frost line, but at a definite distance from this level, within the stratum of the thawed (soft) soil.
In addition, experiments are proceeding on the compressibility of frozen soil. Research is also being conducted into the stress and strain properties of frozen soils, the yield strain, the modulus of elasticity, water content, soil temperature, the rate of loading and their interrelationships. In the 1970's, experiments in static load and the nature of creep variability of frozen soils were conducted along the Qinghai-Xizang Highway. Also, there were laboratory experiments on permafrost flexural resistance and corresponding formulae were established. Th€S€· have suggested the load capacity of different typical soil types.
In the ＱＹＷＰｴｳｾ experiments were done on models of single pile structures under vertical and horizontal load. Also, in the Qinghai-Xizang Plateau, experiments were done on dynamic pile driving, insertion pile driving, dynamically cast-in place piles (Franki pile) and single 'Pile load capacity. Valuable evidence and results were obtained to solve problems of concrete strength at sub-zero temperatures and other construction techniques.
PERMAFROST ENGINEERING
The main problem encountered with all types of civil construction projects in the northeast, north and northwest of China involving seasonally frozen soil is that when soil freezes, water is attracted causing heave.
Road construction research first began in the 1950's. In the 1960's conventions for the prevention of frost damage to roads allowed the exchange of experiences throughout China. In order to describe the hydrological and geological regimes of the different roads, the research units of the Transportation Department developed equations to calculate the ice segregation rates for road subgrades. Also, successful experiences were summarized relating to lime-concrete base layers, the use of lime and concrete piles to improve water temperature at the road subgradej water drainagej temperature maintenance; and soil improvement. These became the focal point of measures
The Railway Departments of northern China have been using salt to
depress the freezing poin t o f water gathered at the foundations of tracks
passing through wet areas. The added salt increases the salinity of the water
in the soil thus decreasing the depth of freezing. This measure can ei ther
eliminate or lessen frost damage.
It has been shown in practice that foundations for small buildings in
areas of seasonally frozen soil must have a foundation cover that is 3 to 4
times the depth of seasonal freezing so that stability against heaving can be
ensured. When anchors are installed on a pile below the deepest freezing
level, frost heave can be eliminated or lessened. Also, repeated experiments
show that when bitumen grease or surface lubricants are smeared around the
pile, over-all prevention against frost heave can be achieved. This method
can decrease the magnitude of frost heave by over 90%.
Research has shown that for hydraulic structures constructed in
regions with large areal deposits of clay, the only way to prevent frost heave
is by the USE ::ean sand and stone fill in flood gate and culvert
foundations which are constantly saturated with water. Impoundment must be
done when the lower portions of the backfill are relatively free-draining, so
that excess water produced by freezing and volume expansion Can dissipate
under a hydraulic pressure gradient. I t is therefore suggested that water
storage compartments be installed on both sides of a structure under
seasonally frozen strata. To eliminate frost damage, ducts should be placed
at the bottom of the base layer and of the water storage compartments. To
minimize the effect of frozen soil on structures, bar shaped supports can
adequately resist frost heave and provide stability in small flood gates.
Water stored in front of the gate and in the energy dissipating pools in
winter time can also greatly reduce the depth of freezing and can control
distortion caused by freezing.
In sewer constructi on, many units use basal layers of sand under
condrete lined structures. This works quite well in preventing frost heaving
on the side slopes. In areas which lack coarse support materials, asphalt
matting or plastic membranes and other similar soft anti-seepage structures can be used to allow for better adaptability to uneven heave and distortion.
The
"TT"
shape d anti-seepage concrete slab used by the Shenxi Water Works Bureau controls frost heave because the cross rib around the slab comes into contact with the soil and significantly increases the unit pressure. If this contact pressure can be extended to the maximum load capacity of the foundation soil, the result would be even better.A more suitable support structure used in areas of seasonally frozen soil would be the bin-type earth retaining wall which readily drains water. This is used in the Wei Hua district in the Heilungjiang region.
The work on anti-seepage core insertion involves a very difficult construction procedure in winter repairs to earth dams. As early as 1956, the Water Works Bureau of Heilungjiang had successfully used excavated frozen soil to maintain the crest elevation depending on the amount of settlement. When the water inside the storage compartments settles and melts, it becomes a natural and complete anti seepage cover. The result has been successful in many places and over many years.
After many on-site investigations of industrial and civil ｳｴｲｵ｣ｴｵｲ･ｳｾ
it has been firmly accepted that remnants of frozen soil strata can remain under foundations due to the fact that frost heave is controlled by the rythmic nature of the main heaving zone and the additional load. Corresponding formulae have been established to determine the smallest depth of cover for foundations buH t in areas of seasonally frozen soil. As a result, foundation building time has been shortened. ｔｨ･ｳｾ r-esur ts are now included in the relevant specification guidelines. Furthermore, techniques such as the use of sand and stone backfill around piles, maintenance of ground temperature, or the use of blast expansion short pile foundation to eliminate foundation frost heaving have given good results.
In areas of permafrost, the development of underground ice confronts all construction work with frost heave problems, particularly in warm structures. However, thaw settlement in the frozen foundation soil is even more important. Also, many other physical and geological phenomena adversely affect such structures.
For these reasons, the initial problem is to obtain predictions of the temperature fluctuations over many years after construction is completed
in permafrost. Temperature observations, practical analysis of construction
engineering, the establishment of thermodynamic simulation theories and
laboratory model experiments have suggested methods to calculate the thaw zone
beneath foundations for warm structures. Also, formulae for calculating the
maximum thaw depth involved in road subgrade foundations and drainage works
have been established. These provide additional reliable evidence for
forecasting and controlling temperature fluctuations in permafrost existing
under structures.
Road construction experiences gathered in the Greater Da Hinggan Ling
Range and in the Qinghai-Xizang Plateau have shown that when construction
passes through multi-year permafrost, especially in very icy areas, the rule
of thumb to "maximize filling and minimize excavating" must be firmly
followed. This is done to maintain the foundation soil in a frozen state as
much as possible. In the Qinghai-Xizang Plateau and even down to the lower
boundary of permafrost at Re Shui, the depth to the permafrost table will rise
significantly as long as drainage is properly provided for after the
construction of road embankments. The unstable state of the frozen soil in
the Greater Da Hinggan Ling Range, however, causes the permafrost table to
drop after the road embankment reaches a certain height, because of heat
stored during construction. The sub-base of roads, zero cross section and low
embankments that cross very icy sections should all use temperature
maintenance or the use of embankments of non-frost-susceptible fill. Many
years of practice shows that the use of small cross sections to maintain the temperature of the sub-base in very icy sections in the Qinghai-Xizang Plateau is economical and reliable.
Through the accumulation of experience over the years, there is now a rather complete set of methods to prevent and cure such undesireable physical
and geological phenomena as swelling domes, ice cones and slope instability
due to thawing. The spring thaw swelling domes in the Greater Da Hinggan Ling
Range can be eliminated by the method of "drainage and pressure reduction by
weep hole perforation". In road subgrades and underground drainage weep hole
outlets under temperature maintenance used in tunnels, ice cone blockage can be prevented by the use of temperature maintenance devices of a conical shape.
For the construction of bridge culverts, the use of cast-in-place
concrete piles has been generally successful in many places. This method
fully utilizes the adfreeze strength between the pile and the perennially
frozen soil as the support for the foundation load, and the resisting force
against frost action in the seasonal frost zone. The use of pre-fabricated
concrete structures has also been used recently.
The designs of civil structures in multi-year permafrost areas are
mostly based on the principle of gradual thawing of frozen foundation soil,
paying attention to the logical placement of heat sources so that the
foundation under the structure settles as uniformly as possible. In the past
ten years, the use of earth cushioned foundation sub-bases, layered ring-beam foundations, and light weight wall structures of areated concrete have used.
The addition of ventilating ducts in the base layers has also begun. All
these methods have definite benefits. In very icy sections, elevated
foundations with air vents are commonly constructed for structures with high
heat sources. Practice shows that in the more stable central regions of'
permafrost, this method can help keep the foundation soil in a frozen state.
There is general use of elevated pipelines or duct work with
temperature maintenance for water supply construction in permafrost areas.
Also the use of heat in supply wells or along pipe routes achieves very good
results.
Achievements in plateau mining construction projects have resulted in
the accumulation of valuable experience in resource development in
permafrost. There is wide use of freeze-drilled well methods in the northern
and eastern plains. There is also rather systematic data collected on heat
transfer along the walls of wells and on pressures during freeze-back.
In recent years, such departments as public works and mechanization
have been following machinery technologies research related to excavation,
drilling, pile driving and blasting methods in permafrost. This research has
DISCUSSION ON THE TRENDS OF RESEARCH
Modern technologies in geophysical exploration, satellite photograph analysis, remote sensing and thermodynamic methods are presently utilized in the research and study of permafrost to more rigorously investigate the basic permafrost properties such as distribution, thickness, temperature conditions,
material make-up, structural fabric and underground water migration. A
permafrost map of China on a larger scale can be produced. Further steps can
be taken to investigate the formation and development trends of the low
latitude Qing Zang Plateau multi-year permafrost. Also, its effect on the
natural geographical environment of China should be studied.
Further research steps are needed in the study of basic physical,
dynamic and periodic properties of permafrost. There is a particular need to
strengthen research into the relative water content of frozen soil and the
process of ice formation. The basic mechanics and rythms of water migration
should be investigated through observable and measurable phenomena. Also,
more ｲ･ｳ･｡ｲｾＺ s:Jld be directed to the flow, alteration and mechanical
processes of permafrost. Furthermore, experimental techniques and modern
installa tions should be reinforced, and long-term fixed position observation
stations should be widely established.
To satisfy the engineering and construction needs in permafrost
areas, there must be accurate forecasts relating to the effects of human
construction activities on the area. Predictions on the depth and development
of soil freezing and thawing under structures are also needed. Construction
experiences inside and outside of China should be summarized. Practical
engineering experiments should be started that are appropriate for local
conditions, and timely exchange of experiences and results should be
broadened. There is also the need to strengthen prospecting and survey
methods in permafrost, mechanization of permafrost construction equipment,
development of reasonable structures and architecture for cold areas and
There should be an early start in agricultural studies in permafrost, together with ecological studies and environmental protection research.
There is still much to do and a long way to go for researchers in the vast technology relating to permafrost. We must keep sight of China's four major national goals and take aim at progress towards a world standard. We must learn humbly, work diligently and then there is every reason to believe that we can rank as a leader in permafrost study among other world leaders in the subject by the end of this century.
BIBLIOGRAPHY
(Titles of Documents and Publications can only be translated literally.)
1. Xin Kueite, Jen Quij ia. "Dis tribution of mul ti-year perma fros t in northeast China". Geodogy Knowledge, October 1956.
2. Jen Quijia. China" •
ｾｎ･ｷ data relating to multi-year permafrost in northeastern Hydrological Geology Engineering, May
1957.
3.
Railway Dept., Third Design Bureau, edited. "Engineering geology inmulti-year permafrost and railway construction". The People's Railway Publishing Bureau, 1958.
4. Zhon Yuwu, Tu Junghuan. "Initial survey of the Qinghai-Xizang· permafrost". Scientific Communique, February 1963.
5. Zee Yafeng. "Five years of glaciology in Chinatt
• The .study of
Permafrost and Desert Hydrology Research Scientific Communique, March 1964.
6. Chinese Science Institute, Geography ｾ･ｳ･｡ｲ｣ｨ Bureau, Glacier and
Permafrost Study Office. "Permafrost survey along the Qinghai-Xizang Highway". Science Publishing Bureau, 1975.
7. National Basic Construction Committee, Engineering Science Research
Bureau, edited. "Industrial and civil engineering foundation design specifications". Engineering Industry of China Publications Bureau, Beijing, 1974.
8.
Chinese Science Institute, Lanzhou Glacier, Permafrost and Desert Research Bureau, Permafrost, Science Publications Bureau, 1975.9. Railway Dept., The First Design Bureau. "Handbook of Railway Engineering Geology". The People's Railway PUblishing Bureau, 1975.
10. Chinese Science Institute, Lanzhou Glacier, Permafrost and Desert
Research Bureau, Collected Periodicals, No.1, Scientific Publishing Bureau, 1976.
11. Railway Dept., Science Research Institute, People's Republic of China's Liberation Army, 59244 Troop, Heilungjiang Cryological Engineering Science Research Bureau. "Pile foundations load testing in multi-year permafrost research laboratories". Engineering Techniques Communique, (Engineering Structures), Afr. 1977.
12. Chen Chiapuo, Wu Ziwang. "Major experiments and research in the nature of permafrost dynamics (summary)". Address to the Third International Permafrost Conference, 1978.
13. Cheung Guodung, Tung Puo1iang, Luo Xuebuo. "Road embankment experiments in thick layers of underground ice sections under permafrost in high mountains". Address to the Third International Permafrost
Conference, 197B.
14. Railway Dept., Science Research Institute, Road Foundation and
Experiments and Research Group. "Road foundation experiments in thick layers of underground ice sections". Address to the Third International Permafrost Conference, 1978.
15. Railway Dept., Science Research Institute, Permafrost Pile Foundation Research Group. "Experiments in pile foundations in multi-year permafrost areas". Address to the Third International Permafrost Conference, 1978.
16. Railway Dept., The Third engineering design foundations)". The 1978.
Design Bureau, edited. "Handbook of railway techniques, (bridge foundations and ground People's Railway Publishing Bureau, September
17. Ding Tewen. "The calculation of maximum thaw depth and stability time for heat gathering structures in areas of ground foundation thawing". Science Communique, November 1978.
lB. Wang Jiacheung, Wang Shao1ing, Qui Guoching. "The multi-year permafrost along the Qinghai-Xizang Highway". Geography Journal, November 1978. 19. Guo Dungxin. "The sand and pebbles of the Qinghai-Xizang Plateau".
CERTAIN DISTINCTIONS BETWEEN THE PERMAFROST OF THE CHINESE QINGHAI-XIZANG (TIBETAN) PLATEAU ANL THAT OF THE CANADIAN NORTH
by Guodong CHENG
(Lanzhou Research Institute of ｇｬ｡ｾｩｯｬｯｧｹ and Cryopedology, Chinese Academy of
Sciences)
Permafrost is distributed in approximately 2.14 x square
kilometres in China representing one fifth of the total area of the country. In the Qinghai-Xizang (Tibetan) Plateau, the so-called "Roof of the World", permafrost is the highest in elevation and the most extensive in area in the
midd:e and low latitudes of the world. A preliminary estimate indicates ｴｨ｡ｾ
permafrost underlies approximately 1.49 x 106 square kilometres on the
Plateau, or 70% of the total permafrost area in China. In Canada, permafrost
underli-es approximately 3.89-4.92 x 106 square kiloI!l€tres, occupying
ＭＴＰＭＵＰｾ
of the total area of the country. The permafrost in the high-elevation
Qinghai-Xizang Plateau differs greatly from that in th-e high-latitude Canadian
North. The purpose of this paper is to try to make a comparison between the
two different types of permafrost, with an emphasis on the differences between
them in order to better understand the specific characteristics of the
permafrost and better reveal the effect of various geological and geographical factors on permafrost distribution.
There are many problems to overcome when comparing permafrost in the
two countries. At present, the study of permafrost in the Qinghai-Xizang
Platea;.! is undertaken mainly along the Qinghai-Xizang Highway. Since the
Qinghai-Xizang Highway runs through the central part of the Plateau, it
provides a good profile for understanding permafrost conditions in the
Plateau. Although relatively detailed information is available along this
highway, only fragmentary information is available concerning the distribution
of permafrost in other areas. It is possible to make a comparison with
present information but the comparison can only be very brief. Any detailed
comparison can only be made at a later date when more complete information is available.
Distribution of Permafrost
Permafrost is obviously controlled by altitude above sea level. The following table lists values of the lower limit of the permafrost along the Qinghai-Xizang Highway. The table indicates that permafrost distribution, in addition to being controlled by altitude above sea level, also relates to latitude. The lower limit of permafrost increases approximately 100 - 130 metres for every degree southward in latitude. Both temperature and thickness of permafrost on the Plateau relate to altitude and latitude zonation. Generally speaking, for every 100 metre increase in altitude, the mean annual ground temperature decreases 0.5 - 0.60C and permafrost thickness increases correspondingly. By the same token, the more southerly occurrences of permafrost possess higher permafrost temperatures and the permafrost thickness is smaller. Therefore, permafrost of low temperature and great thickness exists mostly in the high-altitude and northern regions of the Plateau such as the Kunlun Snan and Tanggula (Dangla) Shan (Mountain) regions.
Permafrost Lower Limits Along The Qinghai-Xizang Highway
Latitude I N35045' N31056' N31042' N3lo29, N31000 Low-limit Altitude (m) from 4150 4610 4640 4670 4720 Sea Level
In the Canadian North, permafrost is mainly controlled by latitude. Permafrost is present north of the 51oN par·allel. As latitude increases, permafrost changes from discontinuous to continuous in distribution, ground temperatures drop, and thickness increases.
The southern limit of permafrost in Canada coincides roughly with the mean annual air temperature isotherm, and the boundary between continuous and discontinuous permafrost coincides approximately with the
isotherm. zone with zone mean mean can
annual air temperature isotherm which, in turn, relates to the annual ground temperature isotherm. The discontinuous permafrost be divided into two by the _40C mean annual air temperature North of the _40C isotherm is the wide discontinuous permafrost sporadically thawed areas or "islands". South of the -li°C isotherm is the scattered permafrost zone where permafrost occurs mainly in
peatlands on northern slopes and heavily shaded areas. 2)
The mean annual air t€mperature at the lower permafrost limit on the Qinghai-Xizang Plateau is approximately -2 to ｟ＳＰｃｾ (i.€. about 1 to 20C lower than the mean annual temperature at the southern limit of permafrost in Canada) and close to the annual mean temperature at the lower limit of permafrost for high mountains in the temperature regions of the northern hemisphere (e.g. Fujii, et al.). Fujii et a1. (197-) beli€ve that this difference is due tu the higher amount of h€at received by the ground surface in high mountains than in high-altitude regions under the same temperature conditions. The ｾ･｡ｮ annual temperature at the boundary between the continuous and discontinuous permafrost zones is apprOXimately -3.5 to Tbis is close to the isotherm which divides the discontinuous permafros:' zone into two subzones in canada. ｈｯｷ･ｶ･ｲｾ in the discontinuous permafrost zone on the Plateau, permafrost islands are mostly located in wet areas rether than beneath dry peatlands, as in areas of sporadic permafrost in Canada. In view of the obove, the differentiating criteria currently in use
in Canada are not applicable to the Qunghai-Xizang Plateau.
At the southern permafrost limit, or the corresponding -SoC mean annual ground temperature isotherm, permafrost is 60 to 100 metres thick in Canada and 2S0 to 300 metres in Siberia, suggesting that permafrost in Siberia is thicker than in Canada. Brown (1966) believes that this is mainly attributed to the glacial history of the two continents. During the Pleistocene, the vast majority of Canada was covered by ice-sheets and glaciers. Beneath the continental ice-sheets, permafrost was limited in thickness due to basal ice temperatures which approached zero. When ice
retreated, permafrost beneath lakes and seas probably disappeared and migh; not have formed again until the retreat of post-glacial water bodies. In Siberia, on the other hand, small ice-caps formed during the Pleistocene and ground. surfaces not covered by ice were exposed to very low temperatures under periglacial climatic conditions. This resulted in thicker permafrost in Siberia than in Canada under a similar mean annual ground temperatures.
The same reason may be used to explain the difference between permafrost in the Qinghai-Xizang Plateau and the canadian North. In the Qinghai-Xizang Plateau the thickness of permafrost corresponding to the -SoC mean annual ground temperature is estimated to be 120 to 160 metres, (Le. greater than that of Canada but smaller than that of Siberia). This is possibly because, during the Quaternary era, there were no unified ice sheets on the Qinghai-Xizang Plateau but merely piedmont and valley glaciers, since moraines are presently found only in the mountainous and piedmont areas. Therefore, permafrost in the Qinghai-Xizang Plateau is thicker than in Canada given the same mean annual ground temperature. However, due to later uplift, younger age, and less degree of exposure of the Qinghai-Xizang Plateau than Siberia, the permafrost thickness under the same mean annual ground temperature is smaller for the Qinghai-Xizang Plateau than for Siberia.
Temperature of the permafrost along the Qinghai-Xizang Highway is characterized by low annual range (average 23 to 26oC) and high daily range (approximately 130C on average). Under similar conditions, this makes the active layer relatively shallow, and the yearly depth variation smaller, for permafrost in the Qinghai-Xizang Plateau than in the Canadian North. The annual temperature range near the lower limit is smaller than the annual temperature range at the southern limits of continuous and discontinuous permafrost at high altitudes. These are the general characteristics of permafrost in high mountains and plateaus.
The ｧ･ｯｴｨ･ｲｲｲｾｬ heat flow is an important factor controlling the distribution of permafrost. Based on information from Dr. A.S. Judge, the value of the geothermal heat flow in the Canadian North varies from 0.8 x
-6 2 -6 2
10 cal/cm .sec to 2.0 x 10 cal/cm .sec according to the geological age, radioactivity, and geological structure. The North Pole Tableland, where no coastal activities have occurred since the Precambrian era, has the lowest geothermal heat flow value. But, in the Sverdrup Basin which experienced activities by intrusive rocks during the Tertiary period, the geothermal heat flow is higher. Correspondingly, in the Precambrian rocks with little or no soil in the northern part of Baffin Island, Boothia Penninsu1a, and Victoria Island and in Palaeozoic rocks, such as dolomite and pure crystal line sandstone having high heat conduction values, permafrost thickness in the greatest, possibly exceeding 1000 metres. The permafrost thickness in the
(talus) sediments in the Sverdrup Basin, however, is very limited.
At present, data on the geothermal heat flow in the Qinghai-Xizang Plateau is still very meager. As the Qinghai-Xizang Plateau has a short uplift ｨｩｳｴｯｲｹｾ in the frequent and recent structural movements, and frequent igneous intrusions, relatively high geothermal heat flow values can be expected. Already discovered along the Qinghai-Xizang Highway are some thawed zones caused mainly by structural terrestrial heat. For instance, the Buqu He (river) on the northern piedmont of Tanggula Shan, which crosses a NW700
-oriented fault, forms the Buqu He fault valley to the south and the Buqu He gorge to the north. In the valley, fractures are developed and the terrestrial heat is abnormal, resulting in the presence of many hot springs with water temperature generally between 25 - !lOoC and up to 700C in some localities. Due to the effect of the springs and the structural terrestrial hea t, belt-shaped thawed zones aligned along the strike of the fault occur. The Buqu He ( river) in the northern valley section flows in the direction of the structural fracture with relatively larger discharge, which, together with the and terrestrial heat and the water flow, forms a thawed zone beneath the riverbed and the front edges of Terraces I and II.
Slope angle and slope direction determine the total solar radiation the ground surface is to receive, thus also affecting the distribution of permafrost. The Qinghai-Xizang Plateau is highly mountainous and, therefore, the effect is more evident. For instance, slopes on both sides of Xidatan on the Qinghai-Xizang Highway are steep on the south and gentle on the north. At the same depth on the two slopes the ground temperature varies 2 to 30C and the lower limit of permafrost on the northern slope is 100 metres lower than that on the southern slope. In the canadian North, under similar conditions, whith the exception of higher altitude, the effect of slope angle and slope direction is more apparent. For example, some of the east-west valleys leading to the Black River along the Mackenzie Highway in northern Alberta have permafrost on the northern slopes but none on the southern slopes.
Snow cover which affects the heat-exchange between the ground and the atmosphere also influences the distribution of permafrost. In permafrost areas on the Qinghai-Xizang Plateau, precipitation is limited (300-450 mm/year) and more than 90% of the yearly precipitation occurs in the May-September period. The snow cover is limited in thickness, is discontinuous and short in duration due to the dry and windy winter and, therefore, has very little influence on the distribution of permafrost. In Canada, the situation is quite different. Due to heavy snowfalls, long snow-cover duration, and thick snow mantle, snow cover markedly affects the permafrost distribution. For instance, snow deposition on the eastern side of Hudson Bay is particularly heavy in late autumn before the Bay is ice covered, making the southern permafrost limit along the eastern side more northerly than that on the weatern side of the bay.
Vegetation cover also causes a great difference. In the permafrost zone of the Qinghai-Xizang Plateau, there are no trees but mainly perennial herbs. In Canada there are forests in the permafrost zones. Trees such as spruce favour large areas of moss-vegetation cover in there shade. This vegetation cover difference is a possible cause of the greater thickness of the active layer on the Qinghai-Xizang Plateau than in Canada.
Thermokarst occurs in both the permafrost regions of the Plateau and
the Canadian North. In Canada, beaded drainage systems are common due to ｴｨ｡ｾ
by the water.
In summary, the distribution of many permafrost phenomena in the
Canadian North obey latitude-zonal rules. For example, closed-system pingos
are located mainly in continuous permafrost while open-system pingos occur
mainly in discontinuous permafrost. Palsas exist mainly in the discontinuous
permafrost zone. On the Qinghai-Xizang Plateau, the distribution of some of
the permafrost phenomena is closely related to elevation and topography, and
specific types of permafrost phenomena are related to specific types of
terrain. Roek glaciers are distributed in highly mountainous regions above
4900 metres in elevation. Solifluction and mud avalanches occur mainly on
mountain slopes. In river valleys, on flood plains, at passes in the
mountains, in the lower parts of the alluvial flood plains, and at other low
elevations, permafrost phenomena such as pingos, ice-mounds, and thermokarst
lakes develop.
BIBLIOGRAPHY
1. WANG Jia::lheng, WANG Shaoling, QlD Guoqing,
1973:
Permafrast along theｾｩｮｧｨ｡ｩＭｘｩｺ｡ｮｧ Highway, Acta Geographica, vol. 347 no. 17 March.
2. R.J.E. Brown, 1967: Comparison of Permafrost Conditions in Canada and
PROELEMS Or ROADEED STAEILITY IN THE ｃｏｾｓｔｒｕｃｔｉｏｋ
OF AN ASPHALT SURFACE FOR THE QINGHAI-XIZANG ＨｔｉｂｅｔａｾＩ ｈｉｇｈｾａｙ
IN CHINA'S PERMAFROST REGION
by Xuewen ZHU
Scientific Research Group for the Qinghai-Xizang (Tibetan) Highway, Ministry of Communications.
The Qinghai-Tibetan highway is one of the most important
communication links between China proper and Tibet. Owing to the st.eaoi ry
in:re2sing volume of traffl: on the highway, a project to pave this road with
aspna'lt was begun in 1973. The main construction problem to be solved in
connect.a on witt this pr o je ct was how the stability of the roadbed could be
ｭ｡ｩｮｴ｡ｩｮｾ､ as the highway passes theough China's permafrost zone, because over
600 km of the road is on perennially frozen ground.
A::ording to the results of a preliminary survey, over 200 km of the
highway crosses areas containing significant amounts of ground ice. I'nis
causes the most serious problem facing this project: how to keep the paved
highway from being damaged when the ground ice melts. Other important
problems in:lude the prote:tion of the highway from frost heaves and frost
boils and the aocurate determination of the optimum gradeline elevation,
because over 90 percent of the damage occurring to the old Qinghai-Tibetan
road was caused by insufficient elevation of the gradeline and poor drainage. Our research group has investigated these problems over the last few years and
has gained some results which can now be published. It is our hope that any
inaccuracies in the general overview that follows will be brought to our
attention so that we may correct them.
*
(Transla:or' s note : Qinghai was romanized as "Tsinghai" in the phoneticssystem formerly used in China.)
I. The Problerr of Preserving Permafrost
According to studies conducted by the Glaciology and Cryopedology
Institute and other organizations in this field, most of the perennially
frozen ground occurring along the Qinghai - Tibetan highway is rela ti vely
stable. Thus construction projects planned for this area should be based on
the principle of preserving the permafrost. However, the southern section of
the highway either passes close to thawed ground or through areas where only
islands of permafrost occur. But even in this region, where the temperature
of the frozen ground is comparatively high, it is still appropriate to design
roadbeds on the basis of the principles that are used to safeguaro
construction projects in permafrost regions. The reason for this is t.hat
these areas either have high groundwater tables or consist of marshes, swamrs
or other tracts of wet land, so that, broadly speaking, problems of roadbed
stability must also be addressed.
1. Types of Damage Due to Thawing of Frozen Ground and Classificatior. of
Highway Sections According to the Permafrost Preservation Principles Required for Them
Highways constructed in areas where abundant ground ice occurs can
suffer various sorts of damage if care is not taken to ensure that the
underlying permafrost is preserved. If the ground ice should melt, these
highways may slump, frost boils may develop, or other phenomena associated
with frost action in soils may be observed - solifluction, pumping, sliding or
collapse of the roadbed, cracking of side slopes etc. (Plates 1 , 2 , 3 , 4 ) .
Therefore, when designing highways that will pass through permafrost areas
containing considerable amounts of ground ice, certain principles should be
observed in constructing the roadbed. One of these is that, as far as
possible, one should "fill and not excavate". Also, every effort should be
made to leave the natural vegetation cover undisturbed, and newly built
roadbeds should be repaved with asphalt a year or two after the initial
