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第
41
卷第
2
期
2010
年
4
月
中南大学学报(自然科学版)
JournaI
of
CentraI
South University (Science
and
Technology)
水岩作用下岩石亚临界裂纹的扩展规律
曹平杨慧江学良
2
陈瑜马春德
l
(1.中南大学资源与安全工程学院,湖南长沙,
410083;
2.
湖南城市学院土木工程学院,湖南益阳,
413000)
Vo
l.
41
No
.2
Apr.20
1O
摘
要:采用双扭试件,利用常位移松弛法,分别进行自然状态以及水岩作用下大理岩和混合岩的亚临界裂纹扩
展实验,获得
2
种环境下岩石裂纹扩展速率
v
与应力强度因子岛的关系,并计算得到亚临界裂纹扩展参数
A
和
n
。
通过对比,研究水对岩石亚临界裂纹扩展规律的影响。研究结果表明:对于大理岩,其
A
为自然状态下的
8.07X
10
16
倍
,
n
由自然状态下的
48.33
下降到
8.28;
对于混合岩,其
A
为自然状态下的
5
.4
5X
10
9
倍
n
则由自然状态下的
60.20
下降到
2
1.邸,说明对应于同一应力强度因子水平,水作用下的岩石亚临界裂纹扩展速度耍'快:水的存在使
得岩石的断裂韧度
K
1C
明显降低,对于大理岩,自然状态下的
K
1C
为
3.031
6
MN/m
3
/
2
,水岩作用后
K
1C
为
2
.2
070
MN/m
3
尼,下降
27.19%;
对于混合岩,
2
种状态下的
K
1C
分别为
2.0877
和1.
9398
MN/
旷气下降
7.08%
。该实验
结果可为复杂矿岩的稳定性分析提供可靠依据。
关键词:双扭试件:常位移松弛法
7)(
岩作用:亚临界裂纹扩展:应力强度因子:断裂韧度
中图分类号
0342.1
文献标志码
A
文章编号
1672-7207(2010)02-0649-06
Subcritical
crack
growth
of
rock during water-rock interaction
CAO
Ping
1
,
YANG
Hui
1
,
JIANG
Xue-lia
时,
CHEN
Yu
1
,
MA
Chun-de
1
(1.
School ofResources and Safety Engineering, Central South
Universi
纱,
Changsha 410083, China;
2.
School ofCivil Engineering, Hunan City University, Yiyang 413000, China)
Abstract: By adopting the double-torsion load-relaxation method at constant displacement
, two kinds
of
rocks were
tested to get the parameters
of
subcritical crack growth
and
企
acture
toughness
(K
Id.
In order to compare the
p
缸
ameters
of
rocks in different
environmen
饵,
the test specimens were divided into two groups: one group was immersed in
groundwater and the other in
air.
The relations
of
the
s
仕
ess
intensity factor K
1
and the subcritical crack growth velocity v
were obtained by test, and the subcritical crack growth parameters A and n were also obtained. The behavior
of
subcrtical
crack growth in different environments was analyzed. The results show that compared with marble specimens in natural
state
, A increases in 8.07 X
10
16
folds but n
decreases
仕
om
48
.3
3 to 8.28 because
of
the water-rock interaction. And in
migmatite test
, A also increases in 5
.4
5 X
10
9
folds and n
decreases
仕
om
60
.2
0
to
2
1.
86. Meanwhile,
the
仕
acture
toughness K
1C
also decreases obviously due to water effec
t.
The K
1C
of
marble is 3.031 6 MN/m
3
/
2
in air and 2.207 0
MN/m
3
/
2
in water
, and it decreases by 27.19%. And for migmatite, the K
1C
is 2.087 7 MN/m
3
/
2
in air and 1.939 8 MN/m
3
/
2
in water
, decreases by 7.08%, which shows that the water-rock interaction speeds up the subcritical crack growth.
Reliable references are provided by the testing results for studying time-dependent
of
rock stability.
Key words: double torsion specimen; constant displacement load relaxation method; water-rock interaction; subcritical
crack growth; stress intensity
factor;
企
acture
toughness
收稿日期
2009-09-05
;修回日期
2009-11-30
基金项目:国家自然科学基金资助项目
(50774093
,
10972238);
湖南省自然科学基金资助项目
(0
7JJ
6084);
中南大学博士生创新项目
(2009bsxt060)
通信作者:曹平
(1959-).
男,湖南祁东人,教授,博士生导师,从事岩石断裂力学研究;电话
13973128263;
E-mai1:
pcao_csu@tom.com