Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics
As a kind of existing and potential geological disaster at source of avalanche on cliffs or steep slopes, perilous rock has developed in the western area of China widely and it poses a serious threat to highways, railways, pipelines, cities, and mining for a long time. More than ten years of enginee...
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| Опубліковано в: : | Прикладная механика |
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| Дата: | 2013 |
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Інститут механіки ім. С.П. Тимошенка НАН України
2013
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| Цитувати: | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics / H.K. Chen, H.M. Tang // Прикладная механика. — 2013. — Т. 49, № 3. — С. 135-144. — Бібліогр.: 16 назв. — рос. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860000973959725056 |
|---|---|
| author | Chen, H.K. Tang, H.M. |
| author_facet | Chen, H.K. Tang, H.M. |
| citation_txt | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics / H.K. Chen, H.M. Tang // Прикладная механика. — 2013. — Т. 49, № 3. — С. 135-144. — Бібліогр.: 16 назв. — рос. |
| collection | DSpace DC |
| container_title | Прикладная механика |
| description | As a kind of existing and potential geological disaster at source of avalanche on cliffs or steep slopes, perilous rock has developed in the western area of China widely and it poses a serious threat to highways, railways, pipelines, cities, and mining for a long time. More than ten years of engineering experience have shown the necessity and importance to pay our attention to the avalanche sources in active collapse mitigation. The support - anchor combined technique is devoted to the active hazard mitigation measures of perilous rock. This paper introduces fracture mechanics to investigate the design procedure of the support - anchor combined technique. To obtain reasonable design parameters of the technique, both stability assessment criterion and three safety classes of protection engineering for perilous rock is proposed, further, stable analysis methods for various types of perilous rock are established by using fracture mechanics. Abiding by the idea that to improve stability coefficient to a higher level, the support force of structure and the anchorage force of anchorbolt from the support - anchor combined technique are introduced into stability analysis methods established above, which can estimate the section dimension of support subunit and the amount of anchorbolt of the technique. Engineering applications of the technique in thousands of protection engineering have identified the remarkable effectiveness.
Більш ніж десять років інженерного досвіду в західній частині Китаю показали необхідність і важливість уваги до джерел лавин з метою активного зменшення катастроф. Для вимірювання активного зменшення ризику від небезпечних грунтів розроблена об‘єднана методика «опора-анкер». У роботі застосована механіка руйнування для дослідження процедури створення розрахункової схеми об‘єднаної методики «опора-анкер». Для отримання коректних параметрів схеми запропоновано критерій оцінки стійкості і три класи безпеки інженерного захисту для небезпечних грунтів. Далі на основі механіки руйнування розвинуті стійкі методи аналізу для різних типів небезпечних грунтів. На основі ідеї про покращення коефіцієнтів стійкості до вищого рівня в методи аналізу стійкості введено силу опори в конструкції та силу анкера для анкерного болта в опорі з об‘єднаної методики «опора-анкер». Це дозволяє оцінити в застосованій методиці розмір секції в опорі і кількість анкерних болтів. Інженерні застосування запропонованої методики показали суттєву ефективність у тисячах випадків інженерного захисту.
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| first_indexed | 2025-12-07T16:36:00Z |
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2013 ПРИКЛАДНАЯ МЕХАНИКА Том 49, № 3
ISSN0032–8243. Прикл. механика, 2013, 49, № 3 135
H . K . C h e n , H . M . T a n g
STUDY ON THE SUPPORT - ANCHOR COMBINED TECHNIQUE
TO CONTROL PERILOUS ROCK AT THE SOURCE OF AVALANCHE
BY FRACTURE MECHANICS
Department of Geotechnical & Geological Engineering, Chongqing Jiaotong University,
Chongqing 400074, China; e-mail: chk99@163.com
Abstract. As a kind of existing and potential geological disaster at source of avalanche
on cliffs or steep slopes, perilous rock has developed in the western area of China widely
and it poses a serious threat to highways, railways, pipelines, cities, and mining for a long
time. More than ten years of engineering experience have shown the necessity and impor-
tance to pay our attention to the avalanche sources in active collapse mitigation. The support
- anchor combined technique is devoted to the active hazard mitigation measures of perilous
rock. This paper introduces fracture mechanics to investigate the design procedure of the
support - anchor combined technique. To obtain reasonable design parameters of the tech-
nique, both stability assessment criterion and three safety classes of protection engineering
for perilous rock is proposed, further, stable analysis methods for various types of perilous
rock are established by using fracture mechanics. Abiding by the idea that to improve stabil-
ity coefficient to a higher level, the support force of structure and the anchorage force of
anchorbolt from the support - anchor combined technique are introduced into stability
analysis methods established above, which can estimate the section dimension of support
subunit and the amount of anchorbolt of the technique. Engineering applications of the tech-
nique in thousands of protection engineering have identified the remarkable effectiveness.
Key words: perilous rock at source of avalanche, loads and loading combinations, frac-
ture stress intensity factor, stability coefficient of perilous rock, the support – anchor com-
bined technique, fracture mechanics.
1. Introduction.
Rockfall is defined as the falling of single rock or stone with volumes smaller than 5 m3,
while rock avalanche belongs to packet collapse (Chen, et al., 2001). In the past ten years,
hundreds million dollars in economic losses are produced and about 6000 persons are killed
by rockfall and avalanches in China. A large amount of rock avalanche with ~2×109 m3 in
volumes and deposits up to 200-300 m thick at Karivhoh, travelling more than 7 km and
covering about 18km2, all rock-avalanche bodies is composed of intensively crushed debris
and overlain by a blocky carapace (Strom, 2004). Rockfalls and rock avalanches belong to a
major erosion process shaping ridge crests and alpine summits (Cox and Allen, 2009).
Strong seismic shaking caused or triggered most of gigantic large-scale rock-slope failures
through reconnaissance in the Tien Shan (Strom and Korup, 2006). The effective friction
coefficient of rock avalanches diminishes gradually as a function of the avalanche volume
(Blasio, 2009). By considering the maximum obstacle height at the slope surface and the
radius of the falling rock, one formula to estimate tangential coefficient of restitution was
proposed by Dorren et al. (2006). The sensitivity of lateral dispersion of rockfall trajectories
on slope had been systematically evaluated as a function of macro-topographic, micro-
topographic and model special features by Crosta and Agliardi(2004). Based on variations in
kinetic and potential energies and frictional losses, Zambrano (2008) proposed one formula
to estimate movement velocities of large rock body. To determine factors for rockfall source
136
area, rockfall tracks and rockfall runout zones on a forested slope in mountainous terrain, a
combined approach using field and modeling techniques was put forward by Dorren et al.
(2004). The energy of avalanche dissipated not only through friction but also during impacts
and block breakage (Tommasi, et al., 2008). Manzella and Labiouse (2008) presented an
experimental study of rock avalanches runout and propagation carried out with a small-scale
physical model.
However, studies before-mentioned are focused on the subsequent processes after oc-
currence of paroxysmal avalanches. To achieve hazard mitigation effectively before the oc-
currence of paroxysmal avalanches, putting our attention on the avalanche sources has a
significant realistic meaning. With regards to this, Chen and Tang (2004) defined potential
unstable rock block at avalanche source on cliffs or steep slopes as perilous rock. Further,
attention is focused on the dominant fissure behind perilous rock, failure mechanism for all
kinds of perilous rock was investigated in detail by Chen et al. (2006, 2007, 2008) and Tang
et al. (2010). Stability analysis method for perilous rock is classified as sliding perilous rock,
toppling perilous rock and falling perilous rock, which is comprehensively established by
Chen et al. (2004, 2009). Due to existing extensively for toppling perilous rock, the support
- anchor combined technique, granted the patent of invention by the State Intellectual Prop-
erty Office of China (ZL200610054335.7), is applied widely in practice. To promote appli-
cation of the technique in engineering design procedure, this paper will make a comprehen-
sive description by using fracture mechanics.
2. Stability assessment criterion.
Stability of perilous rock at source of avalanche can be characterized by stability coeffi-
cient under action of loads. Unstable, primary stable and stable statuses are classified in sta-
bility analysis of perilous rock. Chen et al. (2004, 2009) proposed the stability assessment
criterion of perilous rock (Table 1). For example, to anyone of sliding perilous rock, it is
designated in unstable status, primary stable status and stable status if its stability coefficient
is less than 1,0, in 1,0 ~ 1,3, and bigger than 1,3, respectively.
It is persuasive to consider safety classes of protection engineering of perilous rock.
Hundreds of protection engineering, built in the area of the Three Gorges Reservoir of
China, have displayed the safety criterion of protection engineering of perilous rock showed
in table 2. Safety class A represents the objective of protection, such as important city, in-
dustrial and mining establishments, or transportation junction and public utilities, safety
class B represents the objective of protection, such as less important town, buildings, indus-
trial and mining establishments, or important artery traffic, and safety class C represents
anyone of objectives except safety class A and B. For example, to any one of toppling peril-
ous rock, whose stability coefficient after implementation of protection engineering must be
more than 1,5 to safety class A, 1,4 to safety class B, and 1,3 to safety class C.
Table 1. Stability assessment criterion of perilous rock.
Stable status Unstable Primary stable Stable
Sliding perilous rock ＜1,0 1,0~1,3 ＞1,3
Toppling perilous rock ＜1,0 1,0~1,5 ＞1,5
Falling perilous rock ＜1,0 1,0~1,5 ＞1,5
Table 2. Factor of safety of protection engineering of perilous rock
Safety class A B C
Sliding perilous rock 1,40 1,30 1,20
Toppling perilous rock 1,50 1,40 1,30
Falling perilous rock 1,60 1,50 1,40
137
3. Stability coefficient of perilous rock using fracture mechanics.
3.1 Loads and lading combinations acting on perilous rock. Loads and lading combi-
nations acting on perilous rock dominate the stability status of perilous rocks. Three kinds of
load acting on perilous rock, i.e., dead weight of perilous rock, water pressure in dominant
fissure (including statuses in nature and in rainstorm) and seismic force, are paid attention to
the stability analysis. Moreover, two types of seismic force, horizontal seismic force and
vertical seismic force, are respectively distinguished. For the three kindes of load, dead
weight of perilous rock belongs to permanent load, water pressure in dominant fissure be-
longs to periodic load varying with statuses in natural and in rainstorm, and seismic force
belongs to incidental load with low frequency.
Fig. 1. Loads acting on perilous rock.
Loads acting on perilous rock are showed in Fig. 1. Decomposing W, PL and PV along
the orientation and in the normal direction of dominant fissure, integrated tangent force and
normal force are calculated in formula (1) and (2), respectively.
sin)(cos VL PWPT ; (1)
cos)(sin VL PWPN ; (2)
VW ; (3)
WkP LL ; (4)
WkP VV , (5)
where, T represents the integrated tangent force (kN), N stands for the integrated normal
force (kN), PL and PV represent the horizon component and the vertical component of earth-
quake force acting on the center of gravity of perilous rock respectively (kN), β is the dip
angle of dominant fissure (Degree), W represents the dead weight of perilous rock (kN), V
represents the volume of perilous rock (m3), kL is designated as the coefficient of horizontal
seismic force, while kV is represented of vertical seismic force, γ is the specific gravity of
perilous rock every cubic meter (kN/m3).
When the end point O of dominant fissure is lower than the center point A of gravity in
perilous rock, flexural moment along point O obtains in formula (6).
aPbPWM LV )( . (6)
However, when point O is above point A, formula (6) is adjusted as formula (7).
138
aPbPWM LV )( . (7)
In formula (6) and (7), parameters a and b denote the vertical distance and the horizon
distance between point A and point O, respectively.
Moreover, assuming the distribution of water pressure in dominant fissure is linear
along the fissure, formulas to calculate water pressures in natural status and in rainstorm
status are established, showed in formula (8) and (9), respectively.
leQ 2
w18
1 ; (8)
leQ 2
w9
2 , (9)
where Q is the water pressure acting on perilous rock (kN), e is the vertical height of domi-
nant fissure (m), γw is the water gravity every cubic meter in dominant fissure (kN/m3), l
represents the horizontal length of perilous rock along the orientation of slope (m).
It should be noted that PL and PV can’t be considered simultaneously in all formulas
above and due to the impossibility to reach the same perilous rock for P-wave and S-wave
triggered by earthquake.
Based on appearance frequency of loads, three types of lading combination are recom-
mended, showed as followings.
Case 1: Dead weight of perilous rock and water pressure in nature status in dominant
fissure.
Case 2: Dead weight of perilous rock and water pressure in rainstorm status in domi-
nant fissure.
Case 3: Dead weight of perilous rock, water pressure in rainstorm status in dominant
fissure and seismic force.
Specially, case 1 is ignored in stability analysis of toppling perilous rock, and so does
case 2 in falling perilous rock. To a concrete perilous rock, the lading combination with the
minimum stability coefficient is designated as the design load of protection engineering.
3.2 Fracture stress intensity factor of dominant
fissure in perilous rock. In view of fracture mechan-
ics, destabilization process of perilous rock belongs to
a fracture problem of dominant fissure under action of
loads, representing in T, N, M and u (Fig. 2). Assum-
ing it is uniform distribution of T and N along domi-
nant fissure, the fracture model showed in Fig. 2 is
decomposed into 4 categories dominated by u, τ, M
and σ, respectively (Fig. 3), and described in detail as
followings.
To situation A in Fig. 3, introducing uniform dis-
tribution assumption of water pressure along dominant
fissure, the fracture stress intensity factor of the domi-
nant fissure can be determined in formula (10).
11 05,51K u a . (10)
Fig. 3. Decomposition of fracture model of dominant fissure.
Fig. 2. Fracture model of dominant
fissure.
139
To category B in Fig. 3, the fracture stress intensity factor under action of shear stressτ-
can be determined in formula (11).
2 01,12K a . (11)
To category C in Fig. 3, the fracture stress intensity factor under M action can be deter-
mined in formula (12).
0max13 )( aaFK . (12)
And to category D in Fig. 3, the fracture stress intensity factor under action of normal
stressσcan be calculated in formula (13).
14 01,12K a . (13)
Further, some indirect variables in formula (11), (12) and (13) are calculated in follow-
ing formulas.
sin0ae ; ww2
1
hu ;
H
T sin
;
2 3 4( ) 1,122 1,40 7,33 13,08 14,00F a R R R R ;
2max
6
H
M
;
H
e
R ;
H
N sin
.
Abiding by the superimposition assumption of the fracture stress intensity factor, for-
mula (14) is devoted to type I fracture stress intensity factor of dominant fissure in perilous
rock.
1413111 KKKK (14)
3.3 Fracture stability coefficient of perilous rock. To pay our attention to the dominant
fissure of perilous rock, both formula (15) and (16) are effective to estimate fracture angle θ0
and union fracture stress intensity factor Ke of rock near the end of dominant fissure, respec-
tively.
2
0 0
0
0
3 8
arccos
9
k k
k
; (15)
2 2
1 1 2 2 3 1 4 2 5 1 2
1
[ ]
2
K k K k K k K k K k K K e , (16)
where k0 = (K1/K2)
2, K1 represents the tension fracture stress intensity factor of dominant
fissure (kPa٠m1/2), K2 represents the shear fracture stress intensity factor of dominant fissure
(kPa٠m1/2), and some indirect variables such as k1 ~ k8 are calculated in the following
formulas
2 20 0 0
1 2 0 0 3 1 7
1
cos ; (3cos 1)sin 3sin cos ; ;
2 2 2 2
k k k k k
2 2 0 0
4 6 8 5 1 6 7 8 6 0 0
1
; 2( ); 3sin cos (3cos 1)sin ;
2 2 2
k k k k k k k k k
0 0
7 0 8 0sin cos ; (3cos 1)cos .
2 2
k k
Further, one formula to estimate fracture stability coefficient of perilous rock is pro-
posed in accordance with the ratio of the fracture toughness to the union fracture stress in-
tensity factor near the end of dominant fissure, showing as formula (17).
e
IC
s K
K
F . (17)
140
In formula (17), KⅠC is the rock fracture toughness near the end of dominant fissure
(kPa٠m1/2), determined by fracture mechanical testing in laboratory.
Comparing Fs identified by using formula (17) with the criterion of stability showing in
Table 1, the safety status of perilous rock is reasonably discriminated.
4. Calculation of the support force
and the anchor force in the support-
anchor combined technique.
Mechanical model of the support-
anchor combined technique is expressed in
Fig. 4. If the factor of safety of the protec-
tion engineering of perilous rock is repre-
sented in 0
sF designating in Table 2, it is
necessary to choose suitable techniques
such as the support-anchor combined tech-
nique when 0
ss FF . Further, a proportion
between support force and anchorage force
is introduced, then
ms NrN 0 , (18)
were, Ns represents the support force (kN),
Nm is the anchorage force (kN), and r0 is the
proportionality factor of support force to
anchorage force, usually sampled between 2
and 2,5.
Obviously, the next relational expression needs to follow in design of protection work.
0IC
f
e
s
K
F
K
, (19)
where, parameter f
eK represents the union fracture toughness of rock near the end of domi-
nant fissure after the implementation of protection engineering (kPa٠m1/2).
According to formula (19), the next expression exists.
f IC
e 0
s
K
K
F
. (20)
Letting fracture angle θ0 of rock near the end of dominant fissure in perilous rock is the
same as all about in the constructing of protection engineering, so indirect variables k1 ~ k5
are constant, and parameter f
eK depends on K1 and K2 unavoidably, expressed
as f
1K and f
2K respectively. Hereby, formula (16) is rewritten as followings.
][
2
1 f
2
f
15
2f
24
2f
13
f
22
f
11
f
e KKkKkKkKkKkK . (21)
To a concrete perilous rock, when the support-anchor combined technique is imple-
mented, support force Ns and anchorage force Nm are introduced, which produces the tan-
gent force Tf, the flexural moment Mf and the normal force Nf acting on the dominant fis-
sureare calculated in formula (22), (23) and (24), respectively.
sin)cos( sm
f NNTT ; (22)
)sin(cmcs
f aNbNMM ; (23)
Fig. 4. Mechanical model of the support -
anchor combined technique.
141
cos)sin( sm
f NNNN , (24)
where θ is the dip angle of anchorbolt (degree), ac designates the vertical distance between
the end of dominant fissure and the intersection point between anchorbolt and dominant
fissure (m), bc expresses the horizontal distance between the end of dominant fissure and the
support point (m), and the others are the same before.
Based on the formula (22), (23) and (24), we obtain σmax, σ and τ easily by considering
implement of the technique. Further, methods to solve corresponding fracture stress inten-
sity factor are established.
mcc02013
f
13 )]sin([
6
)( Nabr
H
aaFKK ; (25)
f
14 14 0 0 m2
6
1,12 [sin( ) cos )]K K a r N
H
. (26)
Then
f 0 c c
1 1 0 0 m2 2
6 ( ) 6 ( )
1,12sin( ) 1,12 cos sin( )
r b F a a F a
K K a r N
H H
; (27)
0f
2 2 0
1,12
[cos( ) sin ] m
a
K K r N
H
. (28)
To simplify the operation, letting
0 c c
1 0 0 2 2
6 ( ) 6 ( )
[1,12sin( ) 1,12 cos sin( )]
r b F a a F a
t a r
H H
;
0
2 0
1,12
[cos( ) sin ]
a
t r
H
,
so formula (27) and (28) express as m11
f
1 NtKK and m22
f
2 NtKK respectively, and
substituting them into formula (21), the next formula is derived.
f 2
e 1 2 m 3 m 4 m 5
1
2
K l l N l N l N l , (29)
where indirect variables are expressed as
22111 KkKkl ; 22112 tktkl ; 21
2
24
2
133 tttktkl ;
)(22 122152241134 tKtKktKktKkl ; 215
2
24
2
135 KKkKkKkl .
Combining formula (29) with formula (20), we obtain the formula to estimate the an-
chorage force Nm
2 2 2
4 2 4 2 3 2 52
3 2
1
2 ( 2 ) 4( )( )
2( )mN l Al l Al l l l A
l l
, (30)
where, 1
0
sIC /2 lFKA .
Substituting Nm into formula (18), then the support force Ns is determined.
To support subunit of the technique, when admissible compressive strength of support
subunit is represented in [Rc] the section dimensions of support subunit is effective to esti-
mate in formula (31)
b1 × b2 ≥
][ c
s
R
N
, (31)
where, b1 and b2 are the length and the width of the support (m), respectively.
Meanwhile, to anchorage subunit of the technique, when admissible tension strength
every anchorbolt is expressed in [T], anchorbolts n required in protection works can be esti-
mated in formula (32)
142
n ≥
][
m
T
LN
, (32)
where, L represents the length of perilous rock along the orientation of cliff or slope (m). All
these anchorbolts must be arranged to abide by the corresponding standard such as the stan-
dard DB50/5029-2004. However, anchorbolts, located at the lowest position on the perilous
rock, must be higher than (ac + Btanθ), and B is the average width of perilous rock (m).
5. Engineering application.
There are three cliffs with 150~180m in height on the southern slope of Mt. Taibaiyan
at Wanzhou city in area of the Three Gorges Reservoir of China. 61 perilous rocks with
2,5×105 m3 in volumes exists on the cliffs explored in recent years. Perilous rocks are com-
posing of quartzose arkose is about 25kN/m3 in bulk density in natural status, about 600kPa
in admissible tension strength, and 2700kPa in admissible shear strength. The fracture
toughness of the rock is about 2007 kPa٠m1/2. Horizontal seismic coefficient is 0,05, while
vertical seismic coefficient is 0,08 in the engineering region. Taking the perilous rock,
marked W12#, as an example, whose physical dimension is 32,7 m in length, 6,7 m in width
perpendicular to surface of the cliff, and 21,6 m in height, expression for the support-anchor
combined technique is presented in details. Continue section of dominant fissure in the per-
ilous rock is 20,4 m in length, 62,5°in dip angle. Anchorbolt required in the protection engi-
neering is designed with 32 cm in diameter and 30°in dip angle, bearing capacity every an-
chorbolt is about 180 kN. Support structure in the integrated technique is casted in-situ by
using C20 concrete. Admissible compressive strength of concrete isn’t less than 20MPa.
Factor of safety of the protection engineering is 1,5. Some parameters are proposed in the
design of the protection engineering considering geometric shape of the perilous rock,
bc=5,1 m, ac=7,5 m, and r0=2,4.
Calculation of the perilous rock is showed expressly in table 3. Further, engineering de-
sign is made based on the calculated results. Two aspects are pressed in the design showed
in Fig. 5(a), rectangle supports with section 0,45m×0,60m and constructed every 1m along
the direction of length of perilous rock, meanwhile, anchorbolts are installed by taking the
pattern of 1,0m×1,0m on the perilous rock. The protection engineering showing in Fig. 5(b)
is brought to success on May, 2005. Hitherto, the hazard mitigation effect is remarkable.
Table 3 Calculation results to the W12# perilous rock
0 /°
K1
/ kPa m
K2
/ kPa m
Ke/
kPa m
ICK
/ kPa m
Fs
Nm
/kN
Ns
/kN
b1×b2
/m2
Number
of an-
chorbolt
46,08 1809,11 1206,52 2132,86 2007 0,9410 2117,57 5082,17 ≥0,254 ≥ 385
Fig. 5. Design and construction for the W12# perilous rock, (a) shows the design section to
control the perilous rock, and (b) shows the concrete engineering in the design.
(b)
(a)
143
6. Conclusions. More than ten years of engineering experience have showed the neces-
sity and importancet to pay our attention to the avalanche source in active collapse mitiga-
tion. The support - anchor combined technique is devoted to the active hazard mitigation
measures of perilous rock, four conclusions are concluded as followings.
The first, stability assessment criterion of perilous rock is proposed for all kinds of per-
ilous rock at avalanche source, and three safety classes of protection works for perilous rock
disaster are identified. Further, loads acting on perilous rock are classified as dead weight of
perilous rock, water pressure in dominant fissure and seismic force. In accordance with the
frequency of all kinds of load, three lading combinations are clearly designated.
The second, methods to determine fracture stress intensity factor of dominant fissure in
perilous rock under action of loads are established by using fracture mechanics, and meth-
ods to solve the fracture stability coefficient of perilous rock is defined by the ratio of the
fracture toughness to the union fracture stress intensity factor of rock near the end of domi-
nant fissure.
The third, in connection with the support - anchor combined technique, the calculation
methods in engineering design are based on the stability coefficient of perilous rock by
drawing up the support force of support structure and the anchorage force of anchorbolt,
which can estimate the section dimension of support subunit and the amount of anchorbolts
against the perilous rock disaster.
The fourth, applications of the support - anchor combined technique in thousands of
protection works have displayed remarkable effectiveness of the technique in perilous rock
disaster mitigation.
Finally, it is worthy noting that rocks with serious weathering on the top of and under
the bottom of the support structure must be cleared in the design of technique, and some
expanding concrete about 20cm thickness space between the top of support structure and the
bottom of perilous rock must be applied and strong suggested.
Acknowledgments.
Ever since a long time ago, perilous rock and avalanche had become the most serious
geological disaster in western China. Studies are carried out by the scientific group and led
by the authors have been continuously making under grant of tens of fund, such as the Na-
tional Natural Fund of China “Study on rupture mechanism of perilous rock”(No.50678182)
more than ten years(have been making continuously under the grant of tens of fund more
than ten years, such as the National Natural Fund of China “Study on rupture mechanism of
perilous rock”(No.50678182)). Great assistance and encourage have been given by scien-
tists, such as professor Li Jijun, academician of the Chinese Academy of Science (CAS),
professor Xian Xuefu, professor Zheng Yingren, and professor Zhou Fengjun, academicians
of the Chinese Academy of Engineering (CAE ). Sincere thanks are liberated by the authors
to these scientists and fund departments in charge.
Р Е ЗЮМ Е . Більш ніж десять років інженерного досвіду в західній частині Китаю показали
необхідність і важливість уваги до джерел лавин з метою активного зменшення катастроф. Для вимі-
рювання активного зменшення ризику від небезпечних грунтів розроблена об‘єднана методика «опо-
ра-анкер». У роботі застосована механіка руйнування для дослідження процедури створення розра-
хункової схеми об‘єднаної методики «опора-анкер». Для отримання коректних параметрів схеми
запропоновано критерій оцінки стійкості і три класи безпеки інженерного захисту для небезпечних
грунтів. Далі на основі механіки руйнування розвинуті стійкі методи аналізу для різних типів небез-
печних грунтів. На основі ідеї про покращення коефіцієнтів стійкості до вищого рівня в методи ана-
лізу стійкості введено силу опори в конструкції та силу анкера для анкерного болта в опорі з
об‘єднаної методики «опора-анкер». Це дозволяє оцінити в застосованій методиці розмір секції в
опорі і кількість анкерних болтів. Інженерні застосування запропонованої методики показали суттєву
ефективність у тисячах випадків інженерного захисту.
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From the Editorial Board: The article corresponds completely to submitted manuscript.
Поступила 12.10.2010 Утверждена в печать 22.11.2012
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| id | nasplib_isofts_kiev_ua-123456789-87768 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 0032-8243 |
| language | English |
| last_indexed | 2025-12-07T16:36:00Z |
| publishDate | 2013 |
| publisher | Інститут механіки ім. С.П. Тимошенка НАН України |
| record_format | dspace |
| spelling | Chen, H.K. Tang, H.M. 2015-10-24T19:50:47Z 2015-10-24T19:50:47Z 2013 Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics / H.K. Chen, H.M. Tang // Прикладная механика. — 2013. — Т. 49, № 3. — С. 135-144. — Бібліогр.: 16 назв. — рос. 0032-8243 https://nasplib.isofts.kiev.ua/handle/123456789/87768 As a kind of existing and potential geological disaster at source of avalanche on cliffs or steep slopes, perilous rock has developed in the western area of China widely and it poses a serious threat to highways, railways, pipelines, cities, and mining for a long time. More than ten years of engineering experience have shown the necessity and importance to pay our attention to the avalanche sources in active collapse mitigation. The support - anchor combined technique is devoted to the active hazard mitigation measures of perilous rock. This paper introduces fracture mechanics to investigate the design procedure of the support - anchor combined technique. To obtain reasonable design parameters of the technique, both stability assessment criterion and three safety classes of protection engineering for perilous rock is proposed, further, stable analysis methods for various types of perilous rock are established by using fracture mechanics. Abiding by the idea that to improve stability coefficient to a higher level, the support force of structure and the anchorage force of anchorbolt from the support - anchor combined technique are introduced into stability analysis methods established above, which can estimate the section dimension of support subunit and the amount of anchorbolt of the technique. Engineering applications of the technique in thousands of protection engineering have identified the remarkable effectiveness. Більш ніж десять років інженерного досвіду в західній частині Китаю показали необхідність і важливість уваги до джерел лавин з метою активного зменшення катастроф. Для вимірювання активного зменшення ризику від небезпечних грунтів розроблена об‘єднана методика «опора-анкер». У роботі застосована механіка руйнування для дослідження процедури створення розрахункової схеми об‘єднаної методики «опора-анкер». Для отримання коректних параметрів схеми запропоновано критерій оцінки стійкості і три класи безпеки інженерного захисту для небезпечних грунтів. Далі на основі механіки руйнування розвинуті стійкі методи аналізу для різних типів небезпечних грунтів. На основі ідеї про покращення коефіцієнтів стійкості до вищого рівня в методи аналізу стійкості введено силу опори в конструкції та силу анкера для анкерного болта в опорі з об‘єднаної методики «опора-анкер». Це дозволяє оцінити в застосованій методиці розмір секції в опорі і кількість анкерних болтів. Інженерні застосування запропонованої методики показали суттєву ефективність у тисячах випадків інженерного захисту. Ever since a long time ago, perilous rock and avalanche had become the most serious geological disaster in western China. Studies are carried out by the scientific group and led by the authors have been continuously making under grant of tens of fund, such as the National Natural Fund of China “Study on rupture mechanism of perilous rock”(No.50678182) more than ten years(have been making continuously under the grant of tens of fund more than ten years, such as the National Natural Fund of China “Study on rupture mechanism of perilous rock”(No.50678182)). Great assistance and encourage have been given by scientists, such as professor Li Jijun, academician of the Chinese Academy of Science (CAS), professor Xian Xuefu, professor Zheng Yingren, and professor Zhou Fengjun, academicians of the Chinese Academy of Engineering (CAE ). Sincere thanks are liberated by the authors to these scientists and fund departments in charge. en Інститут механіки ім. С.П. Тимошенка НАН України Прикладная механика Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics Анализ в рамках механики разрушения с помощью комбинированной методики "опора-анкер" с целью управления опасным грунтом как источника обвала Article published earlier |
| spellingShingle | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics Chen, H.K. Tang, H.M. |
| title | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics |
| title_alt | Анализ в рамках механики разрушения с помощью комбинированной методики "опора-анкер" с целью управления опасным грунтом как источника обвала |
| title_full | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics |
| title_fullStr | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics |
| title_full_unstemmed | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics |
| title_short | Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics |
| title_sort | study on the support-anchor combined technique to control perilous rock at the source of avalanche by fracture mechanics |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/87768 |
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