Research Article Model Test of Anchoring Effect on Zonal...

Hindawi Publishing CorporationThe Scientific World JournalVolume 2013 Article ID 935148 16 pageshttpdxdoiorg1011552013935148

Research ArticleModel Test of Anchoring Effect on Zonal Disintegration inDeep Surrounding Rock Masses

Xu-Guang Chen123 Qiang-Yong Zhang3 Yuan Wang1 De-Jun Liu3 and Ning Zhang3

1 Institute of Tunnel and Urban Railway Engineering Hohai University Nanjing 210098 Key Laboratory of Ministry of Education forGeomechanics and Embankment Engineering Hohai Univ Nanjing 210098 China

2 State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining amp TechnologyXuzhou 221000 China

3 Research Center of Geotechnical and Structural Engineering Shandong University Jinan 250061 China

Correspondence should be addressed to Xu-Guang Chen chenxuguang1984yahoocn

Received 14 May 2013 Accepted 16 June 2013

Academic Editors A Arulrajah M W Bo and J Chu

Copyright copy 2013 Xu-Guang Chen et alThis is an open access article distributed under theCreativeCommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The deep rock masses show a different mechanical behavior compared with the shallow rock masses They are classified intoalternating fractured and intact zones during the excavation which is known as zonal disintegration Such phenomenon is agreat disaster and will induce the different excavation and anchoring methodology In this study a 3D geomechanics model testwas conducted to research the anchoring effect of zonal disintegration The model was constructed with anchoring in a half andnonanchoring in the other half to compare with each other The optical extensometer and optical sensor were adopted to measurethe displacement and strain changing law in the model test The displacement laws of the deep surrounding rocks were obtainedand found to be nonmonotonic versus the distance to the periphery Zonal disintegration occurs in the area without anchoringand did not occur in the model under anchoring condition By contrasting the phenomenon the anchor effect of restraining zonaldisintegrationwas revealedAnd the formation condition of zonal disintegrationwas decided In the procedure of tunnel excavationthe anchor strain was found to be alternation in tension and compression It indicates that anchor will show the nonmonotonic lawduring suppressing the zonal disintegration

1 Introduction

Shallow-buried resources have been decreasing with therapid progress in global economy Thus the exploitation ofdeeply buried resources has drawn interest from a numberof countries South Africa Russia India and China haverecently conducted a series of exploitations of deep mineswith embedded depths of more than 1000m In China theJinchuan nickel mine Tongling copper mine and Dingji coalmine are more than 1000m deep whereas the Jinping IIHydropower Station is 2600m deep The Kolar gold mine inIndia is 2400m deep and the deepest gold mine worldwideresiding in South Africa is 3700m deep This series ofnewphenomena in underground engineeringwith increasingembedded depth has caused the emergence of a failurephenomenon called zonal disintegration Shemyakin et al[1] defined zonal disintegration as the alternated regions of

fractured and relatively intact rock masses appearing aroundor in front of the working slope during the excavation oftunnels in the deep rock mass This phenomenon has notbeen observed in shallow rock engineering Moreover zonaldisintegration presents a serious hazard to the stability ofsurrounding rocks (Qian) [2]

Zonal disintegration in many deep tunnels has beenmonitored using the physical probe method Adams andJager [3] were the first to observe such phenomenon byusing a bore periscope at an embedded depth of 2000m to3000m in the Witwatersrand gold mine in South AfricaHe reported that zonal disintegration occurred when thetunnel was excavated either by drilling and blasting or themechanized method However explosion was eliminated asthe result of zonal disintegration after Shemyakin [1 4ndash6]explored zonal disintegration in Taimyrskii deep mine inRussia by using a resistivity meter

2 The Scientific World Journal

Zonal disintegration phenomenon differs from the engi-neering response in shallow rock excavation and as such can-not be explained perfectly under the framework of traditionalrock theory In accordance with the concepts of traditionalcontinuum mechanics the enclosing rock mass around adeep tunnel is divided into fractured plastic and elasticregions from the periphery of the tunnel to infinity Zonaldisintegration a characteristic of deep rock masses has beenthe focus of recent investigations

A number of experts have used various methods toexplain zonal disintegration Sellers and Klerck [7] indicatedthat the discontinued surface could be one of the derivationsof zonal disintegrationMalan and Spottiswoode [8] analyzedthe relationship between the shock bump and the zonaldisintegration of a top plate in the surrounding rocks ofa mining field Zhou et al [9] investigated the dynamicexcavation of a deep tunnel to determine the residual strengthand the forming time of fractured zones Gu et al [10] con-ducted a compression test on cylinder specimen and regardedaxial stress as an important factor for zonal disintegrationOther studies on zonal disintegration have applied differenttechniques such as a series of compression tests Pan [1112] nonequilibrium thermodynamics (Metlov et al) [13]Hamiltonian time-domain variation (Li et al) [14] and thenon-Euclideanmodel (Guzev and Paroshin) [15] In additionsome elastic-plastic theories have been adopted to analyzethe forming mechanism of zonal disintegration (Wang et al[16 17] He et al [18] Zhou et al [19ndash24] Reva and Tropp[25] Tan et al [26] Wu et al [27] Odintsev [28]) A zonaldisintegration phenomenon is shown in Figure 1

Zonal disintegration is a unique failure phenomenonposing a large-scale disaster during excavation of deep rockmasses (Laptev and Potekhin) [29] It threatens the stability ofdeep tunnel and will cause large collapse of rock mass whichinduces a great loss It is of great importance to know theanchoring effect on zonal disintegration and the mechanicalbehavior under anchoring condition in deep rock massesfor the stability of deep tunnel To the authorsrsquo knowledgeanchoring effect on zonal disintegration phenomenon indeep rock masses is not investigated previously

In this paper the Huainan coal mine in which zonaldisintegration occurs in China was taken as the engineeringbackground The model tests on zonal disintegration werecarried on in the condition of anchoring and without anchor-ing in separate The model was built using an independentlydeveloped barites-iron-sand cementation analogical (BISA)material Through the analogical model test the damagepattern with and without anchoring was observed Thenonlinear deformation changing laws were clarified by usinga precise optical apparatus Based on this the anchoring effectand forming condition of zonal disintegration in deep rockmasses is revealed

2 Similarity Theory and Analogical Material

The geomechanical model test is an important scientific re-search method Similar to prototype engineering the modelwas designed based on the similarity principle An optical

Stands for fractured zoneStands for intact zone

Figure 1 Sketch of the zonal disintegration phenomena in deeptunnel

measuring apparatus was used in the geomechanical modeltestThe stress and displacement changing rules of the modeland strain of the anchor were monitored to determine thedeformation laws of prototype engineering The model testexhibits an advantage in studying the failure mechanism ofunderground cavities over in situ observation which relieson auditory-visual perception and is time-consuming

The geomechanical model test is an effective reducedscale method used for investigating special engineeringproblems based on the similarity principle The changinglaws of stress strain and displacement can be monitored bydesigning the model similar to that of prototype engineeringFollowing the similarity principle the data observed from themodel test can be used to reveal the stress distribution lawsand themechanism in prototype engineering thereby solvingactual problems

21 SimilarityTheory Thegeomechanicalmodel test requiresa suitable similar material that can reflect the mechanicalbehavior of a rock type The similar material and its proto-type must comply with the similarity principle The theoryrequires several similarity coefficients defined as ratios ofprototype parameters to model parameters to be constant(Fumagalli) [28 30]

119862120590= 119862120574119862119871 (1a)

119862120575= 119862120576119862119871 (1b)

119862120590= 119862120576119862119864 (1c)

119862120576= 1 119862

119891= 1

119862120601= 1 119862

120583= 1

(1d)

The Scientific World Journal 3

Table 1 Physical-mechanical parameters of the prototype rock and model material

Material type Volume weightKNsdotmminus3 EdefMPa CohesionMPa 120593 UCSMPa TSMPa NUXYPrototype 262 12970 10 43 8855 1401 0268Model 262 5188 04 43 354 056 0268

where 119862120590 119862120576 119862119864 119862119871 119862120574 119862119891 119862120601 and 119862

120583indicate the simi-

larity ratios of stress strain MOE geometry volume weightCOF internal friction angle and passion ratio respectively

The analogicalmaterial should have the properties of highvolume-weight low deformation module and changeableinner friction angle No crude material can fulfill all thesedemands and thus the similar material should be assembledartificially According to the similarity theory themechanicalparameters of the model can be readily obtained through theprototype

22 Proportion of the Similar Material There are severalInstitutes researching on the similar material such as ISMES(Institute of Experimental Models and Structures) in ItalyLNEC (National Laboratory for Civil Engineering) in Por-tugal and Tsinghua University in China [30 31] Their workshows that whether the model test can reflect the prototypeengineeringrsquos mechanical response depends on the chosenmaterialsThe suitable material should reflect the mechanicalbehavior of prototype engineering The proportion of eachcomponent is important for model simulation

The barite powder iron powder and quartz sand areselected to form the aggregate whereas the alcoholic solu-tion of rosin is used as the mucilage glue (Figure 2) Theproportion of the aggregates and the concentration of thealcohol solution of rosin decide the mechanical behaviorof the BISA material The barite-iron-sand (BISA) materialwas developed through hundreds of groups of proportioningtestsThe specimens of similar material were built by pouringthe material into a mould and compressing it (Figure 3)The material exhibits the following advantages stability inperformance widely variable mechanical parameters lowprice high volume-weight easy processing and no toxicityor side effects The BISA material which can be used formodeling a tunnel or underground powerhouse has obtaineda patent in China The material can be used to simulate allkinds of rocks including hard and soft rocksThe proportionof the material composition for surrounding rocks in theDingji coalminewas determined via the physical-mechanicalparameters test on the analogical material The mechanicalparameters of the material were tested in the proportion ofeach component in the material (Figure 3)

The laws between the mechanical parameters of materialand components proportion were derived by mechanicaltesting on hundreds of specimens

The medium sandstone in the bed stratum from theDingji coal mine and theHuainanmining area was processedinto a specimen The physical-mechanical parameters ofequivalent anchors were tested The mechanical parame-ters of the medium sandstone consist of the followingunconstrained compressive strength (UCS) of 8855MPatensile strength of 1401Mpa and deformation modulus of

Table 2 Proportion of the analogical material

I B S Portion ofthe gypsum

Concentration ofthe solution

Portion ofthe solution

1 11 042 25 75 50

Table 3 Physical-mechanical parameters of prototype and equiva-lent anchor

Anchor EdefGPa TSMPa Yield strengthMPa lengthcmPrototype 210 510 345 220Model 42 102 690 44

elasticity (Edef) of 1297GPa The similarity ratio of volumeweight for the analogical material is set to 1 1 whereas thesimilarity ratio of geostress is set to 1 50 Thus accordingto the similarity principle the mechanical parameters of theprototype and similar material are as follows (Table 1)

According to the curves between the mechanical param-eters and the material proportion the proportion of eachcomponent for medium sandstone is as follows (Table 2)

23 Equivalent Anchors The parameters of anchor adoptedin engineering are 12060120800times 800mm 119871= 22m Accordingto the similar principle the parameters of model anchor canbe got from the prototype anchor (Table 3)

After the mechanical test on the serious metal materials(Figure 4) the aluminum wire is selected as the equivalentanchor

3 Development of the Model Test System

31 Development of the Triaxial Model Test System In orderto simulate the 3 D geostress state of tunnel precisely the highgeostress-triaxial loading model test system was developedindependently Figure 5 is the design sketch and the photoof the system

The model test system is comprised of the high geostressloading system the computerized numerical control (CNC)hydraulic system and the support reaction apparatus Thehigh geostress loading system consists of jacks and loadingplatens which are used to apply high geostress It is set insidethe support reaction apparatus One end of the jacks wasdisposed with loading platen while the other was fixed to thesupport reaction apparatus with bolts There are 6 platens inall and one contacts each surface of the model which canapply loading at 3 directionsThe dimension of each platen is06 times 06 times 004m which is equal to the size of model surfaceThere arrange 4 hydraulic jets on each platen and the capacityof each jack is 40 tons The loading capacity of each platen is1600KNThehigh geostress loading system is connectedwith


Iron powder Cement

AlcoholRosinSolution

Barites powder

Figure 2 Proportion of the analogical material The barites powder iron powder and quarts sand are mixed together to make the aggregatethe solution of rosin and alcohol make the glue

(b)

(e)

(a)

(d)

(c)

(f)

Figure 3 Mechanical test on analogical material (a) is the specimen mould (b) is the specimens for UCS (c) is the specimens for directshear test (d) is the Brazilian test (e) is the uniaxial test (f) is the direct shear test


Strain gauge

(a) (b)

Figure 4 Mechanical test on equivalent anchor

2

34

1

5

6

(a)

2

34

1

5

(b)

Figure 5 Sketch and photos of the true 3D model test system The model was set inside the frame and the platen was set into the frameat 05 cm depth Then each direction of the model has the reserved displacement of 9 cm Notes (1) junction plate (2) hydraulic jacks (3)loading platen (4) oriented frame and (5) combination reaction frame for loading (6) excavation guiding platen

the CNChydraulic systemTheCNChydraulic system is usedto regulate and control loading value The support reactionapparatus is composed of box cast steel components whichcan be assembled flexibly It is solid enough to undertakesupport reaction to 5000KN high

During the triaxial compression on 3D model twoadjacent loading platens will interrupt each other because ofthe volume contraction So an oriented frame was developedto solve the problem The frame consists of 12 steel poleswhich are connected with each other Each pole was 5 cmthick and 70 cm long The model was set inside the frameand the platen was set into the frame at 05 cm depth Theneach direction of the model has the reserved displacement of9 cm A circle platen whose size is similar to the tunnel wasfixed into the two platens in front and back of themodel Andthe platens will be fixed during the loading on the model andtaken off when excavation of the tunnel (Figure 5) So theexcavation in 3D model can be solved

The advantages of the system are shown as follows(1) High geostress can be applied to the model in all 3

directions independently and synchronously And thegeostress can be remained stable for long term

(2) The problem of two adjacent loading platens thatinterrupted each other which was caused by thetriaxial compression was solved And the excavationin 3D model was realized

(3) The loading capacity is large enough to 2000KNwhich can simulate the cavern deep to 5000m Andthe loading precision reaches up to 05

32 Development of the High Precision Optical MeasuringSystem A micrometer is necessary because the multi-pointdisplacement meters are too huge for the model Thusa micrograting ruler multipoint displacement measuringSystem (GRDS) was developed to monitor the displacement


in the rock mass of the model (Figure 6) The Moire fringeis used to enlarge the displacement in the model The GRDSis composed of rack grating rulers steel wires balanceweight fixed end signal translating system (STS) and dataacquisition system (DAS) Several fixed ends were buried atthe measuring spots inside the model The fixed ends wereconnected to the grating ruler outside the model with thesteel wireThe steel wire was made up of special sterepsinemawithout any axial deformation and thus it is very flexibleand can be bent arbitrarily The steel wire was wrapped withTeflon pipe to eliminate friction between the steel wire andthe model The GRDS transformed the displacement of themodel to the grating ruler through the mechanical methodThen the real displacement was transferred to the opticalsignal by using an optical ruler The STS was connected tothe grating ruler with the guide line and the optical signalwas transformed to digital signal and then transferred to theDAS The displacement data of the model was displayed andstored instantaneously The high precision (1120583m) GRDS canbe used tomeasure the displacement in any direction as it canbe bent at any angle

The fiber bragg grating (FBG) was stuck to the analogicalmaterial blocks to make the grating strain sensor And it canbe used to measure the strain in each direction inside themodel (Figure 7)

The FBG can measure the strain changing outsidethrough the centre wavelength mobile The relationshipbetween the centre wavelength 120582

119861and the effective refraction

index 119899eff of grating and the period of grating Λ is

120582119861= 2119899effΛ (2)

where 120582119861is centre wavelength of the Bragg grating Λ is the

period of grating 119899eff is the effective refraction indexWhen the fiber is stretched Λ and 119899eff will change and

then the centre wavelength 120582119861will drift The wavelength

gets larger when the fiber is stretched while it gets smallerwhen the fiber is compressed The linear relationship will besatisfied

Δ120582119861= 120582119861(1 minus 119875

119890) 120576 = 119870

119890120576 (3)

where Δ120582119861is the variation of wavelength 119875

119890is the effective

optical coefficient (022 generally) 120576 is the axial strain offiber119870

119890is the sensitivity of strain measuring

When the grating generates strain in the stress conditionthe pitch of the grating will change to ΔΛ which will makethe wavelength change to Δ120582 so the strain can be got

120576 =Δ119897

119897=Δ120582

120582 (4)

4 Construction of the Model

To study the anchoring effect on zonal disintegration amodelwas built and divided to two halves to make compassion onehalf is anchored and the other half is nonanchoring

41 Simulation Range of the Model Themodel size is limitedby the reasonable size of the steel frame Within the frameif the similarity constant for the geometry 119862

119871is smaller than

1 50 then themodel tunnel will be too small to be excavatedIf the 119862

119871is very large then the relevant monitoring devices

will be too difficult to install and the monitoring data will beinaccurate Considering these prior factors 100 is taken as theoptimal similarity coefficient 119862

119871

The simulation range of the prototype is 30m times 30mtimes 30m According to the geometry similar scale 150 thedimension of the model is determined to 06m times 06m times06m and the model tunnel is 100mm times 776mm

42 Flow of Model Construction The model was madedelaminating Each layer is 10 cm high so 7 times are neededin all to finish the entire model The measuring componentswere set up when the material reached the designed height(see Figure 8)

43 Burying of the Measuring Components The measuringcomponents were disposed in the model including theoptical multipoint displacement meter and the grating Braggoptical strain sensor which were used to monitor the dis-placement and strain changing in the surrounding rocksrespectively Figures 9-10 show the section sketch and buryingprocedure of the measuring components in separate

44 Distribution and Burying of the Anchor The anchoredarea was applied with anchors while the other half was notBecause the anchor surrounding the tunnel is too intensivean equivalent principle of pulling resistance is adopted todispose the anchor A thick anchor is replaced by 4 thinanchors Considering of the quincuncial disposal of anchorit is not equal between the two adjacent sections There are 8anchors in section A and 7 anchors in section B in separateThe two sections are arranged alternately (Figure 11) Thegrouting material is mixed by the high thickness alcoholsolution of rosin whose stickiness and fluidity are both wellto meet the grouting demand

(1) Arrangement of anchors Figure 11 is the layoutsketch of the equivalent anchor As the figure showsthe equivalent anchor is arranged according to thequincunx There are 8 anchors in section A and 7anchors in section B The inter-row spacings are both16mThe two sections are arranged alternately alongthe axial direction of tunnel

(2) Burying of the anchors The embedded method andgrouting burying method are adopted together Theembedded method is adopted for the anchor of themiddle of model The grouting burying method isadopted for the entrance of the the tunnel

Figure 12 is the burying procedure of the embeddedanchor where (a) is for the side wall and (b) is for the arccrown After burying the material is backfilled and tampedtill the completion of the entire model


34

2

1

(a) The disassembled part

1

4

3

(b) The assembled device

1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7

(d) The optical ruler

Figure 6 Grating ruler multipoints displacement measuring system (GRDS) (1) Fixed end (2) guding frame (3) soft pipe (4) flexible steelwire (5) displacement transfer roller (6) balance weight (7) optical ruler (8) STS (9) DAS (10) cable

Figure 7 Grating strain sensor measuring system


(a) Charge mixture (b) Compaction (c) One layer finished

Figure 8 Procedure of the model building

TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm

Notes section I-I is for displacement measuring and section II-II

IIIII I

Figure 9 Layout sketch of monitoring sections in the model Themodel is divided to two parts anchored area and the area withoutanchoring The measuring sections were set to 3 which divides themodel to 4 parts evenly The II measuring section was chosen to bethe middle part of the model while the I and III sections are quarterand three-quarters of themodelThen themeasuring section can beused to monitor the deformation inside the model

The anchor burying of two sections near the cavern wascarried during the procedure of tunnel excavationThedetailsare shown in Figures 14(b)ndash14(d)

45 Tunnel Excavation and Model Testing The deep tunnelis in the 3D geostress state In order to simulate the geostressfields accurately the model was loading in true 3D state (Fig-ure 13) During the excavation the displacement and strainchanging laws were monitored and recorded (Figure 13)

The self-weight stress is 120574ℎ The loading which is perpen-dicular to the tunnel axial is 15120574ℎ (coefficient of horizontal

Table 4 The loading value of the model

Loadingdirection

Self-weightstress

Perpendicular tothe axial

Parallel tothe axial

LoadingvalueMpa 05 075 075

Loadingdirection

Self-weightstress

Perpendicularto the axial

Parallel to theaxial

pressure is 15)Where 120574 is the volumeweight ℎ is the embed-ded depth of the tunnelThe loading value is listed in Table 4

The excavation procedure of the model is shown asfollows (Figure 14)

5 Results of Model Test and Discussion

51 Displacement from the Grating Extensometer Figure 15shows the drawing sketch of grating extensometer Thedisplacement of surrounding rocks is labeled and connectedusing the smooth curve after excavation Then the changinglaws of displacement can be got The displacement changingsketch is placed together to compare It is known from thesketch of displacement surrounding the tunnel

(1) The displacement shows a very different changinglaw between the anchored model and nonanchoringmodel In the anchored model the displacementdecreases monotonously as the distance to the tunnelwall increases It is similar to the shallow embed-ded tunnel While in the nonanchoring model thedisplacement presents the undulate changing statuswherein the wave crest and the trough are arrangedalternately It completely differs from the shallowembedded tunnel

(2) Compared with the dissembled model the area oflarger displacement is the severely damaged regionIn the anchored model the displacements of no 1spot near the periphery are larger than the otherarea It indicates that this area is the damage zonein the traditional perception This is in accordancewith the phenomenon of periphery damage seriously


(a) Burying of optical Bragg fiber strain sensor

(b) Burying of GRDS

Figure 10 Burying procedure of the optical measurement sensor The sensor is Fiber Optical Bragg grating sensor where the precision is10minus3 120583120576 The spacing between those sensors is 1 cm

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

Stands for equivalent anchor 16 16mm times

Stands for rock type anchor 08 08mm times

(a) Distribution sketch along the axial direction

Section A (8 anchors) Section B (7 anchors)

(b) Section sketch

Figure 11 Layout sketch of the equivalent anchor

during the excavationThe displacement in arc crownis larger than the side walls This is correspondingto the phenomenon of serious damage and collapsein arc crown In the model without anchoring thewave crest region with a larger displacement is thefractured zone whereas the trough region with asmaller displacement is the intact zone The addi-tional displacement in the wave crest area which iscaused by the circular fracture increases the totaldisplacement

52 Strains from FBG Strain Sensor The strain results showthat both the radial and tangential strains were negative

before the excavation This indicates that the surroundingrocks were in compressive state When it is excavated tothe strain monitoring section the radial strain 120576

119903turns to

positive which indicates that the tensile strain appear in theradial directionThephenomenonwas in accordancewith theelastic-plastic strain field analysis of the ideal circular tunnel

Figure 16 is the diagram sketch of FBG strain sensor Theradial strain is labeled in the surrounding rocks nearby thetunnel after the tunnel excavation and measurement

As is shown in Figure 16 the radial strain in the surround-ing rocks both in the anchored model and nonanchoringmodel shows the same changing law it presents the fluctuatedistribution with the distance increasing from the periphery


(a) Anchor in the side walls

(b) Anchor in the arc crown

Figure 12 Burying procedure of analogical anchor

The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)

Figure 13 Loading state and test procedure of the model

The wave crest and the trough distribute alternately This lawis totally different from that in the shallow embedded tunnelThe phenomenon indicates that under the high geostressloading the radial tensile strain is the highest in a certainarea of the surrounding rocksThis area is almost circular andconcentrated in the tunnel and identified as the elastoplasticzone of the surrounding rock

Zonal disintegration phenomenon does not occur in theside walls and arc crowns of anchored model It is becausethe reinforcement effect improves the capacity of fracture-resistance of surrounding rocksThere is no reinforcing effect

in the nonanchoring area such as the invert of anchoredhalf model and the half model without anchoring Zonaldisintegration phenomenon occurs in these areas

53 Anchor Strain in the Middle Section of the Model Fig-ure 17 is the changing laws of anchor strain in the middlesection of the model measured by the strain gages

(1) The anchor strain is minus at the beginning oftunnel excavation It indicates that the anchors are incompressive state in high loading condition It turns


(a) Excavation (b) Applying anchor

(c) Grouting

Anchor

(d) Anchor finished

(e) Next excavation step (f) Breakthrough

Figure 14 Excavation procedure of model tunnels

to positive at the excavation of step 6 which is nearthe middle of the model (there are 14 excavation stepsin all) It indicates that anchors turn into tensile stateand work

(2) Most anchors (except nos 1 6 and 11) turn tomaximum state at excavation of 7 or 8This is becausethe anchor works at the largest effect when excavatedin the middle of the model which is the section ofanchor strain measurement

(3) A mount of anchors (nos 1 4 5 8 10 13 and14) shows the phenomenon of positive and negativealternation during the excavation process It indicatesthe tension and compression alternating of anchor

which is first observed in the geomechnical modeltest

Fang [32] used to observe the similar special phe-nomenon of tension and compression alternating in the deeptunnel of Jinchuan nickel mine 1150m deep He believesthat it is the self-organized phenomenon and the inherentcharacteristic of deep tunnel

54 Fracture Shape inside the Model Figure 18 is the photosof dissembled model which show the damage pattern

The zonal disintegration phenomenon of alternating frac-tured zone and intact zone occurs in nonanchoring modelThere are 4 fractured zones and 4 intact zones arranging in


Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01

23456 654321Right side wallLeft side wall

0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel

(b) Data of anchored model

654321

0051152

123456 6543210051152

115

0

654321

0051152Invert

Right side wallLeft side wall

Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel

(c) Data of model without anchoring

Figure 15 Displacement surrounding the model tunnel

space which are in accordance with the fractured shape of thein-situ observation in DINGJI coal mineThere are 2 obviousfracture lines in the bottom of the anchored model Zonaldisintegration also occurs in the invert of themodel But thereis not any fracture line occurs in the arc crown and side wallsthat is zonal disintegration phenomenon did not occur in theanchored part of model

After comparing with the model of anchored and nonan-choring it indicates that the anchoring effect reinforces theanchoring area of model to be a unity This impact makeszonal disintegration difficult to occur

55 Analysis of the Anchoring Effect on Zonal DisintegrationUnder high geostress conditions the surrounding rocks nearthe cavern wall yield to plasticity The principal stress field in

the plastic and the elastic zones is as follows (Figure 19) As isshown the tangential stress is the maximum principal stressAt the location of 119903 = 119877

119901 the tangential stress is the summit

valueAccording to Griffithrsquos criterion a fracture occurs when

the UCS of rocks under pressure reaches the threshold valueFairhurst and Cook (1966) [33] indicated that microcrackswould initiate and extend in the direction of the maximumprincipal stress when compressive stress reaches Griffithrsquosstrength 120590

119904 This finding explains the longitudinal splitting

of the rock specimen and the slabbing of the surroundingrocks in the rectangular openings which also holds truefor the circular cavern Given a unit rock in the systemof the polar coordinates (Figure 19) the second circularfracture extends towards the direction of the maximum


Tunnel

(a) Layout sketch of optical fiber strain sensor

654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel

(b) Strain of anchored model

654321

05001000

123456 654321Measuring points

0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel

(c) Strain of model without anchoring

Figure 16 Radial strain around tunnel measured by optical fiber strain sensor

principal stress (ie the tangential direction) when stressfulfills its relationship with the mechanical parameters of thesurrounding rocks The fracture is expected to transfix andform the circular fracture (ie the first fracture of the zonaldisintegration)when compressive loading is sufficiently largeFracture formation causes geostress redistribution in thesurrounding rocks inducing the formation of other ultimateequilibriumplastic zonesThe second circular fracture occurswhen the summit tangential stress is sufficiently large Zonaldisintegration occurs during the process cycle (Figure 19)

In the condition of high axial geostress the surroundingrock mass has the trend of zonal disintegrationWhen modelis anchored it is reinforced and the threshold value of fractureis enlarged So at the same geostress the zonal disintegrationdid not occur The model test indicates the trend of zonaldisintegration phenomenon existing under a condition of

high axial geostress And the reinforcement of anchor sup-presses the zonal disintegration in the anchored area Duringthe anchor working the trend of zonal disintegration whichinduces it shows the tension and compression alternation

6 Conclusion

(1) Under high axial geostress zonal disintegration phe-nomena occur in the nonanchored area while it didnot occur in the fully anchored area It indicatesthat anchoring suppresses the zonal disintegrationobviously

(2) The radial strain of surrounding rocks displays thefluctuation state where wave crest and rough arrangein interval both in anchored and nonanchoring area


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5

(a) Nos 1ndash5 anchor strain changing with excavation steps

0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

Anchor 6Anchor 7Anchor 8

Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)

(b) Nos 6ndash10 anchor strain changing with excavation steps

0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)

(c) Nos 11ndash15 anchor strain changing with excavation steps

Figure 17 Anchor strain changing with the excavation steps Note No 12 anchor was damaged during the test and the data could not berecorded

(a) The non-anchoring half model

Anchor

Fractured zone

Anchor

(b) The anchored half model

Figure 18 Failure distribution of the surrounding rock mass after tunnel excavation


First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r

Figure 19 Elastoplastic geostress fields in surrounding rock massand forming process of zonal disintegration

It indicates that the deep rock masses have the trendof zonal disintegration under the high axial geostress

(3) The tension and compression alternation phenom-enon of anchor is observed during the tunnel exca-vation procedure This special phenomenon is dif-ferent from the shallow buried tunnel It indicatesthat the trend of zonal disintegration exists in thedeep tunnel The reinforcement of anchor suppressesthe occurrence of zonal disintegration During thework of anchor it shows the alternation of tensionand compression It indicates that the mechanicalbehavior of the surrounding rocks is nonmonotonic

The anchor suppresses the growth of zonal disintegrationso the optimization of parameters and disposal of anchor areof great importance to the stability of deep tunnelThe furtherstudy is needed to conduct in the future

Acknowledgments

This work was supported by the National Natural Sci-ence Foundations of China (Grant nos 51209074 and41172268) China Postdoctoral Science Foundation (Grantnos 2012M511189 and 2013T60494) and the FundamentalResearch Funds for the Central Universities (Grant no2012B02714) supported by State Key Laboratory for Geome-chanics and Deep Underground Engineering China Univer-sity of Mining amp Technology under Grant SKLGDUEK1206the Open Research Fund of State Key Laboratory of Geome-chanics and Geotechnical Engineering and the Institute ofRock and Soil Mechanics Chinese Academy of Sciencesunder Grant no Z012008 and funded by CRSRI OpenResearch ProgramCKWV2012306KY by the Key laboratoryof coal-based CO

2capture and geological storage Open

Research Program 2012KF08The authors are deeply gratefulfor these supports

References

[1] E I Shemyakin G L Fisenko M V Kurlenya et al ldquoZonaldisintegration of rocks around underground workings part IIrock fracture simulated in equivalent materialsrdquo Soviet MiningScience vol 22 no 4 pp 223ndash232 1986

[2] Q H Qian ldquoThe characteristic scientific phenomena of engi-neering response to deep rock mass and the implication ofdeepnessrdquo Journal of East China Institute of Technology vol 27no 1 pp 1ndash5 2004

[3] G R Adams and A J Jager ldquoEtroscopic observations of rockfracturing ahead of the stope faces in deep-level gold minesrdquoJournal of the South Africa Institute of Mining and Metallurgyvol 21 no 2 pp 115ndash127 1980

[4] E I Shemyakin G L Fisenko M V Kurlenya et al ldquoZonaldisintegration of rocks around underground workings part 1data of in situ observationsrdquo Soviet Mining Science vol 22 no3 pp 157ndash168 1986

[5] E I Shemyakin G L Fisenko M V Kurlenya et al ldquoZonaldisintegration of rocks around underground mines part IIItheoretical conceptsrdquo Soviet Mining Science vol 23 no 1 pp1ndash6 1987

[6] E I Shemyakin M V Kurlenya V N Oparin et al ldquoZonaldisintegration of rocks around underground workings IVPractical applicationsrdquo Soviet Mining Science vol 25 no 4 pp297ndash302 1989

[7] E J Sellers and P Klerck ldquoModelling of the effect of discon-tinuities on the extent of the fracture zone surrounding deeptunnelsrdquo Tunnelling and Underground Space Technology vol 15no 4 pp 463ndash469 2000

[8] D F Malan and S M Spottiswoode ldquoTime-dependent fracturezone behavior and seismicity surrounding deep level stoppingoperationsrdquo inRockbursts and Seismicity inMines S J Gibowiczand S Lasocki Eds pp 173ndash177 A A Balkema RotterdamTheNetherlands 1997

[9] X Zhou Q Qian and B Zhang ldquoZonal disintegration mech-anism of deep crack-weakened rock masses under dynamicunloadingrdquoActaMechanica Solida Sinica vol 22 no 3 pp 240ndash250 2009

[10] J Gu L Gu A Chen J Xu and W Chen ldquoModel test studyon mechanism of layered fracture within surrounding rock oftunnels in deep stratumrdquoChinese Journal of RockMechanics andEngineering vol 27 no 3 pp 433ndash438 2008

[11] Y Pan Y Li X Tang and Z Zhang ldquoStudy on zonal desin-tegration of rockrdquo Chinese Journal of Rock Mechanics andEngineering vol 26 supplement 1 pp 3335ndash3341 2007

[12] X Tang Y S Pan and M T Zhang ldquoMechanism analysis ofzonal disintegration in deep level tunnelrdquo Journal of GeologicalHazards and Environment Preservation vol 17 no 4 pp 80ndash842006

[13] L S Metlov A F Morozov and M P Zborshchik ldquoPhysicalfoundations of mechanism of zonal rock failure in the vicinityof mine workingrdquo Journal of Mining Science vol 38 no 2 pp150ndash155 2002

[14] S Li Q Qian D Zhang and S Li ldquoAnalysis of dynamic andfractured phenomena for excavation process of deep tunnelrdquoChinese Journal of Rock Mechanics and Engineering vol 28 no10 pp 2104ndash2112 2009


[15] M A Guzev and A A Paroshin ldquoNon-Euclidean model of thezonal disintegration of rocks around an underground workingrdquoJournal of Applied Mechanics and Technical Physics vol 42 no1 pp 131ndash139 2001

[16] M Wang H Song D Zheng and S Chen ldquoOn mechanism ofzonal disintegration within rock mass around deep tunnel anddefinition of lsquodeep rock engineeringrsquordquo Chinese Journal of RockMechanics and Engineering vol 25 no 9 pp 1771ndash1776 2006

[17] M-Y Wang P-X Fan and Z K Guo ldquoElastoplastic model fordiscontinuous shear deformation of deep rock massrdquo Journal ofCentral South University of Technology vol 18 no 3 pp 866ndash873 2011

[18] Y He B Jiang L Han P Shao and H Zhang ldquoStudy of inter-mittent zonal fracturing of surrounding rock in deep roadwaysrdquoJournal of ChinaUniversity ofMining andTechnology vol 37 no3 pp 300ndash304 2008

[19] X Zhou and Q Qian ldquoZonal fracturing mechanism in deeptunnelrdquoChinese Journal of RockMechanics and Engineering vol26 no 5 pp 877ndash885 2007

[20] X Zhou Q Qian and H Yang ldquoEffect of loading rate on frac-ture characteristics of rockrdquo Journal of Central South Universityof Technology vol 17 no 1 pp 150ndash155 2010

[21] X P Zhou H F Song and Q H Qian ldquoZonal disintegrationof deep crack-weakened rock masses a non-Euclidean modelrdquoTheoretical and Applied Fracture Mechanics vol 55 no 3 pp227ndash236 2011

[22] Q Qian X Zhou and E Xia ldquoEffects of the axial in situ stresseson the zonal disintegration phenomenon in the surroundingrock masses around a deep circular tunnelrdquo Journal of MiningScience vol 48 no 2 pp 276ndash285 2012

[23] X P Zhou G Chen and Q H Qian ldquoZonal disintegrationmechanism of cross-anisotropic rock masses around a deepcircular tunnelrdquo Theoretical and Applied Fracture Mechanicsvol 57 no 1 pp 49ndash54 2012

[24] X P Zhou and J Bi ldquoZonal disintegration mechanism ofcross-anisotropic rock mass around a deep circular tunnelunder dynamic unloadingrdquo Theoretical and Applied FractureMechanics vol 60 no 1 pp 15ndash22 2012

[25] V N Reva and E A Tropp ldquoElastoplastic model of the zonaldisintegration of the neighborhood of an underground work-ingrdquo in Physics and Mechanics of Rock Fracture as Applied toPrediction of Dynamic Phenomena (Collected Scientific Papers)pp 125ndash130 Mine Surveying Institute Saint Petersburg Russia1995

[26] Y L Tan J G Ning and H T Li ldquoIn situ explorations on zonaldisintegration of roof strata in deep coalminesrdquo InternationalJournal of Rock Mechanics and Mining Sciences vol 49 pp 113ndash124 2012

[27] H Wu Z Guo Q Fang Y Zhang and J Liu ldquoMechanismof zonal disintegration phenomenon in enclosing rock massaround deep tunnelsrdquo Journal of Central South University ofTechnology vol 16 no 2 pp 303ndash311 2009

[28] VNOdintsev ldquoMechanismof the zonal disintegration of a rockmass in the vicinity of deep-level workingsrdquo Journal of MiningScience vol 30 no 4 pp 334ndash343 1994

[29] B V Laptev and R P Potekhin ldquoBurst triggering by zonaldisintegration of evaporitesrdquo Soviet Mining Science vol 24 no3 pp 238ndash241 1988

[30] E Fumagalli Statical and GeomechanicalModels Springer NewYork NY USA 1973

[31] E Fumagalli ldquoGeomechanical models of dam foundationrdquo inProceedings of the International Colloquium on Physical andGeomechanical Models Bergamo Italy March 1979

[32] Z Fang ldquoSupport principles for roadway in soft rock and itscontrolling measuresrdquo in Soft Rock Tunnel Support in ChineseMinesTheory and Practice H EManchao Ed pp 64ndash70 CoalIndustry Publishing Press Beijing China 1996 (Chinese)

[33] C Fairhurst and N G W Cook ldquoThe phenomenon of rocksplitting parallel to the direction of maximum compression inthe neighborhood of a surfacerdquo in Proceedings of the 1st Congressof the International Society for Rock Mechanics pp 687ndash692Lisbon Portugal September 1966

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



Zonal disintegration phenomenon differs from the engi-neering response in shallow rock excavation and as such can-not be explained perfectly under the framework of traditionalrock theory In accordance with the concepts of traditionalcontinuum mechanics the enclosing rock mass around adeep tunnel is divided into fractured plastic and elasticregions from the periphery of the tunnel to infinity Zonaldisintegration a characteristic of deep rock masses has beenthe focus of recent investigations

A number of experts have used various methods toexplain zonal disintegration Sellers and Klerck [7] indicatedthat the discontinued surface could be one of the derivationsof zonal disintegrationMalan and Spottiswoode [8] analyzedthe relationship between the shock bump and the zonaldisintegration of a top plate in the surrounding rocks ofa mining field Zhou et al [9] investigated the dynamicexcavation of a deep tunnel to determine the residual strengthand the forming time of fractured zones Gu et al [10] con-ducted a compression test on cylinder specimen and regardedaxial stress as an important factor for zonal disintegrationOther studies on zonal disintegration have applied differenttechniques such as a series of compression tests Pan [1112] nonequilibrium thermodynamics (Metlov et al) [13]Hamiltonian time-domain variation (Li et al) [14] and thenon-Euclideanmodel (Guzev and Paroshin) [15] In additionsome elastic-plastic theories have been adopted to analyzethe forming mechanism of zonal disintegration (Wang et al[16 17] He et al [18] Zhou et al [19ndash24] Reva and Tropp[25] Tan et al [26] Wu et al [27] Odintsev [28]) A zonaldisintegration phenomenon is shown in Figure 1

Zonal disintegration is a unique failure phenomenonposing a large-scale disaster during excavation of deep rockmasses (Laptev and Potekhin) [29] It threatens the stability ofdeep tunnel and will cause large collapse of rock mass whichinduces a great loss It is of great importance to know theanchoring effect on zonal disintegration and the mechanicalbehavior under anchoring condition in deep rock massesfor the stability of deep tunnel To the authorsrsquo knowledgeanchoring effect on zonal disintegration phenomenon indeep rock masses is not investigated previously

In this paper the Huainan coal mine in which zonaldisintegration occurs in China was taken as the engineeringbackground The model tests on zonal disintegration werecarried on in the condition of anchoring and without anchor-ing in separate The model was built using an independentlydeveloped barites-iron-sand cementation analogical (BISA)material Through the analogical model test the damagepattern with and without anchoring was observed Thenonlinear deformation changing laws were clarified by usinga precise optical apparatus Based on this the anchoring effectand forming condition of zonal disintegration in deep rockmasses is revealed

2 Similarity Theory and Analogical Material

The geomechanical model test is an important scientific re-search method Similar to prototype engineering the modelwas designed based on the similarity principle An optical

Stands for fractured zoneStands for intact zone

Figure 1 Sketch of the zonal disintegration phenomena in deeptunnel

measuring apparatus was used in the geomechanical modeltestThe stress and displacement changing rules of the modeland strain of the anchor were monitored to determine thedeformation laws of prototype engineering The model testexhibits an advantage in studying the failure mechanism ofunderground cavities over in situ observation which relieson auditory-visual perception and is time-consuming

The geomechanical model test is an effective reducedscale method used for investigating special engineeringproblems based on the similarity principle The changinglaws of stress strain and displacement can be monitored bydesigning the model similar to that of prototype engineeringFollowing the similarity principle the data observed from themodel test can be used to reveal the stress distribution lawsand themechanism in prototype engineering thereby solvingactual problems

21 SimilarityTheory Thegeomechanicalmodel test requiresa suitable similar material that can reflect the mechanicalbehavior of a rock type The similar material and its proto-type must comply with the similarity principle The theoryrequires several similarity coefficients defined as ratios ofprototype parameters to model parameters to be constant(Fumagalli) [28 30]

119862120590= 119862120574119862119871 (1a)

119862120575= 119862120576119862119871 (1b)

119862120590= 119862120576119862119864 (1c)

119862120576= 1 119862

119891= 1

119862120601= 1 119862

120583= 1

(1d)




where 119862120590 119862120576 119862119864 119862119871 119862120574 119862119891 119862120601 and 119862












1 11 042 25 75 50











Iron powder Cement


Barites powder


(b)

(e)

(a)

(d)

(c)

(f)



Strain gauge

(a) (b)


2

34

1

5

6

(a)

2

34

1

5

(b)















120582119861= 2119899effΛ (2)





Δ120582119861= 120582119861(1 minus 119875

119890) 120576 = 119870

119890120576 (3)






120576 =Δ119897

119897=Δ120582

120582 (4)








119871









34

2

1


1

4

3


1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7







TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation












where 119862120590 119862120576 119862119864 119862119871 119862120574 119862119891 119862120601 and 119862












1 11 042 25 75 50











Iron powder Cement


Barites powder


(b)

(e)

(a)

(d)

(c)

(f)



Strain gauge

(a) (b)


2

34

1

5

6

(a)

2

34

1

5

(b)















120582119861= 2119899effΛ (2)





Δ120582119861= 120582119861(1 minus 119875

119890) 120576 = 119870

119890120576 (3)






120576 =Δ119897

119897=Δ120582

120582 (4)








119871









34

2

1


1

4

3


1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7







TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Iron powder Cement


Barites powder


(b)

(e)

(a)

(d)

(c)

(f)



Strain gauge

(a) (b)


2

34

1

5

6

(a)

2

34

1

5

(b)















120582119861= 2119899effΛ (2)





Δ120582119861= 120582119861(1 minus 119875

119890) 120576 = 119870

119890120576 (3)






120576 =Δ119897

119897=Δ120582

120582 (4)








119871









34

2

1


1

4

3


1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7







TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Strain gauge

(a) (b)


2

34

1

5

6

(a)

2

34

1

5

(b)















120582119861= 2119899effΛ (2)





Δ120582119861= 120582119861(1 minus 119875

119890) 120576 = 119870

119890120576 (3)






120576 =Δ119897

119897=Δ120582

120582 (4)








119871









34

2

1


1

4

3


1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7







TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation















120582119861= 2119899effΛ (2)





Δ120582119861= 120582119861(1 minus 119875

119890) 120576 = 119870

119890120576 (3)






120576 =Δ119897

119897=Δ120582

120582 (4)








119871









34

2

1


1

4

3


1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7







TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










34

2

1


1

4

3


1

2

3

4

4

5

5

6

7

89

10

(c) Sketch diagram

7







TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation












TunnelExcavate

Anchor

is for strain

IIIII I

60 cm

60 cm

15 cm


IIIII I






Loadingdirection

Self-weightstress




Loadingdirection

Self-weightstress











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











(b) Burying of GRDS


B (7)

A (8)

B (7)

A (8)

B (7)

A (8)

B (7)

A (8)





(b) Section sketch





119903turns to








The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













The loading state

120590z

120590x 120590x

120590y

120590z

(a) (b)









(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











(c) Grouting

Anchor

(d) Anchor finished











Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Tunnel

Multimeters

(a) Layout sketch

654321

Arc

crow

n

01


0

05

05

05

11

01

654321

0051 InvertD (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel


654321

0051152

123456 6543210051152

115

0

654321

0051152Invert


Arc

crow

n

D (mm)

D (mm)

D(m

m)

D(m

m)

Tunnel













Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Invert

Arc

crow

n

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Strain (120583120576)

Tunnel


654321

05001000


0

500

1000

70

500

1000

7

7

234567

1

05001000

Measuring points

Mea

surin

g po

ints

Mea

surin

g po

ints

Strain (120583120576)

Stra

in (120583

120576)

Stra

in (120583

120576)

Strain (120583120576)

Tunnel






6 Conclusion




0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps

minus100

minus50

Stra

ins (120583120576)

No 1No 2No 3

No 4No 5


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

50

100

150

200

Excavation steps


Anchor 9Anchor 10

minus100

minus50

Stra

in (120583

120576)


0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

Excavation steps

Anchor 11Anchor 13

Anchor 14Anchor 15

minus100

Stra

in (120583

120576)




Anchor

Fractured zone

Anchor




First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










First fracture

Second fracture

120590r

120590r

120590max120579

120590max120579

RpRp

Rp

120590120579

120574H

R998400p

R998400p

120590

r

ra

120590998400

r





Acknowledgments




References





































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









Research Article Model Test of Anchoring Effect on Zonal...

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