BOUNDARIES OF ROCK MECHANICS pdf

On the basis of field geological survey, in-situ stress measurement rock mechanics test and FEMnumerical simulation, the stress distribution law in the tunnel area is comprehensively ana

BOUNDARIES OF ROCK MECHANICS

BALKEMA – Proceedings and Monographs

in Engineering, Water and Earth Sciences

PROCEEDINGS OF THE INTERNATIONAL YOUNG SCHOLARS’ SYMPOSIUM ON ROCKMECHANICS, 28 APRIL–2 MAY, 2008, BEIJING, CHINA

Boundaries of Rock Mechanics

Recent Advances and Challenges for the 21st Century

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ISBN: 978-0-415-46934-0 (hbk)

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

Table of Contents

Field investigation and instrumentation

Stress field characteristics and prediction of rockburst in the tunnel area

M.F Cai, X.O Xia, H Peng & X.M Ma

Identification of geological interfaces from drilling process monitoring in ground investigation 7

W Gao, J Chen & Z.Q Yue

C.L Li & X.L Li

In situ stress state in engineering area of Dali-Lijiang railway and its impact on the railway project 19

X.M Ma, H Peng & J.S Li

H Peng, Z.H Wu & X.M Ma

Stain monitoring for tunnel using distributed optical fiber BOTDR sensors 27

H.T Qiu, C Li, H.L Cui, D Zhang & Y Ding

B Wang, Y.F Gao, J.Y Jia, F Xing & Y.P Zhang

A comparison of evaluation of rock mass deformation modulus from in-situ method

N.S Zadeh

Rock properties and mechanical behavior

Stress and scale effects of the hydraulic properties of fractured rocks 41

L Jing & A Baghbanan

Experimental study on deformation of deep unsaturated-saturated Tuff in Lancang lead-deposit 49

G.Z Cao, Y Qiang & F Li

Detection of thin weak zone in weathered rocks from automatic monitoring of pneumatic

J Chen, W Gao & Z.Q Yue

Study on porosity changes of Longyou sandstone under chemical corrosion 59

Q Cui, X.T Feng, C.Q Zhang, Q Xue, H Zhou & Z.H Zhang

A thermomechanical damage approach of constitutive models and its application in geomaterials 67

X Guo, D.J Yuan, M.S Wang & C.G Zhao

Numerical lower bound analysis of stability problems of rock and soil masses 73

C.Q Jia, Q.W Huang & M.S Huang

Dynamic response to incident body waves of cylindrical cavities in a porous medium half-space 79

L.F Jiang, Y.Y Jiao & X.L Zhang

Elasto-plastic analysis of jointed rock masses using the numerical manifold method 83

J Jiao & C.S Qiao

E.E Kheirelseed, T.H Ming & S.B Abdalla

Research on rock mechanics parameters by using comprehensive evaluation method

Y Li, S.R Wang, C.F Wu, H.Q Zhang & Z.F Li

SEM microstructure and SEM mechanical tests of swelling red sandstone in

B Liu, L.G Tao, T Li, G.G Qiao, J Chen & J.H Yan

Application of laser real-time HI to investigation of mesomechanical behaviors of rock 105

D.M Liu & Y.B Zhou

The effect of meso-structure on temperature distribution in shale subject to freeze-thaw conditions 109

H Liu & G.S Yang

The installation method and test of rock deformation in deep borehole by fiber bragg grating 115

J.X Liu, J Chai, L Zhui, Y Li, G.W Zhang, J.H Yang & Z.P Wang

Numerical study on size effect of ring specimen under Brazilian test 121

W.B Liu, B.G Liu & K.Y Liu

Laboratory comparative tests for geomaterial strengths with drilling process monitoring technique 127

W.J Lu, T.Y Lau & Z.Q Yue

Experimental investigation on multidirectional loading under different initial stress states in clay 133

M.T Luan, Y Nie, X.W Tang, B.X Liu, J.Y Li & J.B Fu

Investigation of rock resistance coefficient in rocks around tunnel based on unified strength theory 139

Q Ma, J.H Zhao & X.Y Wei

Elimination of end friction in biaxial testing of cubic rock samples 145

H.S Mitri, X.Y Yun & X.L Yang

Study on the dominant factors for primary fissure form in the process of hydraulic

X.M Ni, Y.B Wang, B.Z Yan & Q.H Hu

Real-time CT testing of meso-damage evolution law of frozen cracked sandstone under

J.X Ren & H Liu

Study of similarity recognition of drilling parameters in weathered granite formations 161

Z.Y Tan, M.F Cai & S.J Wang

Stress solutions for an inhomogeneous plane strain transversely isotropic rock

C.D Wang & J.Y Hou

Precision analysis of discontinuity orientation obtained with DCRP 173

F.Y Wang, J.P Chen & B.F Shi

L.G Wang, N Zhao, L.L Zhang & Y.F Zhou

M Wang, Q Yang, G.Q Kong & M.T Luan

VI

Characterization of mechanical properties of rocks by microindentation test—A new method

W Wang, W.Y Xu, S Corn & P Ienny

Numerical simulation of acoustic emission and strain energy decrease of rock specimens

X.B Wang

Study on judge system of fuzzy inference to classification of tunnel surrounding rock 203

X.R Wang, Y.H Wang & S.H Zhang

Research on ultrasonic characteristics of sandstone after heating to high temperature 207

G Wu & S Liu

Study on crack initiation mechanism of brittle rock under pressure head 213

K.S Wu, J.F Gu, Y.X Yang, Z.M Zhai, C.B Yu, H.P Tian, G.Z Guo & Z.Y Shao

L.Q Yang, S.R Zhang & J.Q Wu

Numerical simulation of the morphology and the geometric characteristic

X Yang, P Zhang & N Li

D.J Yuan, Q.F Huang & A Koizumi

X.Y Yun, X.L Yang & H.S Mitri

Research on mechanical characteristics of damage in surrounding rock mass with high geo-stress 239

J.X Zhang, H.D Jiang, X.H Ren, J.Q Shu & H.Y Ren

Surface roughness analysis of rock joints based on a 3D surface model 243

P Zhang, N Li & X Yang

Study on mechanical properties of rock discontinuity during unloading 249

Q.Z Zhang, M.R Shen & L.B Zhang

Study on physical and mechanical properties of the coal gangue for filling 255

X.G Zhang, H.L Wang & Z.P Liu

Numerical simulation of crack propagation in three-point bending beams 259

X.L Zhang & Y.Y Jiao

Z.G Zhao, Y.L Tan & Q.T Hu

Processing and experimental technology of 3-D cracks in brittle materials 267

X Zhu, M.L Huang & Y Huang

Numerical simulation of crack propagation in a rock mass under seepage-stress coupling conditions 273

N Zhuang, K.Z Zhu & J.W Li

Underground mining and excavation engineering

W.X Chen, X.Q He, H.S Mitri & B.S Nie

Destressing design and practice of a soft rock roadway under high ground pressure 287

F.L He, B Du, S.B Zhang & S.R Xie

Grouting experiment on forming artificial Pillar for Pillar stoping 291

K.P Hou, M Xie & K.G Li

Asymmetrical bolt-mesh support technique of deep soft-rock roadway under complex conditions 295

M.L Huang, W Lu, F Wang & T Xu

B.S Jiang & J.G Wang

Predictive analysis of dynamic instability for Large-Scale-Mined-out-Area (LSMA)

based on field hybrid monitoring in western strong seismic region 307

X.P Lai, M.F Cai, F.H Ren & S.J Miao

Research on the variation rule of working face support pressure beneath igneous strata 313

W Li, H.G Ji, J.A Wang & S.J Cai

Prediction on subsidence area developing situation of steep inclined coal seem 317

W Li, J.A Wang & T.J Xu

X.L Li & C.L Li

Infiltration mechanism of mine water from abandoned mines through coal rock mass 325

X.L Li, L Liu, L.G Wang & T.G Deng

Numerical simulation of splitting failure of Pubugou hydropower station based on energy method 329

N Liu, W.S Zhu, X.J Li & X.L Xin

Stability of coal mine roadway intersection in great depth of cover 333

T.K Lu & X Chen

Rapid excavation by blasting technique for hard rock roadways in high gas coal mine 339

Q.Y Ma & S.J Miao

Construction of Chongwenmen station passing under existing subway with underground

S.Z Ma & C.S Qiao

Effects of geometrical characteristic on cavern integrity for the underground gas storage 349

J Mo, W.G Liang & Y.S Zhao

Numerical analysis of the capability of water-resisting key strata to prevent water seepage

H Pu & X.X Miao

Modeling study of roadway stability in Xishimen iron mine based on yielding approach index 359

L Qiao, S.Y Li, W Gao & L.Y Zhu

Time series analysis of ground surface displacement induced by tunnel excavation 363

S.W Qin, J.P Chen, Y.H Xiao & J.S Que

P Sheng, G.Y Yu & Y.Y Duan

Analysis and evaluation aspects on stability of water-sealed underground petroleum

H.B Shi & B.G Liu

Study on the application of discrete wavelet on the risk diagnose of surrounding rock

B Song, J.S Pan & P.F Wang

Visco-elasto-plastic simulations for coal pillar stability affected by mining 383

Y.L Tan, C.J Sun, Z.K Wu & Y.J Chen

G.R Teng, Y.L Tan & M Gao

VIII

Mechanical and experimental study on the failure law of massive igneous rock in the

X.W Wei, H.G Ji, J.A Wang, L Qiao & X.W Wei

The unloading model of the rock masses and its application on numerical analysis of

X.L Wen & X.M Guo

H.W Wu, S.J Miao & H.T Ma

S.L Xu, H.H Zhu, Z.G Yan & W.Q Ding

Three-dimensional strain softening modeling of sublevel open stope method layouts 415

G.T Yang, X.B Li, Q.S Wang, X.L Liu & H.J Chen

Mechanism of mining-induced horizontal fractures in overburden strata 419

G.M Yu, C.F Yuan, X.G Zang, S.B Lu, G.Y Wang, Z.J Su & X.L Fan

Rock heat-transfer model of high-temperature stopes and its solving process 425

F.L Zhan & M.F Cai

Grid computing for large-scale underground cavern group based on Krylov subspace methods 429

L Zhang & H.D Jiang

Study on the silting mechanism of reinforcing extraordinary cracked coal body using polyurethane 435

S.T Zhang, R.J Si, Y.H Zou & Z.H Yang

Influence of cavern space on stability of large cavern groups under earthquakes 439

B.Y Zhao, Z.Y Ma, W Xu, C.Y Jin & Z.G Yang

Study on the evolution of stress in shaft-lining during stratum-grouting 447

G.S Zhao, G.Q Zhou, X.Y Shang, F.P Zhu, B.B Xu, X.J Li, Z.L Yin & G.Q Dong

Rock slopes and landsides

Case study of slope stabilization using compression anchor and reinforced concrete beam 455

G.Z Chen & J.Q Jia

Reliability assessment of an open-pit slope using finite element strength reduction method and

J Deng, Z Peng & D.S Gu

Designing, constructing and monitoring of slopes in rock mass in Croatia 463

M Groši´c, S Dugonji´c & D Udoviˇc

Analysis of rock slope stability by using the strength reduction method 471

M He, N Li, Q Liu & J.G Hao

Application of accelerating genetic algorithm combined with golden section in slope stability analysis 477

H Hu, L Yao & M Dong

The reliability analysis of Nantong coal gangue slope based on the modified ‘JC’ method 483

D.S Li & D.Y Liu

Stability analysis of cutting slope by using 3D dynamic numerical simulation 487

K.G Li, K.P Hou & Y Cheng

S Li, S.Q Wang & S.L Liu

Stability of slope and stope of transition from opencast mining to underground mining 497

Z.J Li, G.G Qiao, Z.J Li, Y.B Zhang, G.Q Gan, X.Y Mi & G Chen

Rock slope stability analysis with nonlinear finite element method 503

Y.R Liu, Q Yang, L.J Xue & W.Y Zhou

Y.Z Liu, X.R Ge, C.G Li & S.H Wang

Combination of probabilistic and deterministic methods for three-dimensional assessment

C Qiu, M Xie, T Esaki & Y Mitani

Strength characteristic of loess with different structure and its application to analyzing

S.J Shao & G.H Deng

Influence of underground water on the stability of jointed slopes 527

W.H Tan, S.J Miao & F.H Ren

Analysis of the formation mechanism of Xiamen subsea tunnel fault 533

J.S Wang, Y Li, L Wang, Z.G Cao, Y.X Zhang & Z.F Li

Evaluation on country rock quality of tunnel based on set pair analysis 539

Q.S Wang, G.X Wang & X.B Li

X.B Xiong, M.X Zheng, P Lin, Y.F Du & B Wang

Application of GPS technology to sliding slope deformation monitoring 547

M.L Xu & F.Y Yang

Study on the stability of pusiluogou engineering slope in right bank 551

P.H Xu, J.P Chen, R.Q Huang, M Yan, M.F Gong & J.P Zhou

K Yang, C Shi & J.F Wang

Z.J Yang, M.F Cai, S.J Miao & Y Liu

Artificial neural network based predicting model for evaluating stability of landslide 567

B Zeng & W Xiang

H Zhang, Z.X Zhang, H.W Huang & J.K Zhou

Deformation and reinforcement of a rock slope in the anticline center 579

L Zhang, L.J Tao & G.Y Wei

Chaotic particle swarm optimization for non-circular critical slip surface identification

H.B Zhao, Z.S Zou & Z.L Ru

In-situ test and study of the internal force features of prestress anchor lattice beam 589

D.P Zhu, Y.Z Xu, E.C Yan & W Xiao

Tunnels and foundations

H.M Chen & F.X Sun

Calculation and analysis of plastic zone and ground settlement for shield tunnel 603

Y Chen & Q.H Zhang

Z.Y Fan, H.W Huang & D.M Zhang

X

Probabilistic determination of the principal parameters controlling the ground settlement

L.Y Gu, H.W Huang & W Chen

Influence of the distribution of a concealed fault on stability of tunnel 617

P Jia & C.A Tang

Application of neutral point theory on designing free segment length of pre-stressed

A.B Jin, Y.T Gao & S.C Wu

Uplift capacity of single piles embedded in clay: Prediction and application 625

G.Q Kong, Q Yang, M Wang & M.T Luan

Numerical analysis for a strain softening behavior of a shallow NATM tunnels 631

J.H Lee, G.R Jin, J.S Shin, J.H Park, S.G Choi, Y.Y Na, Y.S Jeon & I.H Jeng

Deformation analysis by artificial neural networks and FEM database for design and

J.H Lee, Y.S Kim, G.R Jin, T.S Kwon, W.S Hwang, H.S Han, S.U Shin, S.J Park & I.S Seo

Effect of measurement error on the accuracy of the predicted value of the three-point method 645

L Li & W.D Liu

Field instrumentation and 3-D numerical modeling on two adjacent metro shield

T Li, B Liu, Y.S Jiang & L.G Tao

Influence of intermediate principal stress on seismic stability of rock-fill dams 655

Y.L Lin & H.L Liu

Study on deformation control technique in deep foundation pit engineering 661

H Liu & M.F Cai

Study on the GA-ANIFIS intelligence model for nonlinear displacement time series analysis

K.Y Liu, C.S Qiao & S.D Wang

Dynamic testing study of the precast assembled electrical manhole 673

P.F Mu, X.Y Xie, Z.X Zhang, H Zhang & C Wang

L.H Song, L Mei, G.X Mei & J.M Zai

Parameter equivalent for Mohr-Coulomb and Hoek-Brown criteria in the case of rock tunneling 683

X.J Tang, Y.H Wang & Y Wang

Theoretical and experimental study on bearing characteristics of super-long rock-socketed

H.Z Wang, R Cao, Y.W Zeng & B Zhu

3-D stability analysis of tunnel structures based on geometric stochastic blocks theory 695

S.H Wang, Y.B Zhang, N Zhang & S Wang

Research on stability of the mined-up region for prebuilding steelworks 701

S.R Wang, C.F Wu, Y Li & Z.F Li

Calculation of permeability tensor of fractured rock mass based on statistics and its application

T.H Wang, J.P Chen, Q Wang & Y Li

Tunnel invert heave and the principles of its control: A study from Yunling tunnel 711

Y Wang, Y.H Wang & X.J Tang

Prediction of surrounding rock pressure of Maanshan tunnel by the method of support vector machine 715

Y.H Xiao, Q Wang, J.P Chen, W.K Dai & J.S Que

D.S Xu, Y Wang & R.C Xiao

Study on the key techniques of tunneling across underground river in Karst areas 727

Y.G Xue, S.C Li, S.C Li, Q.S Zhang, B Liu & Q Liu

Torsional dynamic analysis of a rigid foundation on a non homo-geneous saturated stratum 731

Y.F Yang & D.Z Wu

A new method for vibration response of beam on foundation under moving load 737

Y.Z Yang & X.R Ge

Dynamic superposition of tri-anchor support technology at tunnel junction under complex

H.Q Zhang, Y.N He, L.J Han, B.S Jiang, M.L Zhang, J.G Wang, L.H Li & Y.J Lin

Research on the settlement prediction models of combined piles composite foundations 749

L.H Zhang & S.F Zhao

Model test and numerical simulation of tunnel in country rocks with faults 755

N Zhang, S.H Wang, B Yang & W.H Liu

Freezing damage prevention and forecast to roads on congealed ground 759

X.D Zhang, Y Pan & Y.B Gong

Mining of coal seam under mined out space and foundation stability of transmission tower 765

Y Zhang, M.F Cai, Y.Y Zhao & P Luo

Application of synthesized methods for stability analysis of rock cavern foundation 769

Y.X Zhang, T.Q Zhou & G.L Wang

Mechanism of interaction between tunnel and slopes in Portal construction 775

X Zhao, C.C Xia & C.B Xu

FBG-based health monitoring for the secondary lining of Bainijing tunnel No.3 in Kunming, China 781

X.G Zhao, H.T Qiu, C Li & J.P Liu

Self-adaptable end-bearing composite pile foundation and its application in situ 787

F Zhou, J.M Zai & G.X Mei

Investigation of coupled stress and seepage of a reservoir completely covered by geomembrane 791

J.F Zhou, X.M Guo, X.F He, K.D Tang & J.M Hu

Application of transient electromagnetic method in colliery hydraulic channels 795

W Zuo & J.A Wang

Dynamics and blasting

Extensional method of rockburst and its application in Huangdao water sealed underground oil tank 803

X Chen, X.B Qi, J.Z Sun & J.K Zhang

Study on electromagnetic radiation forecast for rock burst with hard roof 811

B Du, J.M Yao & F.L He

Numerical simulation on penetrating rock by linear shaped charge jet with uneven thickness cover 815

A.P Fei & L.J Guo

Effects of soil characteristics on seismic-induced pore water pressure around

M.T Luan & X.L Zhang

XII

Numerical study of the effect of ground stress on coal bursting potential 825

J.N Pan, Z.P Meng, Q.L Hou & Y.W Ju

Research on rockburst prediction with fuzzy comprehensive evaluations based on rough set 831

D.H Qiu, J.P Chen, Q Wang & J Zhang

Dynamical destabilization experimental analysis on deep-seated, steep and heavy thick coal

F.H Ren, L.J Zhang & X.P Lai

Analysis of 3-D seismic response of subway station structures in Wuhan 843

G.B Wang, W.P Xie & X.F Ma

Study on blasting seismic safety criterion based on wavelet packets equivalent energy technique 847

X.Z Wu, K Zhao & M.F Cai

Investigation of comprehensive rockburst prediction during deep mining 851

M.G Xu, G.H Yao, Z.H Ouyang & Z.J Du

Countermeasure research on preventing rock burst with hard roof by energy mechanism 857

J.M Yao & F.L He

Study on the influence of surrounding rock to the tunnel excavation by numerical simulation 861

Y.Q Yu, X.L Yang, W.M Liang & M.Y Hu

Seismic response of QINGDAO sub-sea tunnel considering transversely isotropic 867

X Zhang, S.C Li & X.L Ding

Microcosmic mechanism analysis and experimental study of rock burst fracture based on SEM 873

Y.B Zhang, Y.B Zhang, Z.Q Kang & F.P Li

New techniques and methods

J Guo, Y.H Wang & Y Miao

C.H Huang, X.G Xie, D.H Xie & T Feng

Y.Y Jiao, X.L Zhang, S.L Wang & J Zhao

Study on the ecological protection techniques of steep rock slope in high-cold area 895

T.B Li, H Xu, R.B Zhang & X.H Zhou

A splitting failure criterion of surrounding rock mass in depth of high in situ stress region and

X.J Li, W.S Zhu, W.M Yang & Y Li

Development of a new type of steel structure rack apparatus for 3D geomechanical model

Y Li, W.S Zhu, Q.Y Zhang, H.P Wang, W.T Wang & J Han

DEM simulation of shear bands using a meshfree strain calculation method 913

Y Liu, S.C Wu, F Li & X.Q Chai

Deformation prediction research based on improved Saito’s method with Verhulst grey model 919

S.J Miao, W.H Tan, Z.F Hou & P.L Li

Electromagnetic emission characteristics and mechanism of the deformation and fracture of coal 925

B.S Nie, X.Q He, W.X Chen & F.B Liu

A research about the feasibility of cement grouting to reinforce petty crack rock 931

W.G Qiao, Y.Q Zhang, V.V Perchine & A.V Ouglianitsa

3D modeling and visualization of complex geological structures using openGL 935

D.W Seng, H.X Wang & G.Y Yue

Nonlinear displacement-time series intelligent model for tunnel based on PSO-BP 939

C Xu, B.G Liu & K.Y Liu

Computer simulation of structural failure under unexpected loads in rock engineering 943

J.X Xu & X.L Liu

Y Xu & Z.X Zhang

Prediction of PDC bit drilling force based on rock cutting mechanics theory 955

Y.X Yang, D.K Ma, B Li, M Lin, Y Liu, J Ma, H Zeng & X.L Fan

Study on safety and prevention of geologic environmental damage during the construction

X.G Zang, G.M Yu, A.H Wang, M.P Zhang & Y.Y Xu

Study on the application of slope risk assessment model by taking parameters’

L Zhang, X.X Wang & W.H Gu

Advances in KAISER effect of rock acoustic emission based on wavelet analysis 973

K Zhao, X.Y Zhi, X.J Wang, J.F Jin & G.F Wang

Model identification of geotechnical engineering based on genetic programming 977

T.B Zhao, J.Y Yao, Y.L Tan, Y.X Xiao & Z.G Zhao

XIV

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

Preface

John A Hudson FREng

Emeritus Professor,Imperial College, UKPresident,

International Society for Rock Mechanicsjohn.a.hudson@gmail.com

These Proceedings represent the papers accepted for the International Young Scholars’ Symposium on RockMechanics held in April 2008 in Beijing, China The Symposium was sponsored by the International Societyfor Rock Mechanics (ISRM) and the Chinese Society for Rock Mechanics and Engineering (CSRME)

To develop and improve any subject requires continuity—through young researchers advancing our knowledgebased on past information, and incorporating new techniques and new experiences Moreover, these advancesshould be achieved on all fronts, as is the case with the papers in this volume which are thematically arrangedwithin a wide spectrum of subjects: field investigation and instrumentation, rock properties and mechanicalbehaviour, underground mining and excavation engineering, rock slopes and landslides, tunnels and founda-tions, dynamics and blasting, and new techniques and methods It is, therefore, encouraging to observe thismanifestation of the talents of our Young Scholars via these∼200 papers on the many different rock mechanicstopics, and hence to anticipate further research breakthroughs

Having faith in the capabilities of this next generation, I am looking forward in the years ahead to the YoungScholars’ resolution of a major problem which relates to the application of rock mechanics knowledge in rockengineering On the one hand, we already have a great deal of rock mechanics knowledge but, on the other hand,

we are lacking in our ability to utilise this knowledge to fully support rock engineering design and construction.For example, we find it difficult to establish the in situ rock stress and its overall variation within a specific rockmass We still only use empirical rock failure criteria, usually employing just two of the three principal stresses

We are often unable to reliably specify the complete distribution of rock fractures in a rock mass, with a corollarybeing that discrete fracture network modelling for water flow is never easy And, although numerical modellinghas progressed in leaps and bounds in recent decades, we still do not know if such models actually representthe rock reality Furthermore, there is currently no internationally agreed auditing procedure to check either thevalidity of the rock mechanics supporting information or the rock engineering design itself Thus, there are stillmany research problems, theoretical and applied, awaiting Young Scholars’ attention, the solution of which willsignificantly help rock engineering

The main aim of the Symposium is to promote the exchange of ideas and experiences and to share recentadvances in rock mechanics and engineering among Young Scholars in the world The papers contained hereinand the associated presentations at the Symposium itself illustrate how this has indeed been achieved Hopefully,

an additional benefit of the meeting will be the stimulus and encouragement provided to the Young Scholars sothat they will tackle our outstanding rock mechanics and rock engineering problems with renewed vigour.All our thanks go to Professor Meifeng Cai, Chairman of the Organising Committee and President of theISRM Commission on Education, for arranging both an excellent suite of papers and an enjoyable Sympo-sium Additionally, our appreciation is extended to the Organising Committee Members, the authors and theparticipants for ensuring such a successful gathering

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

Organization

Prof B.H.G Brady (Australia) Prof M.F Cai (China)

Prof C Erichsen (Germany)

Prof J.A Franklin (Canada) Prof X.T Feng (China)

Prof N.F Grossmann (Portugal) Prof C.A Tang (China)

Prof D.S Gu (China)

Prof P.K Kaiser (Canada) Prof S.H Hao (China)

Prof M.A Kwasniewski (Poland) Prof R.Q Huang (China)

Prof N Vander Merwe (South Africa) Prof Z.K Li (China)

Prof J.-C Roegiers (USA) Prof X.X Miao (China)

Prof O Stephansson (Germany) Prof F Pellet (France)

Prof J Zhao (Switzerland) Prof Z.Q Yue (Hong Kong, China)

Prof R.W Zimmerman (Sweden) Prof G.J Zhang (China)

Prof B.X Zheng (China)

Prof M.W Xie

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

ACKNOWLEDGEMENTS

The International Young Scholars’ Symposium on Rock Mechanics 2008 has been organized by the ISRMCommission on Education and supported by the University of Science and Technology Beijing (USTB), ChinaUniversity of Mining and Technology (CUMT) and Chongqing University (CU), under the sponsorship of theInternational Society for Rock Mechanics (ISRM) and the Chinese Society of Rock Mechanics and Engineering(CSRME)

Sincere thanks go to Professor J.A Hudson, the ISRM President, for his support of the Symposium andkindness in writing the Preface of these Proceedings

The contributions made by the Members of the International Advisory Committee, the Members of theAcademic Committee and the Members of the Organizing Committee are greatly appreciated

Special acknowledgements go to Dr M Kwasniewski, Prof R.W Zimmerman, Dr J.P Harrison,Prof J.-C Roegiers, Prof Y.J Wang and Prof H.H Lai for their efforts in reviewing and revising the paperssubmitted to the Symposium

Financial support for the Symposium from Guangdong Hongda Blasting Engineering Co Ltd., SinosteelMining Co Ltd, Pingdingshan Coal (Group) Co Ltd., Mining Company of Capital Steel (Group) Co andITASCA Consulting Group Inc is also deeply appreciated

Professor Meifeng CaiChairman of the Organizing Committee

Field investigation and instrumentation

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

Stress field characteristics and prediction of rockburst in the tunnel area from Make river to Keke river in the west line of SNWDP

M.F Cai & X.O Xia

School of Civil and Environmental Engineering, University of Science and Technology, Beijing, China

H Peng & X.M Ma

Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, China

ABSTRACT: The main researching object of this paper is to obtain the distribution law of stress field in thedeep and long tunnel from Make river to Keke river in west line of the South-North Water Diversion Project(SNWDP) On the basis of field geological survey, in-situ stress measurement rock mechanics test and FEMnumerical simulation, the stress distribution law in the tunnel area is comprehensively analyzed and evaluated.The results of the analyses provide a scientific basis for design, construction and supporting of the tunnelexcavation

1 INTRODUCTION

Rockburst is an engineering geological problem which

is often encountered during excavating in deep-buried

and high-stressed underground works So it is a kind of

geological hazard induced by human excavation

activ-ity It often occurs in the hard, integrity and brittle rock

mass In such rock mass, the high elastic strain energy

is liable to be stored, which is the basic condition for

inducing rock burst (Hou 1986 & Ma 2006)

West line of the South-North Water Diversion

Project is a strategic project which diverts the upper

water of the Yangtze River in the southern China to the

lower Yellow River in the northern China to resolve

the critical problem of serious lack of water in

North-western region of China The tunnel from Make river

to Keke river diverts the water from Make river to

Keke river and, therefore, it is a key project to divert

water crossing the Bayan Kalatongke mountain The

length of the tunnel is 53 km, and the maximum buried

depth is 1200 m The main surrounding rock of the

tunnel is shallow-metamorphism sand and slate of

Triassic However, the brittle granites and granite

dior-ite of Mesozoic are developed in some local parts of

the tunnel, which provides a condition for storing high

energy At the same time, most parts of the tunnel

will cross high stress area Therefore, rockburst is

the most prominent geological disasters in the

tun-nel project from Make river to Keke river In this

paper, on the basis of engineering geological survey,

in-situ stress measurement, rock mechanics

experi-ment and 3-D FEM calculation, the stress distribution

state in the tunnel area is obtained (Peng 2004)

At last, the possibility of the rockburst is analyzedand discussed

2 GEOLOGICAL CONDITIONSThe deep-long tunnel from Make river to Keke river

is located between Aba County in Sichuan Provinceand Banma County in Qinghai Province, crossing theBayan Kalatongke mountain It is a key tunnel in thewest line of the South-North Water Diversion Project.Its direction is N35◦E and the averaged altitude is

3442 m The lithology of the tunnel rock is mainlyslate and sandstone, which suffered structural move-ments of folding, fracturing and shear sliding in severaltectonic periods

According to rebound analysis in site, the uniaxialcompressive strength of the weak weathered sandstone

is 41–28 MPa and that of the weak-breeze weatheredslate is 21–95 MPa The majority of slate is middle-hard rock and its other small portion is hard or softrock

The bearing stratum in the tunnel area is composed

of the hard layered sandstone with slate double layergroup, the harder thin-layered sandstone and slategroup, the harder thin-layered slate with sandstonedouble layer group The three kinds of rock groupsare formatted by mudstone, sandstone via the regionaldynamic metamorphism Folds, joints, beddings andfoliations are development in this region

The dry-anti value of the slightly weathered

meta-morphic slate is 8.2–11.1 MPa The dry-anti value

of metamorphic sandstone in the weathered belt is

2.4–102.7 MPa and is less than 80 MPa for more than

95 percent of this kind rock The dry-anti value of slate

is 3.0–76.3 MPa and is less than more 30 MPa for more

than 85 percent of this kind rock

The above introduction shows that the integrity of

rock mass in the area of the tunnel from Make river to

Keke river is quite poor

3 DISTRIBUTION LAW OF IN-SITU

STRESS STATE

Using hydraulic fracturing technique (ISRM 1987, Cai

2004), in situ stress measurement has been carried out

in the tunnel area from Make river to Keke river (Peng

2006 & Ma 2005) The measuring points are as close

as possible to the key parts of geological structures at

central, entrance and exit of the tunnel (Cai 2000)

Therefore, 4 measuring points were selected at the

Duke Dam site, Ya ertang dam site, Aba Bizu ranch

and Aba dam site The depth of the measuring

bore-holes was 200 m, 80 m, 30 m, and 151 m, respectively

In addition, hydraulic fracturing stress measurement

has also been completed by Design Institute of the

Yellow River Water Conservancy Commission at other

2 points (ZK14 and ZK15) with borehole depth of

445 m and 352 m, respectively The 6 measured points

are shown in Figure 1

The measuring results in 6 boreholes are shown in

Table 1 From the measuring results, the distribution

law of in situ stress state in the tunnel area is obtained

as follows (Cai 1993)

1 The horizontal principal stress is dominant in the

stress field of the tunnel project area The ratio of

maximum horizontal principal stress (σH) to the

vertical stress (σv) is 1.42 to 10.08 with an

aver-age value of 2.81 The value belongs to a moderate

level The magnitude of 3 principal stresses, i.e

σH,σh(minimum principal stress) andσvpresents

that order:σH> σh> σv

2 The orientation of maximum horizontal principal

stress is between NE20.0◦ and NE58.0◦ with an

average of NE46.6◦ It is consistent with

direc-tion of the modern tectonic stress field which is

NE-NEE

3 The stress state in the tunnel area reflects reversed

fault state In both sides of Bayan Kalatongke

mountain, the stress state is completely different

In North side of the mountain, the magnitude of

stress is relatively small with a direction of NN for

the maximum principal stress, but in the South side

of the mountain, the magnitude of stress is much

Figure 1 Layout of stress measuring points at the tunnel project area.

Table 1 In-situ stress measurements results in the tunnel area.

Magnitude of stress

hole ing point (m) σ H σ h σ v ofσH ( ◦)

larger than that in the north side with a direction of

NE for the maximum principal stress

4 Both the maximum and minimum horizontal cipals tresses are increased with depth According

prin-to the in-situ measuring data, linear regression

4

results ofσHandσhare as shown in Equations (1)

4 NUMERICAL ANALYSIS OF STRESS

AND ENERGY DISTRIBUTION

IN THE TUNNEL AREA

Using 3-D ANSYS FEM software, the stress

distri-bution in the rock mass surrounding the tunnel from

Make river to Keke river is analyzed From the

anal-ysis, possibility of rockburst during excavation of the

tunnel is also predicted The three-dimensional finite

element model is shown in Figure 2

From the numerical modeling, following

conclu-sions are obtained

1 There is remarkable stress concentration in the two

sides of the fault The maximum value ofσ1

(hor-izontal) in two sides of the fault is 81.0 MPa and

49.5 MPa, respectively, and the maximum value of

σ2(horizontal) in two sides of the fault is 46.1 MPa

and 24.3 MPa The values of stress is becoming

smaller as it is more distant away the fault The

value of stress is also decreased as it is across

the fault The maximum value ofσ3 (vertical) is

11.5 MPa which is no remarkable increase in the

two sides of the fault

2 Based on the calculated values of stress and strain

in each element, elastic strain energy stored in the

rock mass is obtained The value of the stored

elastic strain energy per unit volume of the rock

is varied along with the tunnel line, as shown in

Figure 3 In the Figure, two peak values appear

at places 24.0 km from entrance of the tunnel and

29.2 km from entrance of the tunnel with two peak

values of 8.50× 1010J/m3and 3.35× 1010J/m3

3 Based on the calculation results of stress

con-centration and stored elastic strain energy in the

surrounding rock mass along the tunnel line, the

tress environment for inducing rockburst is

eval-uated Based on laboratory experiment results of

mechanical properties of rock, the ability of rock

to store energy is obtained The main

surround-ing rock of the tunnel is shallow-metamorphic sand

and slate, brittle granites and granitic diorite, all of

which posses ability to store high energy

Accord-ing to the tress environment and rock mechanical

property conditions, using the rock burst judgment

criteria with indexes of elastic energy, brittleness of

Figure 2 3-D FEM analysis model.

Figure 3 Curve of stored elastic strain energy per unit volume of rock along the tunnel line.

the rock (the ratio of uniaxial compressive strength

to tensile strength), the ratio of maximum principalstress to uniaxial compressive strength and RQD ofthe rock mass, the possibility, magnitude and place

of rockburst induced by tunnel excavation are lyzed and predicted (N.B.T.S & M.C 1995, Shen &Guan 2000, Cai et al 2002, M.R 2002) Accord-ing to the prediction analysis, rockburst can beinduced in 77.3% of length of the tunnel The max-imum seismic intensity of the rockburst is VII Thedetailed prediction results of possibility to occurrockburst along tunnel length are as follows.16.0% of length of the tunnel: no rockburst;13.6% of length of the tunnel: no or slightrockburst;

ana-18.4% of length of the tunnel: slight to midiumrockburst;

45.3% of length of the tunnel: midium to strongrockburst;

6.7% of length of the tunnel: very strong burst

The above prediction shows big possibility for burst to be happened in some sections of the tunnel

To control occurrence and reduce intensity of the

rock-burst, a series of proper measures should be taken

during excavation of the tunnel

5 CONCLUSIONS

1 In situ stress measurement with hydraulic

fractur-ing technique has revealed the distribution law of in

situ stress state in the tunnel area from Make river to

Keke river Stress field in the area is dominated by

horizontal principal stress The ratio of maximum

horizontal principal stress (σH) to the vertical stress

(σv) is 1.42 to 10.08 with an average value of 2.81,

which indicates that the in situ stress in the area is

belong to high level

2 The orientation of maximum horizontal

princi-pal stress is between NE20.0◦ and NE58.0◦ with

an average of NE46.6◦, which is consistent with

direction of the modern tectonic stress field

3 The stress state in two sides of Bayan Kalatongke

mountain is completely different, which reflects

reversed fault state in the tunnel area

4 According to field investigation, laboratory

exper-iment and theoretical analysis of the stress

envi-ronment condition to induce rockburst and rock

property condition possessing ability to store high

energy, the rock burst with different degrees is

pos-sible to be induced by tunnel excavation in most

length of the tunnel

5 To ensure safety and stability of the tunnel, a series

of proper measures should be taken before,

dur-ing and after excavation to control occurrence and

reduce intensity of the rockburst

Therefore, the above analyses on stress distribution

law and prediction of rockburst have provided a

sci-entific basis for reasonable design, construction and

supporting of the tunnel

REFERENCES

Cai, M.F 1993 Commentary of principle and techniques

of rock stress measurement Chinese Journal of Rock

Mechanics and Engineering, Vol 12, No 3: 275–283

(In Chinese).

Cai, M.F 2000 Principles and techniques of in-situ stress

measurement Beijing: Science Press (In Chinese).

Cai, M.F., Wang J.A., Wang S.H 2002 Study on distribution law of in situ stress and prediction of rockburst in Ling-

long gold mine Chinese Journal of Rock Mechanics and Engineering, Vol 12, No 3: 275–283 (In Chinese).

Cai, M.F 2004 Rock stress and its in situ measurement In: Wang Sijing ed Century Achievement of Rock Mechan-

ics and Engineering in China HeHai University Press,

Nanjing, China, 485–515 (In Chinese).

Hou, F.L., Jia Y.R 1986 The relations between rockburst and surrounding rock stress in under-ground chamber In: Pro- ceedings of the Inter-national Symposium on Engineering

in Complex Rock Formations Science Press, Beijing,

China, 11: 497–505 (In English).

ISRM 1987 Suggested methods for rock stress

determina-tion Int J Rock Mech Min Sci Geomech Abstr Vol.

24, No 1: 55–73 (In English).

Ma, X.M., Peng, H., Li, J.S et al 2005 Application of hydraulic fracturing in situ stress measurements in tunnel-

ing in western Xinjiang Journal Geo-mechanics, Vol.11,

No 4: 386–393 (In Chinese with English abstract).

Ma, X.M., Peng, H., Li, J.S et al 2006 In situ stress surement and its application to rock burst analysis in Xin

mea-Baiyanzhai tunnel of the XIANGYU railway Acta scientia Sinica, Vol 27, No 2: 181–186 (In Chinese with

Geo-English abstract).

Ministry of Railway 2002 Railway tunnel construction

technical specifications Chinese Railway Press, Beijing,

China (In Chinese).

National Bureau of Technical Supervision, Ministry of Construction 1995 Project rock grading standards

(GB50218–94) China plans Press, Beijing, China (In

Chinese).

Peng, H., Cui, W., Ma, X.M et al 2006 Hydrofractur-ing

in situ stress measurements of the water diversion area in the first stage of the south-north water diversion project

(western line) Journal of Geomechanics, Vol 12, No 2:

182–190 (In Chinese with English abstract).

Peng, H., Ma, X.M., Ba, J.Q et al 2006 Characteristics of

quaternary activities of the Garze-Yushu fault zone nal geomechanics, Vol 12, No 3: 295–304 (In Chinese

Jour-with English abstract).

Peng, H., Ma, X.M., Li, J.S et al 2004 Investigation and assessment of stability of the first phase district in west

line of the South-North Water Diversion Project Research Institute of Geomechanics, CAGS, Beijing, China (In

Chinese).

Shen, Zh.Sh., Guan, B.S 2000 Railway tunnel rock

clas-sification Southwest Traffic University Press, Chengdu,

China (In Chinese).

6

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

Identification of geological interfaces from drilling process monitoring

in ground investigation

W Gao, J Chen & Z.Q Yue

Department of Civil Engineering, The University of Hong Kong, Hong Kong, China

ABSTRACT: The method of using a hydraulic rotary drilling machine to explore conditions of subsurface iswidely applied in ground investigation A new technique, Drilling Process Monitor (DPM) has been recentlydeveloped to automatically and continuously monitor the full drilling process From analyzing DPM data, thepure drilling curve versus time can be obtained The drilling rate as an index for characterizing the groundcondition can be calculated with confidence It is observed that the drilling rate is variable with depth and thevariation is consistent with the change of geomaterial properties along the drillhole depth Thus, the DPM dataare capable of determining the positions of geological interfaces A case study is given in the paper to illustratehow to find and locate the interfaces according to the DPM data Comparisons are also made between the DPManalyzed results and the recovered core samples

1 INTRODUCTION

Drilling, boring, rotary core samplings, and the

associ-ated logging can provide the basic ground information

for geotechnical design and construction Therefore,

drilling is one of the most commonly used methods

in ground investigation The concept of drilling

para-meter recording was introduced into civil and

min-ing industries in the 1970s (Peck & Vynne 1993)

It was originally applied in the oil, gas and mining

industries (Chugh 1992, Somerton 1959) It utilizes

the information collected through the drilling for the

purpose of ground characterization It is defined as a

technique to measure, to transmit and to record the

information (i.e drilling parameters) related to the

drilling (Kazuo 1998) Over the last three decades,

a number of researchers and engineers have

car-ried out research work on how to record and use

drilling parameters for ground characterization The

techniques include ENPASO (Hamelin J.P 1982, Gui

1999, 2002, 2004), MWD (Nishi, K, Suzuki &

Sasao 1998), ADM, and DPR (Benoit and Sadkowski

2004)

Despite the advantages in such drilling

para-meter recording and some successful cases for ground

characterization, however, the relevant techniques and

methods have not become a common or standard

ground investigation tool in the civil and mining

indus-tries (Yue 2004a) Drilling parameter recording (or

instrumented drilling) is still a comparatively new

con-cept in terms of regular implementation in

geotech-nical engineering (Gui 2002, Yue 2004a) Hydraulicrotary drilling rigs have not been equipped with adevice to monitor and record the full drilling process inreal-time The present manual recorded results leaveample room for variance and errors

It is, therefore, necessary to further develop situ devices and associated data analysis methods forautomatically monitoring the full drilling process ofdrilling machines and for accurately and effectivelyzoning soil and rock profiles An innovative in-situdevice, namely, the drilling process monitor (DPM)for automatic recording has been developed at HKU(Sugawawa 2002a, 2002b, 2002c, 2003, Tan 2005,Yue 2001, 2002, 2003, 2004a, 2004b, 2004c, Yue

in-2004, 2005, 2006) The DPM can be easily and destructively fitted onto any type of drilling machines

non-It can automatically, objectively and continuouslymeasure and record drilling parameters in real timewith a given time sampling rate It can record the fulldrilling process and operations that are experienced

by a drilling machine when it is drilling a hole inthe ground It has been found that the electronic datafrom the DPM can be used to zone and to characterizethe structural geometries of weathered rock and soilprofiles in depth

This paper will briefly describe the DPM techniquefor monitoring and recording the full drilling pro-cess associated with ordinary hydraulic rotary drillingmachines The actual DPM data will be presented toshow that a wealth of extra factual data can be obtainedfrom the real time monitoring of ordinary hydraulic

rotary drilling in ground investigation Interpretation

of the DPM data can be used to assess the variability

of geological strata along the drillhole depth

2 DRILLING PROCESS MONITORING

Drilling a hole for subsurface exploration using a

hydraulic rotary drilling machine is one of the most

common methods in geotechnical engineering Soil

or rock samples were usually retrieved for laboratory

tests Different types and sizes of drill bits, casings can

be selected by operators in terms of in-situ techniques

and practical layer properties At least two workers are

needed to operate the machine

Based on the design and operation of the hydraulic

drilling machine in ground investigation, the drilling

process monitor (DPM) has been developed to monitor

the associate drilling parameters to represent the full

drilling process in real-time sequence and in a digital

manner, as shown in Figure 1

DPM are designed for the installation onto the

drilling machine All of the sensors are required to

integrate together with the drilling machine

harmo-niously so that normal operations will not be disturbed

during drilling A portable computer or a LCD display

is used to show the variation of each parameter while

the drilling is continuing in real time Raw data are

saved as a digital file for later analysis

Several dominant drilling parameters are to be

monitored They are as follows:

1 Downward or upward movement of the swivel drill

head along the two vertical drill spindles;

2 The forward and reverse rotation of the drill rod;

3 The downward hydraulic pressure for moving the

swivel drill head downward;

4 The upward hydraulic pressure for moving the

swivel drill head upward

Figure 1 Drilling process monitoring system.

3 CASE STUDY

A site investigation was carried out to evaluate thegeological condition and potential disaster at a site

in Shen Zhen As part of the project, drillholes were

Figure 2 Relative location of the four drillholes.

Figure 3 Real-time series of the chuck position (a), rotation per minute (b), downward pressure (c) and upward pressure (d) during drilling the hole ZK2.

8

used to explore the detailed geological condition of

underground strata in this area The drilling was

car-ried out with an ordinary hydraulic drilling machine

As shown in Figure 2, the drilling site was in front of

a hillside slope A river was just nearby Four drillholes

(i.e., Nos ZK1, ZK2, ZK3 and ZK4) were carried out

and their drilling processes were monitored with DPM

3.1 DPM Data

In this paper, the original DPM data for the drilling of

the drillhole No ZK2 is used as an example to illustrate

the methodology of analysis and interpretation

Figure 3 shows the factual data monitored with

DPM for the drilling process from the time 14:30:00

to the time 19:00:00 The data show the movement of

chuck head, the rotation speed, the downward pressure

and the upward pressure in time series, respectively

3.2 Data differentiation

As shown in Figure 3, the full drilling process, actually,

is a combination of a series of individual and different

operations in real-time sequence To derive the pure

drilling curve versus time, the following criteria shall

be satisfied at any time point t i:

1 The chuck position keeps moving downward, i.e.,

C p (t i+1) ≤ C p (t i );

2 Rotational direction is clockwise;

3 Rotation speed is greater than zero, i.e.,

RPM (t i ) >> 0;

4 Downward pressure is greater than upward

pres-sure, i.e., D p (t i ) ≥ U p (t i )

With the above criteria, the original DPM data are

to be sorted Each of pure drilling segments can be

obtained accordingly The pure drilling curve can only

be produced by the accumulation of each of these

seg-ments in time sequence A data analysis software has

been developed to efficiently and accurately process

and analyze the original DPM data The data

pro-cess and analysis can be quickly done and the relevant

figures and results can be outputted automatically

3.3 Data analysis

In the analysis, as shown in Figure 4, the slope of

the curve for the drilling advancement versus pure

drilling time is defined as the drilling rate (DR) It

may vary as the depth increases In fact, this slope

value shows the speed of the drilling bit advance at

different given geomaterials It is understood that the

machine performance is influenced by both the

geo-material mechanical properties and drilling machine

quality However, the change in the curve slope value

(or the drilling rate) can be attributed to the change in

geomaterials along the drillhole, under the condition

of a single drill machine and drill bit being usedduring the drilling of that drillhole Therfore, thestronger the geomaterial is, the lower the DR value

is, and vice versa The high DR value indicates a weakgeomaterials encountered during the drilling

In order to clearly demonstrate the change ofdrilling rate along a drillhole, the drilling rate valuecorresponding to each constant slope along the bitadvancement versus the pure drilling time curve iscalculated, plotted and interpreted in Figure 4 Com-parison was also made between the DPM zoningresults, drilling rate variation, and the manual loggingprofile along the drillhole No ZK2

From the bit-advancement versus pure drilling timecurve, an essential assessment can be made on thevariability of geological strata in ZK2 The entire curvecan be divided into three main segments according tothe curve slope variations:

a from ground (0 m) to the depth 7.5660 m

b from the depth 7.5660 m to the depth 25.9014 m,

c from the 25.9014 m to the depth 30.0612 m

Figure 4 The bit-advancement versus pure drilling time curve.

The results indicate that three types of

geomateri-als were encountered during the drilling The interface

depths where the geomaterial had changed are at

7.5660, 25.9014 and 30.0612 m below the ground

From the ground surface to the depth 7.5660 m, the

minimum drilling rate is 0.4351 m/min The average

drilling rate is 0.6982 m/min

Below the depth of 7.5660 m, the drilling rate has

an abrupt big reduction from the large value of 0.6453

m/min to a small value of 0.0462 m/min According

to the manual logging, there was a change in the strata

from sand soil to slightly decomposed marble at the

depth of 7.5 m The abrupt reduction shows the

geo-logical interface between the upper soil layer and the

lower marble

From the depth 7.5660 m to the depth 25.9014 m,

the drilling rate almost keeps at a constant level It is

less than 0.05 m/min The average drilling rate is equal

to 0.0396 m/min, which indicates the geomaterials was

Figure 5 The DPM zoning results (a), drilling rate

varia-tion (b), and the manual logging profile (c), along the drillhole

DR: 0.0351m/min

25.9

30.1

Gray, integrated,slightly decomposed marble

Cavity

Gray, slightly decomposed marble

Figure 6 The comparison between the DPM zone and the

manual logged zone of the cavity, and with evidence of a site

photograph of cores in ZK2.

hard to be drilled During this depth zone, the cores

of slightly decomposed marble were continuouslyrecovered The upper and lower depths measuredfrom the manual logging were 7.5 m and 25.9 m,respectively

Below the depth of 25.9014 m, the drilling ratesuddenly jumped to a much large value It is 1.3455m/min A cavity was found there and no samples wereobtained from the drilling The cavity extended tothe depth of 30.0612 m where marble was encoun-tered again The thickness of the cavity is 4.1598 m.Figure 6 further shows a photograph of missing coresduring cavity zone (25.9 m∼30.1 m), and a compari-son between the DPM and manual logged boundariesfor the top and bottom depths of the cavity zone.Below the cavity, the drilling rate dropped back to0.0351 m/min

4 FURTHER RESULTSComparisons were made for the main geological inter-face detections between the DPM monitored depthsand the manually logged depths for the drillhole Nos.ZK1, ZK2, ZK3, and ZK4 at the site The results aregiven in Table 1

The average drilling rate in soil strata and marble,

as well as ratio of their DR values for each hole werealso calculated in Table 2

Table 1 The variation of drilling rate before and after the main interfaces.

Interface Relative difference depth from Interface between DPM monitored manual depth from and manually logged logging DPM interface depth Hole

The above DPM data and results can show:

• From the large change in the drilling rate, it is easy

to find the accurate depth of critical geological

inter-face between soil strata and rock (marble) The final

results have been compared with the site manual

logging report Table 1 shows that the relative

dif-ferences between the depths from the two methods

are less than 1.5%

• The comparison in Table 2 shows the average

drilling rate values in soil and marble respectively

It is clear that drilling in soil strata has much higher

speed than that in marble The average value of

drilling rate in soil strata is more than 18 times

higher that in marble Besides, it is observed that

the lowest drilling rate in soil strata is still 8 times

higher than the highest drilling rate in marble The

large difference is helpful to judge whether or not

the natural ground characteristics have substantial

changes The similar drilling rate along a drillhole

can be grouped into suitable geological strata zones,

accordingly

• Based on the results in the drillhole No ZK2, some

variation range of the drilling rate can be

summa-rized for the different types of the geomaterials

along the drillhole at the site with the used drilling

c For cavity without infilling, the drilling rate is

greater than 1.3 m/min

• Two geological interfaces in the top soil layer are

detected with DPM However, since the upper soil

samples were recovered a few percentages, the soil

formation could not be described by the manual

logging Detailed comparisons can not be made

between the DPM results and the manual logging

samples In addition, the actual drilling

perfor-mance in the soil strata can be further examined by

comparing the DPM results with the manual

log-ging results if the soil samples can be completely

recovered

5 CONCLUSIONS

The DPM results, in particular, the bit advancement

versus the pure drilling time curve can provide

valu-able factual information for better understanding the

actual drilling Based on the curve, it is easy to make

an assessment on the variability of ground geological

strata along the drillhole depth The depths of the

crit-ical geologcrit-ical interfaces can be detected accurately

The variation ranges of the drilling rates ing to three different types of geomaterials at the casestudy site are defined for the used drilling machine

correspond-In particular, the cavity below the ground can beidentified from the DPM data accurately

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12

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

Surface movement monitoring and analysis based on GIS

C.L Li

Earthquake Engineering Research Center, China Institute of Water Resources and Hydropower Research,

Beijing, China

X.L Li

Civil and Environment Engineering School, University of Science and Technology, Beijing, China

ABSTRACT: It takes the Beiminghe iron mine as the research background and a ground movement monitoringsystem has been built to guide the safety production GIS is applied to improve the efficiency and visualizationdegree of monitoring data By using data query, the effective spatial analytical function and the drawing tools ofGIS, the degree and scope of ground movement are intuitively shown The system has made the good result inthe practical monitoring of ground movement, and can provide the scientific basis for guiding safety production

of the mine

1 GENERAL INSTRUCTIONS

The exploitation of mine resources underground can

satisfy the developing needs of civil economy, but as

the same time, it also can bring geological disasters,

such as ground movement (He 1994, Huang 2003)

Ground movement can lead plantation destroyed,

building damaged, ground environment changed, and

constitute a threat to the safety of the industry and

agriculture production

Ground movement by mining is a complicated

process affected by many factors, such as geology

condition, hydrology environment, mining method

etc So setting observation stations in locale is the

most reliable way to predict dangers caused by ground

movement

Traditional observation data usually record with

CAD drawing or chart, as the result, the spatial

characteristics and the development trend of ground

movement can not be shown visually, and the efficient

of index and analysis of the observation data is very

low (Chai 2004)

Geographic Information System (GIS) is a new

sub-ject developed in recent years, which mixed with many

subjects, such as computer, geography, information,

environment science etc GIS has strong function, such

as data collection, date index, model building,

spa-tial and attribute data processing, spaspa-tial analysis etc

(MILLER 2003, Liu 2005, Duane 2000, LI 2001)

GIS has perfect expressive force of space and can offer

multi-information of space and dynamic environment,

so GIS is a good soft plot to study on how to monitorground movement efficiently and intuitively

So this paper apply GIS into ground movementmonitoring to improve the efficiency of data pro-cessing, and a monitoring system is built based onGIS to provide the scientific basis for guiding safetyproduction of the mine

The Beiminghe Iron Mine is located in Shangtuanvillage, Wuan town, Hebei province It’s area reach

2000 m, geographic coordinate is: east longitude

114◦730, north latitude 36◦450 Geological

re-serves are 79 million tons Plan output one year is1.8 million tons Beiminghe Iron Mine is designed toserve 35 years by Caving method

By many years exploitation, the ground of theBeiminghe Iron Mine moves intensely Two subsi-dence pits has been formed in the ground near measurewell at end of February 2003 (Ouyang 2005) Thediameter of the bigger one is about 15 m (Figure 1),and the measure well has to be abandoned There aremany cracks on the ground near the subsidence pits,and the maximal width of the cracks reaches 400 mm(Figure 2) In order to avoiding the tragedy, we mustset up the efficient observing system to monitor theground movement

Figure 1 Subsidence pit in the ground.

Figure 2 Cracks in the ground.

In order to monitoring ground movement,

observa-tion staobserva-tion must be set up on the ground before

exploitation The observation station means that many

interknitting observation points are set according to

some requires on the ground

There are two types of observation stations: net

observation station and section observation station

According to the fact of the Beiminghe Iron Mine, the

net observation station is set up on the ground affected

by caving In order to master the rule of the ground

movement, the observation points should be observed

to get its spatial position

3.1 Disposal principle of the observation station

1 Observation lines should be set on the main section

of the subsidence basin

2 The observation zone should not be affected by

other exploitation during the observation time

3 The length of observation lines must be longer thanthe half diameter of the subsidence basin

4 There should have enough points on the observationlines

5 The reference points of the observation stationshould be set outside the subsidence basin

3.2 Disposal form of observation points

The disposal form of observation points is very tant In order to getting the ground movement dataaccurately, the net form is chose as the disposal form

impor-of observation station The space between observationpoints is 100× 100 m The region outside subsidencezone 200 m is considered as the emphasis we shouldmonitor, and the space between observation pointshere is 50× 50 m

3.3 Standard of observation points and embedding demands

1 Piles of observation points should be prefabricated

in the factory The shape of the concrete frusta

is half pyramid with the upside smaller than theunderside, and a screw steel with diameter16 is

embedded on the center of each upside flat with

1∼2 cm left outside the top flat in order to protectthe observation points from destroying by people.The top of the crew steel should have the shape of

45◦angle inversed and be burnished.

2 The places of observation points should be fixed

on by the total-station instrument The suitablepits should be dug at the observation points with800∼1200 mm depth, and the underside of pitsmust be 500 mm deep under the frozen earth toavoid the cycle effect of freeze and expand If thesoil here is loose, the depth of pits must be deeper

to make sure that the underside of pits lies on thehard soil

3 Concrete should be put on the bottle of the pits,then put prefabricated piles in the pits, and someconcrete should be put into the pits subsequently.The pits will be filled and leveled up with surfacesoil when the concrete reach the demand standardafter conserved term

3.4 Measure instrument

All station informatics theodolite of Sokkia Set22dmade by Sony-Elision Corporation is chose as themeasure instrument for ground movement and itsmeasurement precision is±(2 + 2 ppm × D) mm.

14

3D coordinates of observation points can be got easily,

and based on them ground movement parameter can be

calculated, such as subsidence, horizontal movement,

slope, curvature etc

4 GROUND MONITORING SYSTEM

BASED ON GIS

4.1 Collect of source data

1 In order to ascertain the relationship between

ground environments and stope underground, some

data of the diggings should be collected, such

as exploitation scheme, ground ichnography, and

altitude drawings

2 Geology and hydrology data of the diggings, such

as geology drawings, preserved condition of the

mine, physical mechanic property of the cladding

rock and hydrological environment etc

3 Design data of stope, such as laneway

arrange-ment, caving method, management method of

roof, caving thickness, the push speed of working

face etc

4 Disposal drawing of observation station,

includ-ing: control points, lead points, coordinate

of observation points, and periodic observation

data etc

4.2 Building monitoring system of the Beiminghe

Iron Mine based on GIS

Monitoring system based on GIS expresses

geogra-phy objects and their relationship by digital form

The real world is described by a series of points,

lines and surfaces Geometry and topology

relation-ship of the geography data are put in the files, and

the altitude data are stored in the data management

system

All information in GIS is fixed by its coordinate

under special coordinate system, and its space data

and attribute data are stored and managed uniformly

The data model based on GIS has the base function of

inquiring and searching for data and figure, and can

offer the integrative analysis results

The figure data of the diggings are draw by CAD, so

the figure should be transformed in order to adapt the

software environment of GIS The transformed figure

data need to be preprocessed, including: correcting

mistakes, building right topology relationship, setting

up the attribute tables etc

Monitoring system based on GIS is built after all

diggings data have been transformed into numerical

format, such as figure 3 shown

observati Beiminghe stope buildings road river river bank subsidenc

road

Concentration plant

observation points crushing and dressing plant

concentration plant Beiminghe river

Tuancheng iron mine stop

Figure 3 Monitoring model based on GIS.

Figure 4 Attribute table of observation points.

From figure 1, the relationship between stopeunderground and the observation points on the groundcan be seen clearly in the monitoring system based onGIS

4.3 Date querying and analyzing

During the term from July to November in 2004, threetimes observation data has been mastered by using theelectron speed measure instrument Observation data

the querying point

Figure 5 Attributes of observation points.

Figure 6 Ground subsidence calculating.

are input into the ground monitoring system and saved

in the attribute table of observation points, such as

figure 4 shown

The query of figure data and its attributes can

be realized easily using the power functions of GIS

For example, querying the coordinates of observation

points (Figure 5) and observation data etc

Subsidence value of observation points can be

cal-culated with altitudes in different observation terms,

such as figure 6 shown

Ground subsidence from July to September and

from July to November has been analyzed using

N

subsidence nephograms

600 - 747 stope

river crushing and dressing plant

e

river crushing and dressing plant

Figure 8 Ground subsidence form July to November.

space analysis function of GIS, and the equivalencenephograms of subsidence are got (Figure 7, 8).From figure 6 and figure 7 we can see that observa-tion data and the result of analysis can be shown clearly

in the monitoring system of GIS Ground subsidenceoccurred in the south-west of the diggings from July

to November The range of subsidence was 360 m×

250 m from July to September, and the maximum ofthe subsidence was 0.487 m The range of subsidencereached 440 m× 400 m at the end of November, andthe maximum of the subsidence reached 0.747 m

According to the fact of the Beiminghe Iron Mine, anobservation station of net style is set up In order toimprove the efficiency of data analyzing, the groundmonitoring system based on GIS is built Using the

16

power function of GIS, such as data query, space

analyzing and figure showing, the efficiency and

visu-alization of data processing are improved The system

has made the good result in the practical monitoring

of ground movement, and can provide the scientific

basis for guiding safety production of the mine

REFERENCES

Chai, H.B., Zou, Y.F & Liu, J Y 2004 Application of DTM

in visualization prediction of mining subsidence

Jour-nal of Liaoning Technical University, 23(2): 171–174 (in

chinese).

Duane, F Marble 2000 Some thoughts on the integration

of spatial analysis and Geographic Information Systems.

Journal of Geographical System, (2): 31–35.

He, G.Q & Yang, L et al 1994 Technology of mining

subsidence China university of mining & technology

publishing compay, Xuzhou.

Huang, L.T 2003 Research and development of mining

sub-sidence mechanism Coal Science and Technology, 31(2):

Miller, H.J & Wentz, E.A 2003 Representation and spatial

analysis in geographic information systems Annals of the Association of American Geographers, 93(3): 574–594.

Ouyang, Z.H., Cai, M.F & Li, C.H et al 2005 Study on the Mechanism of Ground Collapse in Beiminghe Iron

Mine Mining Research and Development, 25(1): 21–23.

(in chinese).

Boundaries of Rock Mechanics – Cai & Wang (eds)

© 2008 Taylor & Francis Group, London, ISBN 978-0-415-46934-0

In situ stress state in engineering area of Dali-Lijiang railway

and its impact on the railway project

X.M Ma, H Peng & J.S Li

Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, China

ABSTRACT: Through field measurement, in situ stress state in engineering area of Dali-Lijiang railwaywas determined, including the magnitude and direction of in situ stress According to stress distribution law,mechanical parameters of the tunnel rock, rock engineering geological characteristics and other factors, the basiccharacteristics of the stress state at engineering area was obtained Furthermore, the possibility of rock burst andgeological disasters were analyzed during excavation of the tunnel It has provided a solid basis for supportingdesign, section choice and axis orientation determining of the tunnels

1 INTRODUCTION

Dali-Lijiang Railway with a total length of 164 km is

located in the northwest of Yunnan Province It is a

part of the Yunnan-Tibet railway line There are 47

bridges and tunnels along the Dali-Lijiang railway

line The Songshuyuan tunnel and Bijiashan tunnel are

located in the east of the Erhai Lake within Dali region

They are 5267 m and 3850 m long, respectively, with

a maximum burying depth of 300 m Thus, it is a key

engineering of Dali-Lijiang railway line Because new

tectonic movement is very strong at the Northwestern

region of Yunnan province, many adverse geological

disasters are very prominent along the line, such as

fault movements, landslides, rock collapse, mud-rock

flows, etc To the end, in situ stress measurement was

made at the tunnel engineering area along the

Dali-Lijiang railway line Hydraulic fracturing technique

was used for the measurement

Through the in situ stress measurement in two

boreholes (DZ-S-1, DZ-B-1), the present stress state

in rock mass surrounding the tunnel was identified

including the magnitude and direction of the in situ

stress According to in situ stress state, mechanical

parameters of the tunnel rock, rock engineering

geo-logical characteristics and other factors, the stress

distribution in the railway tunnel engineering area

is simulated and analyzed by making use of

three-dimensional finite element method Basic

character-istics of the stress distribution at engineering area are

obtained Furthermore, the possibility of rock burst

and geological disasters were analyzed during

exca-vation of the tunnel The analysis results provided a

solid basis for proper design of the tunnel, including

supporting design, section choice and axis orientationdetermining

2 GEOLOGICAL CONDITIONS

AT PROJECT AREAThe tunnel engineering area is located in north-west mountain of Yunnan hinterland in the Yunnan-Guizhou Plateau, belonging middle and southernmountainous areas of the Hengduan Mountains West-ern area is lower than Eastern, but Northern area ishigher than Southern Mountains and water systemappear on the South-North distribution It belongs toKarst, erosion tectonic geomorphology District ele-vation is about 1800–2786 m with relative elevationdifference up to 470–700 m The tectonic structures

in the area is very complicated, such as multi-leveldetachment and shear of the crust, sliding of settlingcover, folds and thrust of the sedimentary cover aredeveloped At the same time, there are two majornorth-south tension fractures in Dali developed due totheir mutual cross cutting (Peng 2004 & Peng 2006).Modern seismic activity is very active at engineer-ing area because of being located at the intersection ofthree seismic zones which include northwest, north-east and south-north seismic zones at Dali area Thelevel strike-slip is the basic feature of tectonic activ-ity of the earthquake The NW and NE faults aremostly developed at engineering area owing to beingaffected by active faults zone of the Red River and theYongsheng movement

Strata lithology is complex and changeable at theengineering area because sedimentary, metamorphic