Research on determination of optimal distance between two unsupported tunnels when consideration to shape changes

VIETROCK 2015 - an ISRM SPECIALIZED CONFERENCE 2015 VIETROCK 2015 International Symposium March 12-13,2015 Hanoi, VietNam ' ai- ‘ ** A_Jt J V ietn am ese) / y N ation al G r g t u g o f M ISR •/r,» Mi'?: ■*~v R o c k MECHANICS * » r ‘ VijJjl * * I j, for SUSTAINABLE DEVELOPMENT PUBI ISHING HOUSI I OR SCII NCI S AND II ( HNOI OGY HANOI, VIE! NAM, 2015 Vietrock2015 an ISRM specialized conference Vietrock2015 12-13March 2015, Hanoi, Vietnam Page Table of contents Committees XI ••• Preface X lll Acknowledgment XV Keynote papers Rock Displacement Monitoring using Satellite Technologies GPS and InSAR Norikazu Shimizu Understanding and utilizing in-situ rock stresses in design and building of underground caverns and tunnels 21 Eivind Gray, Ming Lu Some New Insights o f Rock Failure under Dynamic Loading 37 J Zhao, Q.B Zhang Experimental and Numerical Anisotropic Rock Mechanics 45 Ki-Bok Min, Hanna Kim and Bona Park In-situ rock stress and tunnel stability 56 Minh Lu, Nga P Nguyen Analysis on geological condition of rock mass with Hoek-Brown strength criterion 66 Qi Zhang, XianbinHuang, HehuaZhu, LianyangZhang Rock properties and testing methods 75 Definition of Rock Mass Properties by In Situ tests 77 MOSHE LEVIN Geomechanical properties determination based on data obtained from in-seam boreholes logging 86 Leonid A Rybalkin, Anton V Azarov, Andrey V Patutin, Tatyana V Shilova,Sergey V Serdyukov Estimation of Fracture Toughness of Sandstone by Three Testing Methods 92 Minami Kataoka,Shingo Yoshioka, Sang-Ho Cho,Kamil Soucek,Leona Vavro, Yuzo Obara Upgrading the rock mechanics laboratory at the Nanyang Technological University, Singapore Louis N.Y Wong 98 Vietrock2015 Vietrock2015 an ISRM specialized conference 12-13March 2015, Hanoi, Vietnam Consolidation of Crushed Salt backfill for Salt and Potash Mines 105 S Khamrat, S Somtong, K Fuenkajorn Effects of Stress Path on Polyaxial Strengths of Maha Sarakham Salt 112 K Artkhonghan, K Fuenkajorn Experimental Assessment of Mechanical and Hydraulic Performance of Cement Sealing in Rock Salt 122 S Pattani, P Tepnarong Shear Strength Testing under Constant Normal Load and Constant Normal Stiffness as Affected by Displacement Rates 131 P.Meemun, K Fuenkajorn Strengths o f Rock Fractures as Affected by Shear Velocities and Confinements 139 Kleepmek M , Fuenkajorn K Determination of the shear strength parameter of some rock types modeled by transversal anisotropic body 149 Pham Quoc Tuan, Nghiem Huu Hanh, Xia-Ting Feng Identify Driving Force to Cause Rockmass Destruction from Fracture Distributions 161 Thanh Truong Phi, Phi Quoc Nguyen Some opinions about TCVN 7572-10:2006 “ Method fordetermination of strength and softening coefficient of the original stone” 168 Nguyen Sy Ngoc Rock properties - numerical simulations 173 Multiple Yield Model in Anisotropic Rock for Underground Cavern 175 Takayuki MORI, Pham Quoc Tuan, Seiji MORIKA WA, Kazuto TABEI Some Research Activities on Rock Mechanics/Engineering at Nanyang Technological University, Singapore 187 Z Y Zhao, Y.X Zhou, W Nie Analysis on horizontal bearing capacity based on catastrophe theory of anti­ slide micropiles 196 Yiming Xiang, Wanxue Long, Hai Shi Automatic Rock Mass Discontinuities Detection Based on Binocular 3-D Reconstruction 203 J.Q Chen, H.H.Zhu, X.J Li Construction mechanical characteristics of shallow buried large span tunnel LI Yayong, JIN Xiaoguang, LVZhitao, DA Qingdong 212 Vietrock2015 an ISRM specialized conference Vietrock2015 12-13March 2015, Hanoi, Vietnam Investigation of Failure Mechanism and Process on Excavation Disturbed Zone (EDZ) of Underground engineering in Rock 221 DinhPhuc Hoang, GuangLi Xu, ZhiPeng Li, JiaXing Dong The oretical analysis o f deformation above roadways excavated in thincoal seam and rock stratification 230 DAO Viet Doan Geohazard (Landslide and Debris Flows)- Rock slope stability 241 Delineate Structural Boundary from Fracture Correlation Coefficients 243 Thanh Truong Phi, Gi Sang Hwang, Phi Quoc Nguyen Landslide susceptibility zonation - A comparison of natural and cut slopes using statistical models 252 QuocPhi Nguyen, TruongThanh Phi, AnhNguyet Nguyen, VanAnh Lam Formation and development of debris flows in Vietnam 259 Tran Van Tu, Dao Minh Due, Nguyen Manh Tung, Van Duy Cong The development excavation in Vietnam underground coal mine for period 2014 - 2020: the existing state and the solutions 273 Le Van Cong, Luu Cong Nam Large-scale field tests with flexible slope stabilization systems 280 Pham Quang Minh, Dennis Gross, Christophe Balg Application of photogrammetry in measuring geologic structures and creating a 3D model on exposed rock faces 289 Trung Thanh Dang The damage of the penstock of xekaman hydro power plant by sliding and its remedial measure for power generation 296 Bui Khoi Hung, Dao Manh Tung Method of geometry analysis for calculating rock slope stability to deal with wedge sliding 308 Tran Quoc Thinh, Nghiem Huu Hanh Analysis stability rock slope at left bank of South portal of North tunnel - Da Nang - Quang Ngai expressway 314 Pham Quoc Tuan, Phi Hong Thinh, Nghiem Huu Hanh Foundation of choosing projects for defending and reinforcing slopes side massif of loose rocks, but are combinated by clayey materials Do Thuy Dang 322 Vietrock2015 Vietrock2015 an ISRM specialized conference 12-13March 2015, Hanoi, Vietnam Development in Underground Hydrocarbon Storage 333 The Status of Underground Petroleum Stockpiling Businesses and the New Construction Project in Korea 335 Se-Joong Oh Underground Storage Project underneath an Artificial Island 336 Seokwon Jeon, and Chung-In Lee Rock Mechanics for the stability of underground oil and gas storage caverns Mechanical and hydrological aspect 342 Chung-In Lee, Seokxvon Jeon, Jae-Joon Songa, and Youn-Kyou Lee Safety Monitoring of Underground Oil Storage Facilities using AE and MS Technique 349 Eui-Seob Park, Dae-Sung Cheon, Yong-Bok Jung Compressed air energy storage in a lined rock cavern 350 Won Kyung Song Construction Case of Underground Storage Cavern In India 351 Jaewon Ryu Lessons on the Hydrodynamic Containment Design and Construction o f Oil Storage Cavern 352 Song Myung Kyu In-situ Volume Change Monitoring for Deep Underlay Strata with Fiber Optical Technology 358 Tatsuo Kokubo,Kazuyoshi Takenobu,Ikeda,Shoji Kunisue,Keiichi Ooba Tunnel and underground construction 365 Rock engineering service for unlined hydropower tunnels in Vietnam 367 N.Q Trinh, K.H Hoimay, E Grov Application of Continuous Maintenance Method for Aging Underground Powerhouse 376 Masayuki Kashiwayanagi, Norikazu Shimizu Blasting in a Rail Protection Zone in Singapore 384 Filippos I Manolas, Thamil Arusu Analysis of microtunnelling using process simulation module 394 Trung Thanh Dang Research on determination o f optimal distance between two unsupported tunnels when consideration to shape changes Tran Tuan Minh, Nguyen Duyen Phong 401 Vietrock2015 an ISRM specialized conference Vietrock2015 12-13March 2015, Hanoi, Vietnam Weak points must have been reformed in designing communication tunnels of Vietnam 410 Do Thuy Dang Rock foundation and Rock dynamics 425 Fundamental Study o f Effect of Waste Rock Condition on Control o f Acid Mine Drainage at Open Pit Coal Mine in Tropical Regions 427 Hideki Shimada, Takashi Sasaoka,SugengWahyudi, KikuoMatsui,Ginting J Kusuma,RudyS Gautama Geotechnical Issues on Application of Highwall Mining System in Indonesia 435 T Sasaoka,H Shimada, A Hamanaka, B Sulistianto, M Ichinose, K Matsui The Effectiveness assessment of On-Site Visualization and the application of various type of OSV on Hanoi Metro Line 445 C Izumi, S Akutagawa, M Nomura, H Zhang In-Situ Rock Testing for the Design of the Lai Chau RCC Dam 455 R.J Longden, Viet Ha Nguyen Study on High Pressure Impact Extrusionof the Foundation Curtain Deflection Core Fracture Zone o f the Sluicing Dam Section 465 Liu pan, Fan kai The use of the exponential function to predict surface subsidence due to underground mining 473 Quoc Long NGUYEN, KhacLuyenBUI Some solution handle swelling foundation when construction miningunderground in conditions Quang Ninh geology 479 Pham Minh Due, Tran Van Phu, Nguyen Thanh Ha Building a subsidence prediction module and applying for Nam Deo Naiwaste dump 490 BUIXuan Nam, NGUYEN Quoc Long Determining subsidence of soil layers in the process of building soilembankment 495 Viet Ha NGUYEN Author index 501 Vietrock2015 an ISRM specialized conference Vietrock2015 12-13 March 2015, Hanoi, Vietnam Research on determination of optimal distance between two unsupported tunnels when consideration to shape changes Tran Tuan M inha\ Nguyen Duyen Phongb Ha Noi University o f Mining and Geology bMoscow state mining university *Corresponding author’s email: tuanminhhumg(a),vahoo.com Abstract Determination distance between two transport tunnels is very important problem and has influence on the stability calculation and tunnel designations However, nowadays in Viet Nam this problem has many disadvantages This paper introduces the studying on determination of optimal distance between two transport tunnels when consideration to shape changes base on numerical method in Viet Nam’s geological conditions Introduction Vietnam is one of the most beautiful VIETNAM CHINA countries located in the South East Asia (figure 1) In the North, Vietnam shares the MYANMAR D long borderline with China In the East, G&Phu Vietnam is bordered by the Gulf of Tonkin, in the East and South by the South China Sea, in the South West by the Gulf of Thailand, and in the West by Cambodia and Laos Owning to stretching the length THAILAND of the Indochinese Peninsula, Vietnam VIETNAM boasts a unique shape of an elongated S and a long coastline of 3,260 km with a lot of wonderful sites Although Vietnam lies entirely within the tropics, the Vietnam’s climate surprisingly varies from region to Chi Minh O ty 1kmimd region with the annual average temperature from 22°C to 27°C because of its topography The mountainous people of Fig.l Location of Viet Nam Sapa in the north might be seeking shelter from snow while the urban dwellers of Ho Chi Minh City in the south seek refuge from mid-day heat Although it is a small country with the area of 329,560km2, there are up to 54 different ethnic groups inhabiting in Vietnam, of which Kinh (Viet) people accounts for nearly 86% of the whole population, and the others are ethnic minority groups that represent about 14% To develop industry in Viet Nam in the future we need building many hydroelectric power plants, thermal power plants, atom power plants and other energies to develop country, which can be listed as following: Hoa Binh Hydropower plant (figure 2a) was built from 1979 to 1994 with machines provides 1920MW- 1/3 productivity of Vietnam It is not only an important industrial construction but also an attractive sightseeing for visitors Many valuable items such as: Ho Chi Minh statue on Tuong hill with 18m height, the traditional area keeping letters, memorial Vietnamese and Soviet experts sacrifice to built hydropower projects Along with the functions of social, economic, Hoa Binh hydroelectric becomes an exciting destination for visitors The Son La Hydropower Plant (figure 2b) with a designed capacity of 2,400 MW and six generators has been completed much earlier than scheduled, bringing huge economic benefits Every year it will create a turnover of 500 million USD and save over five million tones of coal which will be needed to produce an equivalent amount of electricity Moreover, the plant will supply on average • w •:>r ! T3 S ỵ 03 Ư c3 -C a S f «i ■8 C !B S ! ü * C/3 13 c c H (■dw)f° **»*s (*dW> 1° HUIS F ïïïïỵ M X X X X X IJ0TJJ Xl iXTX IX I ! 1i I I §§§§§§ 8 8 11 (Ul) mumvydtfp |»)0j[ JO m m J J J Ü J g g U U V JB o c c c c c e ỵ! I i S 2 IU !V !II !V «! IV lililí 8 8 8 § 95599 1I £I £I III i l l \&&Í ii& S& i-,5i 1i 1¿ 2 2 I 1I i i i a & £ && & H H H H H H ? ? *r\ Uh *r> m ãS g ri f J9 ô 13 ofSJ tr \ "S O (•dW) '° o JB C/3 ü ï U « B Û _ a o (■JK) *«-0S /cd 407 ■ Éi w * u /cï Jü ỵ w o ~ (Ul) )UMU99«|dl>ip |«10X o O ! ! ü JS ï jü JQ O H •f-H U /ea Vietrock2015 an ISRM specialized conference Vietrock2015 12-13 March 2015, Hanoi, Vietnam To determinate optimal distance between two tunnels we have to establish the relationships of stress and displacement of rock mass at any points from this tunnel to other tunnels with other distances of them When the values of stress and displacement are equilibrium to initial stress, we can receive optimal distances between two tunnels By Examine 2D we can establish the relationship between stress and displacement of rock mass at the middle point of distance two tunnels as in figure Circular tunnels )«:-■■Tunnels with arc and vertical walls Horse shape tunnels 15 20 25 30 Distance between two tunnels, m a) Vertical stress in rock mass around two tunnels 0.0085 0.0075 E W ' Circular tunnels 0.0065 E QJ T unnels with arce an d vertical walls « 0.0055 a& H orse sh ap e tunnels 0.0045 0.0035 0.0025 + 10 15 20 25 30 35 Distance between two tunnels (m) b) Total displacement in rock mass around two tunnels Figure The relationship stress, displacement and distance between two tunnels Seeing results in figures and we can show that when stress becomes initial stress a = yH = 0,02x25 = 0,5MPa and displacement of rock mass at the middle point two tunnels are constant, we can receive optimal distance for two tunnels The results in analysis also show that in case two tunnels are circular, this distance is range from 20 to 25m, horse shape tunnels 30-35m, and two tunnels with arc and vertical walls 30-35m Conclusion By above analysis we can realize that excavation two tunnels is important problem in the field of underground construction The determination distance between two tunnels is very difficult to solve by the close solution methods but nowadays by numerical method base on boundary element method (BEM) in Examine 2D software results can be shown the distribution of stress and displacement of rock mass around two tunnels In case of tunnels are circular and excavated in detail geological conditions distance between them range from 20 - 25m ( - times radius of tunnel), tunnel horse 408 Vietrock2015 an ISRM specialized conference Vietrock2015 12-13 March 2015, Hanoi, Vietnam shape and tunnel with arc and vertical walls distance from this tunnel to other tunnels is 30 - 35m (5 times haft span of tunnels) Commonly, damage zone around excavated tunnels in case of two circular tunnels is ranged from -5 times radius of tunnels This result is the same as the results in the close solution method However, in this example because of changing tunnel shapes tunnels with arc and vertical walls and tunnel horse shape are less stability more than circular tunnel so distances between them are be increased with range from - times 1/2 tunnel span Analysis by modeling calculation will become more quickly than other methods, when setting support pressure inner tunnels we can estimate this distance for supported tunnels References [1] Nguyen Quang Phich, Rock mechanics, Ha Noi, 2007 [2] Nghiem Huu Hanh, Rock mechanics, Ha Noi, 2004 [3] Vo Trong Hung, Phung Manh Dac, Rock mechanics for underground construction and mining, Ha Noi, 2008 [4] Nguyen Quang Phich et al, Application research some numerical methods fo r calculation underground construction, B2005-36-88TD, Ha Noi, 2006 [5] B.H.G Brady and E.T.Brown (2004), Rock mechanics for underground mining, Dordecht [6] Dimitrios Kolymbas (2005), Tunnelling and tunnel mechanics, Springer - Verlag Berlin Heudelberg Germany [7] www.rocscience.com 409 ISBN: 978-604-913-372-5 V-/-4-V VIETROCK 2015 - an ISRM S P E C IA L IZE D C O N F E R E N C E 2015 VIETROCK 2015 International Symposium ISRM Marc^ 12' 13,2015 Hanoi,VietNam An informa business ... 2015, Hanoi, Vietnam Research on determination of optimal distance between two unsupported tunnels when consideration to shape changes Tran Tuan M inha Nguyen Duyen Phongb Ha Noi University o f... designations However, nowadays in Viet Nam this problem has many disadvantages This paper introduces the studying on determination of optimal distance between two transport tunnels when consideration. .. energy storage in a lined rock cavern 350 Won Kyung Song Construction Case of Underground Storage Cavern In India 351 Jaewon Ryu Lessons on the Hydrodynamic Containment Design and Construction o