Ertan Hydropower Development Co.

Miao’ertan, China

Ertan Hydropower Development Co.

Miao’ertan, China

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Huang R.,Chengdu University of Technology | Huang D.,Chengdu University of Technology | Huang D.,Chongqing University | Duan S.,Ertan Hydropower Development Co. | And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

Jinping I Hydropower Station located in the Southwest China is a key cascade and control underground hydropower project at the Yalong River. The project is very huge and the underground powerhouse system is very complicated, as well as the complex geological conditions, lower strength for rock relative to very high geostress especially. The challenge which no found in historical projects is presented by two dominate aspects in the construction. The two ones are stability and reinforce of surrounding rock. The characteristics of deformation split of surrounding rock and failure of supporting structure is described based on the geological conditions, monitor and geophysical prospecting, investigations in-situ and tests data. The correlations are discussed which deformation failure of surrounding rock and supporting structure with geostress, rock mass structure and mechanical property of rock under loading and unloading. The geomechanics mechanism of deformation failure of the surrounding rock and supporting structure is explained. The tangential loading stress is rather large and inclined to split pressed at downstream side(especially hance) of main powerhouse and main transformer house, but the normal unloading stress is rather larger and inclined to tension and relaxation unloaded because of the high geostress and its direction. The rheological behaviour of the fracture surrounding rock is presented, and is gradually charactered from surface to deep, the time-dependent deformation of fracture rock mass with surrounding rock relaxation is showed. The surrounding rock at downstream side is easy to bend and break-off and low susceptibility to shear and slide of main powerhouse and main transformer house under secondary stress field, because that the upstream side is bedding but the downstream inverse slope with low dip angles. The powerhouse marble is presented that relative lower strength, heavy brittle and lower strain strength, are easy to tension pressed under unloading.


Chen B.,CAS Wuhan Institute of Rock and Soil Mechanics | Feng X.,CAS Wuhan Institute of Rock and Soil Mechanics | Zeng X.,Ertan Hydropower Development Co. | Xiao Y.,CAS Wuhan Institute of Rock and Soil Mechanics | And 3 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

According to the difficulties and shortcomings of real-time microseismic monitoring during tunnel boring machine(TBM) tunneling with overburden of over 2 000 m-thick hard and brittle rock mass, the traditional microseismic monitoring technology, used in the mines, is optimized and improved; and the new microseismic monitoring technology is utilized during the TBM tunneling in the diversion tunnel #3 of Jinping II hydropower station. The monitoring results show as follows: (1) The ambient noise is much and complex, but the main characteristic is clear during TBM tunneling; and it can be filtered through the proposed filtering method effectively. (2) There is an obvious relationship that microseismic activity increases with the increase in TBM tunneling rate between microseismic activity of surrounding rock mass and the TBM tunneling rate, vice versa. Microseismic activity is very weak during the period of TBM maintenance, but it becomes most active when TBM working lasts for 4-6 hours after TBM maintenance. (3) Before some rockburst occurred, distribution of microseismic events and energy release gradually convert from discrete to relatively concentrative in spatial domain, the number of microseismic events and the radiated energy increase rapidly in temporal domain; and apparent volume of surrounding rock mass has a sudden increasing trend; energy index has a sudden drop trend in the same time. (4) When microseismic monitoring is carried out during TBM tunneling covered with thickly hard and brittle rock mass, effective microseismic information can be acquired; the evolution characteristic and law of microseismic activity can be found and known; and more accurate early-warning information of rockburst can be provided. Therefore, it is possible and feasible to forecast the occurrence of rockburst by microseismic monitoring.


Zhang C.,CAS Wuhan Institute of Rock and Soil Mechanics | Feng X.,CAS Wuhan Institute of Rock and Soil Mechanics | Zhou H.,CAS Wuhan Institute of Rock and Soil Mechanics | Zhang C.,China Power Engineering Consulting Group Corporation | Wu S.,Ertan Hydropower Development Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

The brittle failure modes and mechanism of surrounding rocks should be studied and understood primarily. Furthermore, the rational evaluation of the brittle failure degree is crucial importance for stability analysis and control of surrounding rock mass in deep underground engineering. The test tunnels in Jinping II Hydropower Station are exactly constructed for these problems, the buried depth of 2500 m is the maximum in the world. Based on the analysis of the experimental results, the engineering mechanical features of the marble T2b are studied. Then the failure modes and mechanism of the surrounding rock mass in the test tunnels are analyzed. And the range and depths of the failure zone in the test tunnels are calculated by numerical simulation method in which the constitutive model, RDM, for hard brittle marble and the FAI evaluation method are adopted. Finally, comparison between the calculated results and those revealed in the test tunnels is carried out. And the results obtained through comparison are satisfied. This study lays the solid foundation for the design of support parameters and establishment of the constructing measures in the excavation process of the diversion tunnels in this project.


Feng X.,CAS Wuhan Institute of Rock and Soil Mechanics | Chen B.,CAS Wuhan Institute of Rock and Soil Mechanics | Ming H.,CAS Wuhan Institute of Rock and Soil Mechanics | Wu S.,Ertan Hydropower Development Co. | And 4 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2012

The ideas and methodology for the in situ monitoring of rockburst preparation of deep tunnels was described firstly. The time and space evolution law of immediate rockburst observed, which occurred usually during or after excavation immediately and affected mainly by excavation unloading effectiveness, was analyzed. Based on a series of in situ monitoring of deep tunnels, process of crack initiation, propagation, opening and closing, evolution of wave velocity, deformation, acoustic emission and microseismicity were observed. Based on moment tensor analysis of the monitored microseismicity during the excavation of deep tunnels, the difference of mechanism of strain rockburst and strain-structure slip rockburst was found. The former was mainly from tensile cracking but the latter mainly from tensile cracking, shear cracking, and tensile-shear/compressive shear cracking which was from shearing of stiff structures and formed boundary of rockburst pit. The results are used as a guide of prediction of rockburst and its dynamic control based on evolution of the monitored microseismicity and other information.


Zhang G.-K.,Ertan Hydropower Development Co. | Xu W.-Y.,Hohai University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

The deformation of rock mass is considered as the summation of the linear elastic deformation of intact rock block and nonlinear elastic deformation of joints. On the basis of deformation characteristics of joints, a new constitutive model for normal displacement of joints is presented. It considers the influence of the initial stress state on the deformation. The computation method for jointed rock mass equivalent strain is studied by use of the joint network and the theory of equivalent continuous strain. According to the elastic orthotropic constitutive model, the rock mass is regarded as orthotropic continuous material, and the orthotropic equivalent deformation parameters are computed. The computation codes of orthotropic equivalent deformation parameters are developed. The example verification is carried out to test the rationality of the analytic results and the codes.


Shiyong W.,Ertan Hydropower Development Co. | Manbin S.,Ertan Hydropower Development Co. | Jian W.,Ertan Hydropower Development Co.
Bulletin of Engineering Geology and the Environment | Year: 2010

In 1978, the Jinping Project was designed as an integrated hydroelectric power scheme on the Yalong River in Southwest China. Jinping I involves a 305 m high arch dam on the upstream side of the Great Jinping River Bend. Water is directed through the mountains in four 16.7 km long, c.13 m diameter tunnels, beneath up to 2,525 m of overburden, to the Jinping II underground powerhouse where the head is 310 m. The combined schemes will produce 8,400 MW and an annual power generation of 40.8 TW. h. © 2010 Springer-Verlag.


Wu S.,Ertan Hydropower Development Co. | Wang G.,Ertan Hydropower Development Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

Jinping II hydropower station includes four diversion tunnels, two auxiliary tunnels and one drainage tunnel, with a total tunnel length of 118 km. These tunnels are characterized as thick overburden, long length, large size in diameter, high geostress, complicated engineering geological conditions and high difficulty for project layout, which make the tunnel project the largest and most difficult hydro-tunnel group in the world. Key technical problems were met during the tunnels excavation, including the forecast and treatment of groundwater, and the prevention of rock burst. The studies and measures adopted against rock burst, the gushing water and the instability of surrounding rock mass during the construction of tunnels are summarized. The experience accumulated during the construction of the tunnels in Jinping II hydropower station shall provide valuable reference for similar projects.


Wu S.,Ertan Hydropower Development Co. | Gong Q.,Beijing University of Technology | Wang G.,Ertan Hydropower Development Co. | Hou Z.,Yantai University | She Q.,Beijing University of Technology
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

During the tunnel boring machine(TBM) excavation, two types of slabbing failures in these deep-buried marble tunnels are discussed. One is violent slabbing rock burst and the other is non-voilent slabbing and spalling. In order to study the slabbing failure, true triaxial experiments for modeling the rock burst at different in-situ stresses are carried out. Results show that all of the specimens appeared slabbing. The phenomena observed in the experiments are very similar to that at the tunnel site in Jinping II hydropower station. The experiment explains basically the tunnel face and tunnel side rock failure phenomena at present, and also displays the main failure types during the TBM excavation in the future. The influence of the slabbing failure at tunnel face and tunnel side on TBM excavation is analyzed and discussed.


Huang S.,Yangtze River Scientific Research Institute | Xu J.,Ertan Hydropower Development Co. | Ding X.,Yangtze River Scientific Research Institute | Wu A.,Yangtze River Scientific Research Institute
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

The common character of layered rocks is transversely isotropic due to the existence of regular bedding planes, which means that the failure mechanism and deformation characteristics of such rocks have the obvious difference with common rocks. In view of this point, a strain hardening-softening composite model of layered rock mass is proposed according to the physico-mechanical characteristics of structural plane and rock matrix, and it can be used to describe the anisotropic characteristics of rock strength and deformation, as well as progressive failure or sliding characteristics. Then, the proposed model has been successfully established and embedded on the basis of the third developing platform of constitutive model in FLAC3D, realizating nonlinear numerical calculation. The results including the comparison with classical theoretical solutions and numerical solutions, simulation of uniaxial and triaxial compressions of layered rock mass and so on prove that the proposed model is suitable for the description of the above characteristics. At the same time, the mechanical response characteristics and progressive failure processes of test blocks with different confined pressures and different dip angles are analyzed; and the failure or sliding mechanism of such rocks is discussed so as to better understand the mechanical properties. Finally, the proposed model is used to simulate a typical slope project and a cavern project; and the simulation results can be used to better explain in-situ deformation and failure phenomenon, and they are in accordance with engineering practice. It is shown that the proposed model is correct and feasible for the engineering application.


Gong Q.M.,Beijing University of Technology | Yin L.J.,Ecole Polytechnique Federale de Lausanne | Wu S.Y.,Ertan Hydropower Development Co. | Zhao J.,Ecole Polytechnique Federale de Lausanne | Ting Y.,Beijing University of Technology
Engineering Geology | Year: 2012

Two headrace tunnels and the drainage tunnel were excavated by tunnel boring machines (TBMs) in Jinping II Hydropower Station. During TBM excavation, two types of slabbing failure were encountered in these deep buried marble tunnels. One is rock bursting and the other is non-violent slabbing. In order to study the rock burst and slabbing failure, a unique true triaxial rock burst test was carried out to simulate the rock burst process with different in situ stresses. Four rock samples in different marble layers were obtained in the site, and then four experiments are conducted under the same stressed conditions as the in situ field. The rock burst process and slabbing failure phenomena of the four experiments are in good accordance with the observations of corresponding excavation site. The failure modes of slabbing and rock burst in different rock groups can be predicted based on the experiments. The influence of the slabbing and rock burst failure on TBM excavation is analyzed in depth. Non-violent slabbing is beneficial to the rock breakage process. Rock burst with violent slabbing process greatly affects the tunnel support, cutter and cutterhead damage, gripper movement and force and so on. © 2011 Elsevier B.V.

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