scholarly journals Microseismic Monitoring of Energy Changes in Deep Tunnels during the TBM Tunneling of the Jinping II Hydropower Station

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Duanyang Zhuang ◽  
Ke Ma ◽  
Chunan Tang ◽  
Zhengzhao Liang ◽  
Zhenwei Wang
Keyword(s):  
Control Method ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Rock Masses ◽  
Spatial And Temporal Patterns ◽  
Tunnel Section ◽  
Headrace Tunnel ◽  
Jinping Ii Hydropower Station ◽  
And Control

The TBM tunneling at the Jinping II hydropower station in Southwest China has received extensive concerns around the world because of its large engineering scale and the high rockburst risks faced in the tunnel advancement. The associated energy changes of rockbursts and control method for safe TBM tunneling are to be further investigated. A movable microseismic (MS) monitoring system was established to capture the MS events and rockbursts when the TBM excavated the headrace tunnel #1 at the Jinping II hydropower station. The spatial and temporal patterns of the energy changes in the tunnel rock masses were studied. Meanwhile, the evolution of a rockburst encountered in front of the TBM excavation face was revealed, and the performance of the top pilot tunnel method on the reduction of the rockburst risks in the headrace tunnel #1 was evaluated based on the energy changes of the surrounding rock masses. It can be concluded that energy accumulation and energy release firstly occurred in the surrounding rock masses at the southern end of the top pilot tunnel section of the headrace tunnel #1. Then, energy transference of the rock masses took place from the southern end to northwest of the top pilot tunnel giving rise to the occurrence of a moderate rockburst about 30 m in front of the tunnel. However, no rockbursts appeared when the TBM excavated through the top pilot tunnel section of the headrace tunnel #1. Therefore, the top pilot tunnel method really works in reducing the risks of rockbursts during the TBM tunneling in deep tunnels.

Analysis of Surrounding Rock Deformation Based on M-C Model and Cvisc Model

2013 ◽  
Vol 295-298 ◽  
pp. 2963-2966
Author(s):  
You Xiang Li
Keyword(s):  
Surrounding Rock ◽  
Rock Deformation ◽  
Hydropower Station ◽  
Deformation Characteristics ◽  
Diversion Tunnel ◽  
Software Application ◽  
Jinping Ii Hydropower Station ◽  
Coulomb Model ◽  
Plastic Zones ◽  
Surrounding Rock Deformation

According to the analysis of the surrounding rock deformation of the buried sandy slate, which is 1500-2000m depth of Diversion Tunnel Jinping-II Hydropower Station, the essay uses FLAC software application to analyze the deformation characteristics and plastic zones of the sandy slate, study comparatively the influence of Mohr-Coulomb model and Cvisc model to the surrounding rock, and then draw some conclusions, including that calculations derived by using Cvisc model is more in line with the actual engineering.

scholarly journals A Review of the Transient Process and Control for a Hydropower Station with a Super Long Headrace Tunnel

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2994 ◽  
Author(s):  
Wencheng Guo ◽  
Daoyi Zhu
Keyword(s):  
Design Optimization ◽  
Transient Process ◽  
Operating Conditions ◽  
Research Progress ◽  
Hydropower Station ◽  
Operation Conditions ◽  
Hydraulic Design ◽  
Headrace Tunnel ◽  
And Control ◽  
Hydropower Stations

The hydropower station with a super long headrace tunnel is a significant development type for hydropower energy. By constructing a super long headrace tunnel, the huge natural water fall head can be utilized to generate more electricity. With the development of hydropower energy, a hydropower station with a super long headrace tunnel becomes more and more competitive. Compared with a hydropower station with a short headrace tunnel, the transient process and control for a hydropower station with a super long headrace tunnel is much more complicated and becomes an intractable challenge. It is well known that the transient process and control is the basis of the design and operation of a hydropower station. To overcome the challenge of the transient process and control, much research has been carried out. This paper provides a systematic review on the latest research progress of the transient process and control for hydropower stations with a super long headrace tunnel. Firstly, two key issues for the transient process and control, i.e., hydraulic design optimization of the surge tank and operation control of unit, are illuminated. Secondly, for both single surge tanks and surge tanks with special types or combinations, the hydraulic design optimization methods are described. The most disadvantageous design and advantageous operation of surge tanks under combined operating conditions are discussed. Thirdly, the stability and regulation quality of the hydro-turbine governing system under isolated and grid-connected operation conditions are presented. Finally, some trends and recommendations for future research directions are made. A research thought for establishing the complete theory and application system of the transient process and control for hydropower stations with a super long headrace tunnel from the perspective of multi-slice and multi-scale is proposed.

Study on Design of Tunnel Section for Danba Diversion Tunnel

2014 ◽  
Vol 501-504 ◽  
pp. 1732-1735
Author(s):  
Jie Liu ◽  
Liang Tang ◽  
Ya Zuo ◽  
Jin Long Guo
Keyword(s):  
Stability Analysis ◽  
Plastic Zone ◽  
Cross Sections ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Diversion Tunnel ◽  
Rock Stability ◽  
Tunnel Section ◽  
Tunnel Design ◽  
The Stability

Analyzing and Evaluating the stability of the surrounding rock is an indispensable and important part in the tunnel design. In this paper, the surrounding rock stability of Danba hydropower station diversion tunnel is dealt with, FLAC3Dsoftware is used for stability analysis. Selecting three different cross sections for calculation models, comparing with the displacement and principal stress and the plastic zone which calculated by FLAC3D, we can evaluate their stability and get the best diversion tunnel design.

scholarly journals A Microseismicity-Based Method of Rockburst Intensity Warning in Deep Tunnels in the Initial Period of Microseismic Monitoring

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2698 ◽  
Author(s):  
Guangliang Feng ◽  
Manqing Lin ◽  
Yang Yu ◽  
Yu Fu
Keyword(s):  
Cluster Analysis ◽  
Geotechnical Engineering ◽  
Initial Period ◽  
Engineering Application ◽  
Microseismic Monitoring ◽  
Sichuan Province ◽  
Economic Losses ◽  
Hydropower Station ◽  
The Novel ◽  
Jinping Ii Hydropower Station

Rockburst disasters in deep tunnels cause serious casualties and economic losses. It is a great challenge to make a warning for rockbursts in geotechnical engineering. In this work, a microseismicity-based rockburst intensity warning method is proposed that is suitable for use in deep tunnels in the initial period of microseismic (MS) monitoring. The method first involves collecting information on a sample of no more than five cases. Then, the event to be analyzed is combined with the sample events and subjected to cluster analysis. Finally, a rockburst intensity warning is generated according to the results of the cluster analysis or after a second cluster analysis. It is a comprehensive, multi-parameter rockburst intensity warning method that only needs a few rockburst cases for input which makes it suitable in the initial period of MS monitoring. The method also incorporates the novel idea of a second cluster analysis. An engineering application based on deep tunnels in the Jinping II hydropower station in Sichuan Province, China, shows that the rockburst intensity warning results based on the proposed method agree well with the actual situations in four tests carried out. The method will enrich the techniques used to warn of rockbursts based on microseismicity.

scholarly journals Stability of Close Chambers Surrounding Rock in Deep and Comprehensive Control Technology

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Weijian Yu ◽  
Fangfang Liu
Keyword(s):  
Control Method ◽  
Large Diameter ◽  
High Stress ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Technology ◽  
Internal Damage ◽  
Anchor Cable ◽  
The Stability ◽  
And Control

The purpose of this paper is to solve the problem that deep and close-distance cavern and roadway group were easily affected by the adjacent chamber or roadway excavation disturbance and low stability and significant deformation of surrounding rock occurred. The stability and control technology of surrounding rock in the main shaft and auxiliary shaft system has been analyzed by the adjacent chamber and roadway group of −850 m level in Qujiang Mine, China, as an engineering background. Firstly, the numerical calculation of the excavation chamber was, respectively, carried out in different ways with the propagation theory of the excavation disturbance wave. The results show that the interaction of adjacent chamber excavation was more intense. When excavated at the same time, there is a large increase in the movement of the sides and the roof-floor of the chamber and roadway. Then, the mechanism of interaction between low-high stress and excavation disturbance was considered, the corresponding control principles were provided, and a set of critical technologies and equipment were designed according to the deformation characteristics of the large deformation soft surrounding rock. Finally, the comprehensive control method was put forward with the water pump house as an example, that is, anchor, metal net, grouting, combined anchor cable and large-diameter anchor cable. And the related support parameters were determined by the internal damage of the surrounding rock chamber. The numerical simulation results show that the surrounding rock deformation of the chamber and roadway reduced with the revised support program, which the expansion of the rock mass loose circle prevented effectively. The site test shows that the convergence rate of surrounding rock with the improved support was less than 0.2 mm/d, and the rock deformation of chamber and roadway suppressed significantly.

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