Key block theory application for surrounding rock mass of underground powerhouse in Dagangshan Hydropower project

2013 ◽  
pp. 371-376
Author(s):  
J Dong ◽  
G Xu ◽  
Z Li ◽  
Y Shen ◽  
J Teng
Keyword(s):  
Rock Mass ◽  
Surrounding Rock ◽  
Hydropower Project ◽  
Block Theory ◽  
Underground Powerhouse ◽  
Theory Application ◽  
Key Block

Application of Stereographic Projection in the Search of Key Block of Surrounding Rock Mass for Underground Powerhouse

2010 ◽  
Vol 44-47 ◽  
pp. 1189-1192
Author(s):  
Zhong Chang Wang
Keyword(s):  
Rock Mass ◽  
Stereographic Projection ◽  
Side Wall ◽  
Surrounding Rock ◽  
Main Role ◽  
Measuring Point ◽  
Underground Powerhouse ◽  
Underground Caverns ◽  
Key Block ◽  
The Stability

The rose diagram of joint is generalized by grouping the attitude of disclosed discontinuous faces in detecting cavern and measuring point coordinate. The search of movable and key blocks of surrounding rock mass for underground powerhouse is implemented, the combinations of discontinuous faces and sliding faces, the location and the parameter of stability of movable and key blocks are obtained by used of the method of stereographic projection and vector analysis of the block theory. It is shown that the numbers of movable and key blocks in the location of downriver right side wall and vault are larger than those in other location owing to numerous discontinuous faces, and the faults of F34 and F33 play a main role in the stability of movable and key blocks. The guidance for excavation and reinforce of underground caverns is provided.

scholarly journals Key Factors Affecting the Deformation and Failure of Surrounding Rock Masses in Large-Scale Underground Powerhouses

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Meng Wang ◽  
Jia-wen Zhou ◽  
An-chi Shi ◽  
Jin-qi Han ◽  
Hai-bo Li
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Surrounding Rock ◽  
Rock Masses ◽  
Affecting Factors ◽  
Key Factors ◽  
Underground Powerhouse ◽  
Deformation And Failure ◽  
Factors Affecting ◽  
Geological Conditions

The stability of the surrounding rock masses of underground powerhouses is always emphasized during the construction period. With the general trends toward large-scale, complex geological conditions and the rapid construction progress of underground powerhouses, deformation and failure issues of the surrounding rock mass can emerge, putting the safety of construction and operation in jeopardy and causing enormous economic loss. To solve these problems, an understanding of the origins and key affecting factors is required. Based on domestic large-scale underground powerhouse cases in the past two decades, key factors affecting the deformation and failure of the surrounding rock mass are summarized in this paper. Among these factors, the two most fundamental factors are the rock mass properties and in situ stress, which impart tremendous impacts on surrounding rock mass stability in a number of cases. Excavation is a prerequisite of surrounding rock mass failure and support that is classified as part of the construction process and plays a pivotal role in preventing and arresting deformation and failure. Additionally, the layout and structure of the powerhouse are consequential. The interrelation and interaction of these factors are discussed at the end of this paper. The results can hopefully advance the understanding of the deformation and failure of surrounding rock masses and provide a reference for design and construction with respect to hydroelectric underground powerhouses.

Establishment and Application of Microseismic Monitoring System to Deep-Buried Underground Powerhouse

2013 ◽  
Vol 838-841 ◽  
pp. 889-893
Author(s):  
Biao Li ◽  
Feng Dai ◽  
Nu Wen Xu ◽  
Chun Sha
Keyword(s):  
Rock Mass ◽  
Monitoring System ◽  
Wave Velocity ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
P Wave ◽  
Monitoring Method ◽  
Underground Powerhouse ◽  
Geological Conditions ◽  
The Stability

The right bank underground powerhouse of Houziyan hydropower station is a typical deep-buried type with high geostress and complicated geological conditions. To monitor and analyze the stability of surrounding rock mass during continuous excavation of the powerhouse excavation and locate the potential failure zones, an ESG (Engineering Seismology Group) microseismic monitoring system manufactured in Canada was installed in April, 2013. The wave velocity of the monitoring system was determined through fixed blasting tests. And the average location error is the minimum while P-wave velocity is 5700m/s, less than 10m and meeting the system request. By combining the temporal and spatial distribution regularity of microseimic events with field excavation, micro-crack clusters and potential instability zones were identified and delineated. The results will provide a reference for later excavations and supports of the underground powerhouse. Furthermore, a new monitoring method can also be supplied for the stability analysis of surrounding rock mass in deep-buried underground powerhouses.

scholarly journals Deformation and Failure Analyses of the Surrounding Rock Mass with an Interlayer Shear Zone in the Baihetan Underground Powerhouse

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Fei Yuan ◽  
An-chi Shi ◽  
Jia-wen Zhou ◽  
Wang-bing Hong ◽  
Meng Wang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Shear Deformation ◽  
Shear Zone ◽  
Failure Modes ◽  
Shear Zones ◽  
Surrounding Rock ◽  
Left Bank ◽  
Underground Powerhouse ◽  
Deformation And Failure ◽  
Interlayer Shear

In the process of underground cavern excavation, the existence of the interlayer shear zones or large faults often makes the surrounding rock tend to be unstable or even deformed. Under the influence of interlayer shear zone C2, different degrees of deformation and failure occurred in many parts during the excavation of the Baihetan left bank underground powerhouse. Based on field monitoring and numerical calculation, this paper studies the deformation and failure characteristics of the rock mass with C2 in the whole excavation process and the failure mechanisms are analyzed. The results show that C2 has poor mechanical properties. In the process of excavation, it mainly induces two failure modes: rock collapse and shear deformation, which specifically leads to rock collapses, large deformation and shotcrete cracking in the main powerhouse, and shear deformation in the omnibus bar caves. In addition, the similarities and differences between this study and other studies on the deformation and failure of surrounding rock of underground powerhouse in recent years are discussed, and the relevant treatment measures for C2 are given. The above research results can be a reference for other related studies.

Stability analysis of underground surrounding rock mass based on block theory

2020 ◽  
Vol 27 (10) ◽  
pp. 3040-3052
Author(s):  
Jian-yun Lin ◽  
Yu-jun Zuo ◽  
Jian Wang ◽  
Lu-jing Zheng ◽  
Bin Chen ◽  
...  
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Surrounding Rock ◽  
Block Theory

scholarly journals Stability Analysis and Reliability Evaluation in Cataclastic Loose Rock Mass Blocks

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Liguo Zhang ◽  
Dong Wang ◽  
Guanghe Li ◽  
Jiaxing Dong ◽  
Junpeng Zhang
Keyword(s):  
Rock Mass ◽  
System Reliability ◽  
Laser Scanning ◽  
Failure Modes ◽  
Reliability Evaluation ◽  
Rock Slopes ◽  
Hydropower Project ◽  
Rock Masses ◽  
Cataclastic Rock ◽  
Key Block

Cataclastic rock masses with multiple failure modes and mechanisms are critical geological problems in the construction of rock slopes. Cataclastic rock masses are widely distributed in slopes of a hydropower project located on Lancang River, which is located in Tibet, China. In this study, the potentially unstable block of the slope is divided into key block and secondary key block based on the key block theory, and the system reliability evaluation theory is introduced. The method for quantitatively analyzing the rock mass stability of cataclastic slopes with sliding failure is established. Then, the spatial distribution of cataclastic rock masses and discontinuities in several rock slopes of a hydropower project are determined using traditional geological surveying and 3D laser scanning. At last, combining the BATE 2.0 software and the stereographic projection of the vector, the proposed method is applied to the study area. The results show that the main failure mode of the studied slope is wedge failure, and the system reliability is 1.69. With the increase in the instability probability of the key block, the increase in the instability probability of the system block is obvious, which reflects the controlling effect of the key block on the stability of the system block. The calculated system instability probability is slightly larger than the key block instability probability.

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