Deformation and cracking of an underground powerhouse cavern system under high in-situ stress

2018 ◽  
pp. 171-180
Author(s):  
J.B. Wei ◽  
J.H. Deng
Keyword(s):  
In Situ Stress ◽  
Underground Powerhouse ◽  
High In Situ Stress

scholarly journals Optimization Analysis of Excavation Procedure Design of Underground Powerhouses under High In Situ Stress in China

2021 ◽  
Vol 11 (21) ◽  
pp. 10252
Author(s):  
Xiao Liu ◽  
Peng Yan ◽  
Ming Chen ◽  
Sheng Luo ◽  
Ang Lu ◽  
...  
Keyword(s):  
Stress Level ◽  
In Situ Stress ◽  
Complex Stress ◽  
Design Parameters ◽  
Rock Classification ◽  
Underground Powerhouse ◽  
High In Situ Stress ◽  
Blasting Excavation ◽  
Stress Levels

To recommend the excavation procedures and design parameters for underground powerhouses, excavation procedures of fifty-one underground powerhouses in China were summarized and analyzed based on in situ stress conditions. Firstly, the complex stress environment in China was introduced and fifty-one underground powerhouses with their engineering scale, size, lithology, rock classification and in situ stress level were listed in detail. Subsequently, to evaluate the influence of in situ stress levels on excavation procedure design, the correlation between excavation procedures and in situ stress level in three main excavation zones were analyzed accordingly. Moreover, to provide the excavation design recommendations, the strength–stress ratio (SSR) was promoted to analyze and recommend the design parameters, and the blasting excavation design based on the stress transient unloading control was also supplemented. The results show that excavation procedures have different priorities under different in situ stress levels, and the design parameters show an obvious relationship with in situ stress levels. Moreover, the excavation procedure parameters are suggested to adjust accordingly under different SSR. The discussion of influencing factors and specification ensures its rationality and accuracy. It is believed that the summary and recommendations can provide a good reference for excavation procedure optimization of underground powerhouse under high in situ stress.

Study on Deformation and Damage of Rock Mass Subject to High In Situ Stress by Using a Elastoplastic Damage Model and Considering the Impact of Weak Planes

2013 ◽  
Vol 838-841 ◽  
pp. 705-709
Author(s):  
Yun Hao Yang ◽  
Ren Kun Wang
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Damage Model ◽  
Back Analysis ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
High In Situ Stress ◽  
Underground Caverns ◽  
The Impact

Large scale underground caverns are under construction in high in-situ stress field at Houziyan hydropower station. To investigate deformation and damage of surrounding rock mass, a elastoplastic orthotropic damage model capable of describing induced orthotropic damage and post-peak behavior of hard rock is used, together with a effective approach accounting for the presence of weak planes. Then a displacement based back analysis was conducted by using the measured deformation data from extensometers. The computed displacements are in good agreement with the measured ones at most of measurement points, which confirm the validities of constitutive model and numerical simulation model. The result of simulation shows that damage of surrounding rock mass is mainly dominated by the high in-situ stress rather than the weak planes and heavy damage occur at the cavern shoulders and side walls.

Research of Mining Method for Difficult-to-Mine Ore Bodies in Deep Mine

2014 ◽  
Vol 962-965 ◽  
pp. 1041-1046
Author(s):  
Qi Fa Ge ◽  
Xue Sen Sun ◽  
Wei Gen Zhu ◽  
Qing Gang Chen
Keyword(s):  
In Situ Stress ◽  
Mining Method ◽  
Deep Mining ◽  
Deep Mine ◽  
Ore Body ◽  
High In Situ Stress ◽  
Ore Bodies ◽  
Large Panel ◽  
Back Filling

There are many problems such as depth, high in-situ stress, high ground temperature and rockburst proneness etc. in deep mining. And it is an acknowledged and urgent mining technical puzzle about mining method of gently inclined and medium-thick ore bodies. For such an ore body in West wing of Dongguashan copper mine, if we use traditional mining method, it is hard to conquer such difficulties as high in-situ stress, large open area in roof, removal of mined ore by gravity etc. The theory of “large panel and lower sublevel height” will be easy to solve such problems. This paper use numerical technology to analyze and compare the technical and economical effectiveness for different selected mining method and its structure. The sublevel (at a height of 12 m) open stoping with back-filling by extraction in two steps is quite suitable for ensuring safety, increasing efficiency, productivity and reclaiming resource. The selected method is feasible and well worth spread.

Coring damage extent of rock cores retrieved from high in-situ stress condition: A case study

2017 ◽  
Vol 21 (7) ◽  
pp. 2946-2957 ◽  
Author(s):  
Peng Yan ◽  
Qi He ◽  
Wenbo Lu ◽  
Yanli He ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Stress Condition ◽  
In Situ Stress ◽  
High In Situ Stress ◽  
Rock Cores ◽  
Damage Extent

scholarly journals Comparative Study of the Excavation Damage and Rockburst of the Deeply Buried Jinping II Diversion Tunnels Using a TBM and the Drilling-Blasting Method

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jing Yang ◽  
Xing-Guo Yang ◽  
Jia-Wen Zhou ◽  
Yong Liu ◽  
Bao-Shun Dong ◽  
...  
Keyword(s):  
Rock Mass ◽  
Stress Concentration ◽  
High Stress ◽  
Tunnel Boring Machine ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
High In Situ Stress ◽  
Damaged Zone ◽  
Blasting Method

The rock mass failure induced by high in-situ stresses during the excavation of deep diversion tunnels is one of the key problems in the construction of the Jinping II Hydropower Station. Based on the results of acoustic wave tests and rockburst statistical analysis conducted, this study focuses on the excavation damaged zone (EDZ) and rockburst events in the Jinping II diversion tunnels excavated using the tunnel boring machine (TBM) method and the drilling-blasting method. The unloading failure mechanism and the rockburst induced by the two different excavation methods were compared and analyzed. The results indicate that, due to the different stress adjustment processes, the degree of damage to the surrounding rock mass excavated using the drilling-blasting method was more serious than that using the TBM method. The EDZ induced by the TBM was usually distributed evenly along the edge of the excavation surface. While, the drilling-blasting method was more likely to cause stress concentration, resulting in a deeper EDZ in local areas. However, the TBM excavation method can cause other problems in high in-situ stress areas, such as strong rockbursts. The drilling-blasting method is more prone to structural controlled failure of the surrounding rock mass, while the TBM method would induce high stress concentration near the edge of excavation and more widely distributed of stress adjustment induced failure. As a result, the scale and frequency of the rockburst events generated by the TBM were significantly greater than those caused by the drilling-blasting method during the excavation of Jinping II diversion tunnels. The TBM method should be used carefully for tunnel excavation in high in-situ stress areas with burial depths of greater than 2000 m. If it is necessary to use the TBM method after a comprehensive selection, it is suggested that equipment adaptability improvement, advanced prediction, and prediction technology be used.

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