Measurements and application of in-situ stress and related rock mechanics parameters at a new type of diversion hydroelectric project in Southwest China

2010 ◽  
pp. 485-491
Author(s):  
Shuxin Yang ◽  
Chenghu Wang ◽  
Rui Yao ◽  
Qi Mi
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jianan Li ◽  
Heping Xie ◽  
Ling Chen ◽  
Cong Li ◽  
Zhiqiang He

Exploration of deep-rock mechanics has a significant influence on the techniques of mining and rock mechanics. Rock coring technique is the basic method for all rock mechanics study. With the increase of the drilling depth and increasing strength of the hard rock, how to obtain high-quality rock core through various coring techniques is an eternal work. Here an innovative method is applied to design the new coring system to maximize the efficiency of operation. The stress conditions or parameters of rock core in the coring are analyzed, and the mechanism of the core with in situ stress is shown in this paper. The conflict of the core and coring tool chamber is proposed for the innovative design. The innovative design method is fulfilled by the theory of inventive problem solving (TRIZ). An improved coring system for the full-length core with in situ stress was obtained with the solutions of improved coring mechanism, cutting mechanism, and spiral drill pipe.


2021 ◽  
Vol 11 (5) ◽  
pp. 2199-2206
Author(s):  
Sheng Ya-nan ◽  
Li Weiting ◽  
Jiang Jinbao ◽  
Lan Kai ◽  
Kong Hua ◽  
...  

AbstractThe complex geological conditions of drilling, the difficulty of formation collapse and fracture pressure prediction in South Sichuan work area lead to the complex drilling and frequent failure, which seriously restricts the safe and efficient development of shale gas. In view of this problem, this paper has carried out relevant research. First of all, the existing calculation model of formation collapse and fracture pressure is established and improved; on this basis, the sources of uncertainty in the calculation model of collapse and fracture pressure are analyzed, mainly the in-situ stress and rock mechanics parameters, which have a lot of uncertainties; then, the uncertainty of rock mechanics parameters and in-situ stress is analyzed, and its probability is determined. Finally, based on Monte Carlo simulation, the quantitative characterization method of formation collapse and fracture pressure uncertainty is established. The prediction result of collapse and fracture pressure is no longer a single curve or value, but an interval, which is more practical for drilling in complex geological environment. The results of this study are helpful to better describe the collapse and fracture pressure of complex formation and can provide more valuable reference data for drilling design.


2018 ◽  
Vol 23 ◽  
pp. 42-47
Author(s):  
Krishna Kanta Panthi ◽  
Chhatra Bahadur Basnet

 The in-situ stress condition in the rock mass is influenced by both tectonic and geological environment, such as faulting and shearing in the rock mass. This influence is of considerable magnitude in the Himalayan region where the tectonic movement is active, resulting periodic dynamic earthquakes. Each large-scale earthquake causes both accumulation and sudden release of strain energy instigating changes in the in-situ stress environment in the rock mass. This paper evaluates the influence of local shear fault on the in-situ stress state along the shot crete lined high pressure tunnel of Upper Tamakoshi Hydroelectric Project, 456 MW in Nepal. A detailed assessment of the in-situ stress state is carried out by using both; measured data and three-dimensional numerical analysis using FLAC3D. The analysis includes evaluation on the possible changes in the in-situ stress state in the rock mass caused by seismic activities (dynamic loading). HYDRO Nepal JournalJournal of Water, Energy and Environment Issue: 23Year: 2018


2017 ◽  
Vol 21 ◽  
pp. 34-41
Author(s):  
Chhatra Bahadur Basnet ◽  
Krishna Kanta Panthi

Reliable estimation of in-situ stress state is very important in implementing the shotcrete lined/ unlined tunnels and shafts. The in-situ stress state of the area of concern is mainly governed by the gravity-induced stress, tectonic activity of the earth’s crust and topographic condition of that area. The local tectonic and geological environment such as faulting and shearing activities in general influences the magnitude of tectonic stress level. The Himalayan region is renowned with its active tectonic movement (earthquake activities), which causes accumulation and sudden release of strain energy instigating changes in the stress environment. This paper aims to evaluate in-situ stress state at the Upper Tamakoshi Hydroelectric Project, where shotcrete lined/ unlined headrace tunnel with considerable hydrostatic head is being implemented. A detailed assessment of the in-situ stress state is carried out by using both measured data and three-dimensional numerical analysis using FLAC3D. HYDRO Nepal JournalJournal of Water Energy and EnvironmentIssue: 21, July, 2017Page: 34-41Upload Date: July 18, 2017


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