Research on the Spacing of Structural Plane Used in Rock Mass Structure Classification

2012 ◽  
Vol 446-449 ◽  
pp. 2011-2014
Author(s):  
Ai Guo Han ◽  
Min You ◽  
De Xin Nie
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Structure Type ◽  
Engineering Properties ◽  
Rock Mass Structure ◽  
Structural Plane ◽  
Hydroelectric Project ◽  
Quality Classification ◽  
Structure Research ◽  
Made In

Great achievements have been made in rock mass structure research to evaluate engineering properties of rock mass in the engineering geology field. In fact, rock mass structure can not only indicate the quantity of structural planes (discontinuities) and size of rock blocks, but also indicate the integrity and mechanical properties of the rock mass. More and more attention has been paid to rock mass quality classification by using rock mass structure. During the past 40 years, rock mass structure research has been carried out by many scholars, and various standards of rock mass structure classification have been proposed in different industries of different countries. In these standards, the most widely used index was the spacing of structural plane. However, it is a pity that the method of determining the spacing value is not unified in different standards, therefore, the structure type of a rock mass may be different according to different standard. But which kind of method to determine the spacing value is most reasonable? It becomes an important problem to be solved. In this paper, rational method of determining the spacing of structural planes is demonstrated based on lots of statistical data in dam abutment rock mass of one large-scale hydroelectric project in Southwest China.

scholarly journals Engineering geological and geotechnical investigations of dam of the Bunakha Hydroelectric Project (180 MW), Chukha Dzong, Bhutan Himalaya

2014 ◽  
Vol 47 (1) ◽  
pp. 77-94 ◽  
Author(s):  
A. K. Naithani ◽  
P. C. Nawani ◽  
L. G. Singh ◽  
D. S. Rawat
Keyword(s):  
Rock Mass ◽  
Shear Zones ◽  
Geological Mapping ◽  
Engineering Properties ◽  
Concrete Gravity Dam ◽  
Hydroelectric Project ◽  
Laboratory Test Results ◽  
Geotechnical Investigations ◽  
Tehri Dam

A 197 m high roller compacted concrete gravity dam is proposed across river Wang Chhu in Chukha Dzong of the Bhutan Himalaya. Bunakha Dam will be the third highest dam constructed by India after the Tehri Dam and Bhakra Dam. The Bunakha Dam site area is located in the Thimpu Formation of the Himalayan crystalline complex. This litho-units at site is characterized by heterogeneous lithology consisting of viz.  banded gneisses, foliated gneisses, with large boudins and bands of quartzite and calc-silicate gneisses with large porphyroblasts of garnet measuring up to 4 mm. These litho units form the foundation of proposed dam. In this paper attempt has been made to bring out the rock mass condition of the foundation of dam of the proposed scheme on the basis of detailed engineering geological mapping, geological logging of drill holes, rock mass permeability values, 3D mapping of exploratory drifts, geophysical profiling, in-situ and laboratory test results. Rock mass classification using Rock Mass Rating (RMR) system and Q-system was done. The basic purpose of these investigations was to identify/map different rocks and structures like joints, shear zones, faults, fracture zones etc. and to determine engineering properties of rock and rock mass by lab and in-situ testing and to provide basic data for economic and fail-safe design of the dam. On the basis of these investigations suitable recommendations have been made which will be helpful during the construction of the dam. 

Fractal of Frequency of Joints and its Application in Rock-Mass Structure

2011 ◽  
Vol 368-373 ◽  
pp. 3575-3578
Author(s):  
Yan Hui Song ◽  
Ying Wang
Keyword(s):  
Rock Mass ◽  
Southwest China ◽  
Structure Type ◽  
Power Engineering ◽  
Power Station ◽  
Rock Mass Structure ◽  
Water Power

Developmental degree of the rock-mass joint is often obtained through the exploratory adit in water-power engineering and it is the vital index for evaluating rock-mass structure and quality. In this paper, easy algorithm for the fractal of frequency of joint is established by a case in a certain power station in southwest China, through this method, the fractal of the rock-mass structure in different adit sectors can be gotten easily and thus the structure type of the rock-mass can be separated from each other according to the fractal value.

scholarly journals A dynamic analysis of in-situ stress state at the Upper Tamakoshi Hydroelectric Project area, Nepal

2018 ◽  
Vol 23 ◽  
pp. 42-47
Author(s):  
Krishna Kanta Panthi ◽  
Chhatra Bahadur Basnet
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Large Scale ◽  
Three Dimensional ◽  
In Situ Stress ◽  
Energy And Environment ◽  
Hydroelectric Project ◽  
Detailed Assessment ◽  
Local Shear

 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

Evolution Mechanism Study to the Loose-Fractured Rockmasses of Badong Group in Fengjie New Town

2012 ◽  
Vol 594-597 ◽  
pp. 589-595
Author(s):  
Le Yang ◽  
Hai You Peng ◽  
Mo Lin Zhou ◽  
Jian Guo Yang ◽  
Meng Wu
Keyword(s):  
Rock Mass ◽  
Influencing Factors ◽  
Fractured Rock ◽  
Engineering Properties ◽  
Mechanism Study ◽  
Fractured Rock Mass ◽  
Rock Mass Structure ◽  
Evolution Mechanism ◽  
New Town ◽  
Formation And Evolution

The loose-fractured rock mass of Badong formation exposed stratum in New Fengjie county is a typical unsteadiness rock group, possessing unique formation and evolution mechanism of rock mass structure and engineering properties. This paper mainly aiming at the influencing factors such as the tectonic action, formation lithology, the effect of water and so on, analyzes and researches the causes and evolution mechanism of the loose-fractured rock mass of Badong formation in New Fengjie county.

The Stability of a Rock Dam Site under Seismic Conditions

2011 ◽  
Vol 94-96 ◽  
pp. 1848-1857
Author(s):  
Jin Hu ◽  
Xue Zhi Yang ◽  
Yong Zhang ◽  
Jun Ye Zhong
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Yellow River ◽  
Seismic Intensity ◽  
Rock Mass Structure ◽  
Seismic Acceleration ◽  
Dam Foundation ◽  
Dam Site ◽  
The Stability ◽  
The Right

This paper takes the Daliushu Dam Site in Yellow River as an example, which is located near the active fault zone with high seismic intensity. It studies the seepage of dam abutment rock mass in meizoseismal area and the stability under earthquake condition. The assessments on the key engineering problems of this project are based upon a large number of investigations, in-situ and laboratory tests, etc., which are carried out in the field by the author. We know that the "5∙12" Wenchuan Earthquake in 2008 triggered strong ruptures and damages of massif, and destructed the concrete facing of the Zipinpu rock-fill dam in Minjiang River, which is very close to the earthquake source and sufferd a 0.56g' seismic acceleration. For this reason, this paper analyzes the possible damage on the Daliushu Dam site rock mass under the grouting in the future earthquake, returning to the present poor quality condition of rock mass, while this dam shares the seismic intensity, seismic acceleration, dam type and dam height similar to the Zipinpu Project. This paper puts forward a new research thought, which is the longtime -lasting strong earthquake,first causes the rupture of rock mass and the decrease of rock mass mechani cal parameters, and the lasting earthquake will then worsen the rock mass structure mechanics parameters, and even cause the large-scale massif damage. From this viewpoint, this paper, analyzes the stability of the dam foundation and abutment rock mass especially the stability of the thin massif of the right dam abutment by the numerical analysis. The analysis show that under the normal and the earthquake conditions (excluding the rock mass damage and mechanical parameters decrese resulted from the lasting earthquake), The Daliushu Dam Site and the right dam abutment are still stable when the safety factor is assumed to be 0.802 under the lasting earthquake. In addition, the calculation results show that the stability is not enough.

scholarly journals Synthesis of Metal Organic Frameworks by Ball-Milling

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Cheng-An Tao ◽  
Jian-Fang Wang
Keyword(s):  
Ball Milling ◽  
Large Scale ◽  
Raw Materials ◽  
Metal Organic Frameworks ◽  
Research Topic ◽  
Mass Ratio ◽  
Time Consumption ◽  
Metal Organic ◽  
Short Time ◽  
Made In

Metal-organic frameworks (MOFs) have been used in adsorption, separation, catalysis, sensing, photo/electro/magnetics, and biomedical fields because of their unique periodic pore structure and excellent properties and have become a hot research topic in recent years. Ball milling is a method of small pollution, short time-consumption, and large-scale synthesis of MOFs. In recent years, many important advances have been made. In this paper, the influencing factors of MOFs synthesized by grinding were reviewed systematically from four aspects: auxiliary additives, metal sources, organic linkers, and reaction specific conditions (such as frequency, reaction time, and mass ratio of ball and raw materials). The prospect for the future development of the synthesis of MOFs by grinding was proposed.

In Situ Tests on Creep Behavior of Rock Mass with Joint or Shearing Zone in Foundation of Large-Scale Hydroelectric Projects

2004 ◽  
Vol 261-263 ◽  
pp. 1097-1102 ◽  
Author(s):  
Jian Liu ◽  
Xia Ting Feng ◽  
Xiu Li Ding ◽  
Huo Ming Zhou
Keyword(s):  
Rock Mass ◽  
Creep Behavior ◽  
Large Scale ◽  
Time Dependent ◽  
Three Gorges Project ◽  
Three Gorges ◽  
The Three Gorges ◽  
The Three Gorges Project

The time-dependent behavior of rock mass, which is generally governed by joints and shearing zones, is of great significance for engineering design and prediction of long-term deformation and stability. In situ creep test is a more effective method than laboratory test in characterizing the creep behavior of rock mass with joint or shearing zone due to the complexity of field conditions. A series of in situ creep tests on granite with joint at the shiplock area of the Three-Gorges Project and basalt with shearing zone at the right abutment of the Xiluodu Project were performed in this study. Based on the test results, the stress-displacement-time responses of the joints and basalt are analyzed, and their time-dependent constitutive model and model coefficients are given, which is crucial for the design to prevent the creep deformations of rock masses from causing the failure of the operation of the shiplock gate at the Three-Gorges Project and long-term stability of the Xiluodu arc dam.

scholarly journals Evolution Pattern and Matching Mode of Precursor Information about Water Inrush in a Karst Tunnel

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1579
Author(s):  
Jie Song ◽  
Diyang Chen ◽  
Jing Wang ◽  
Yufeng Bi ◽  
Shang Liu ◽  
...  
Keyword(s):  
Rock Mass ◽  
Stress Field ◽  
Displacement Field ◽  
Water Inrush ◽  
Seepage Field ◽  
Karst Tunnel ◽  
Rock Mass Structure ◽  
Evolution Pattern ◽  
Water Blocking ◽  
Precursor Information

The water inrush of the Shangjiawan karst tunnel is used to study the evolution pattern of precursor water inrush information in water-filled caves and to further reveal the matching mode of the information. The three-dimensional numerical method FLAC3D was used to simulate the evolution process of water inrush after damage to a water-blocking rock mass structure in a water-filled cave and to obtain the evolution pattern of precursor water-inrush information caused by the damage. The results show that the multifield response to the characteristic precursor information of the water-inrush pattern after the fracture of the water-blocking rock mass follows the order of stress-field displacement-field seepage-field. Further, the matching pattern of the information shows that the stress field increased first and then decreased, the displacement field always increased, and the seepage field increased first and then decreased.

scholarly journals Learning As It Happens: A Decade of Analyzing and Shaping a Large-Scale Online Learning System

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Matthieu J. S. Brinkhuis ◽  
Alexander O. Savi ◽  
Abe D. Hofman ◽  
Frederik Coomans ◽  
Han L. J. Van der Maas ◽  
...  
Keyword(s):  
Online Learning ◽  
Large Scale ◽  
Response Times ◽  
Learning System ◽  
Learning Gains ◽  
Online Experimentation ◽  
Quality Of Fit ◽  
Item Reliability ◽  
Made In

With the advent of computers in education, and the ample availability of online learning and practice environments, enormous amounts of data on learning become available. The purpose of this paper is to present a decade of experience with analyzing and improving an online practice environment for math, which has thus far recorded over a billion responses. We present the methods we use to both steer and analyze this system in real-time, using scoring rules on accuracy and response times, a tailored rating system to provide both learners and items with current ability and difficulty ratings, and an adaptive engine that matches learners to items. Moreover, we explore the quality of fit by means of prediction accuracy and parallel item reliability. Limitations and pitfalls are discussed by diagnosing sources of misfit, like violations of unidimensionality and unforeseen dynamics. Finally, directions for development are discussed, including embedded learning analytics and a focus on online experimentation to evaluate both the system itself and the users’ learning gains. Though many challenges remain open, we believe that large steps have been made in providing methods to efficiently manage and research educational big data from a massive online learning system.

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