Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Energy
Prediction of Rockburst Classification by SVM Method
Aibing, Li (University of Technology, Changsha Institute of Mining Research) | Guang, Zhang (Changsha Institute of Mining Research) | Peiliang, Hu (University of Technology) | Zhengyu, Liu (University of Technology) | Yanbo, Yin (University of Technology) | Ping, Zhou (University of Technology)
ABSTRACT Rockburst is a spontaneous, violent fracture of rock that can occur in deep mines. The research of rockburst has for many years and not yet for satisfactory answers. Based on the data of rockburst cases, and take to mining depth, ratio of the maximum tangential stress of surrounding rock and uniaxial compressive strength of rock, ratio of uniaxial compressive strength and tensile strength of rock and impact propensity score of rock as for the main factors or the four criterion indexes to distinguish of rockburst whether happened, and a predication model of rockburst by the SVM method was carried out. By the verified of the Dongguashan Mine case study, it is showed this method is feasible.
- Geology > Rock Type (0.97)
- Geology > Geological Subdiscipline > Geomechanics (0.97)
- Geology > Structural Geology (0.69)
- Materials > Metals & Mining (1.00)
- Energy (0.74)
ABSTRACT The west express way which links between Yanpyong-Dong and Doksan-Dong, the west area of Seoul, South Korea has been notorious for extremely heavy traffic area since its first opening in 1991 (i.e. the average vehicle speed is less than 25km/h, a daily traffic is 112,000 and among them, more than 94% of the vehicles are the light vehicles). Hence, the city government recently initiated a new underground BTO (Build-Transfer-Operate) road project for releasing heavy traffic and a high construction cost. he proposed underground express road being designed is the first double-level tunnel ever designed in South Korea and using Drill & Blast excavation method. A total length of tunnel for light vehicles is 10.91km long including both open cut and tunnel sections and 4 ventilation shafts. Many design issues had been aroused during the preliminary design phase (i.e. a detail design is currently working on). This paper discusses design focuses including excavation methods, ground water issues, a deck slab installation, and a construction cost etc. for the double-level road tunnel design in urban area.
- Construction & Engineering (1.00)
- Transportation > Ground > Road (0.71)
- Energy > Oil & Gas > Upstream (0.68)
Numerical Analysis of Rock Particle Flow Around a Top-Hammer Drill Bit
Song, Chang-Heon (Korea Institute of Industrial Technology) | Kwon, Ki-Beom (Korea Institute of Industrial Technology) | Park, Jin-Yeong (Korea Institute of Industrial Technology) | Shin, Dae-Yeong (Korea Institute of Industrial Technology) | Cho, Jung-Woo (Korea Institute of Industrial Technology)
ABSTRACT This study focuses on a series of CFD (computational fluid dynamics) simulations that enable the optimization of drill bit design by assessing internal rock particle and air flow paths. We used the Star-CCM+ code to simulate the multi-phase flow (i.e., rock particle discharge by flushing air during drilling) with input parameters obtained from the in situ drilling tests. Three design factors were determined, with a Taguchi experimental design method utilized to evaluate optimum values for each factor.
- Reservoir Description and Dynamics (1.00)
- Well Drilling > Drill Bits > Bit design (0.56)
Comparison of Cutting Forces for V-Type Disc Cutter and Performance Prediction of TBM Using Portable Linear Rock Cutting Machine (PLCM)
Tumac, D. (Istanbul Technical University) | Balci, C. (Istanbul Technical University) | Bilgin, N. (Istanbul Technical University) | Copur, H. (Istanbul Technical University)
ABSTRACT The usage of full face tunnel boring machines (TBMs) for mining and civil projects are increasing enormously in recent years. Selection of TBM for a given rock formation is very important for the success of the project. A great care must be taken for machine selection and performance prediction in the project design phase. Full scale linear rock cutting test (LCM) and University of Trondheim performance prediction model are widely accepted methods for the performance prediction of the full face tunnel boring machines. For the performance prediction of TBMs, a portable linear rock cutting machine (PLCM)โข using mini discs is developed by the members of Istanbul Technical University (ITU), Mining Engineering Department. In this study, the intact rock sample, arcose is obtained along the tunnel alignment. The physical and mechanical properties of the rock sample are determined according to ISRM and ASTM standards. Big rock block sample is subjected to full scale linear rock cutting tests with different depth of cut and cutter spacing using 15'' (380 mm in diameter) V-type disc cutters. These rock samples are also subjected to portable linear rock cutting tests using mini V-type (130 mm in diameter) disc cutter at 5 mm depth of cut. Rock cutting test results from LCM and PLCM tests are compared with each other. These studies indicated that portable linear rock cutting test can be used with a statistical reliability for selection of TBMs and prediction of their performance.
- North America > United States (0.46)
- Asia > Middle East > Turkey > Istanbul Province > Istanbul (0.27)
- Europe > Norway > Trรธndelag > Trondheim (0.24)
Challenges of Design and Construction of a Highway Tunnel through Mixed Geology in Himalayas
Goel, R.K. (Central Institute of Mining & Fuel Research) | Dwivedi, R.D. (Central Institute of Mining & Fuel Research) | Viswanathan, G. (Chenani-Nashri Tunnelway Ltd) | Rathore, J.S. (Chenani-Nashri Tunnelway Ltd)
ABSTRACT The Government of India has entrusted the National Highway Authority of India (NHAI) with the responsibility of four laning of Chenani to Nashri Section of NH-1A from km 89.00 to km 130.00 including 9km long bi-directional traffic tunnel with a parallel escape tunnel of 9km on BOT (annuity) basis. The project area lies in western Himalayan region. The rock masses along the project of the Chenani-Nashri tunnel, belong to the Lower Murree formation that includes a sequence of interbedded sandstones, siltstones and claystones layers. The tunnel behaviour classification of the rock mass has been performed by Geodata, Italy. These rock behaviour classes has been correlated with the rock mass behavior type of NATM. The supports for various behavior classes have also been designed using the numerical methods as per the requirements. The tunnel construction work was started in August 2011 from South end and in September 2011 from North end. As expected the experience of tunneling in Himalayan mixed geology having bands of sandstone, siltstone, claystone, intermingled siltstone and claystone and sheared siltstone and claystone is not very encouraging. There have been instances of overbreaks and cracks in shotcrete support in the tunnel. Accordingly the designs have been modified. The benefits of displacements/convergence monitoring have been highlighted at the end.
- Energy > Oil & Gas > Upstream (0.68)
- Government > Regional Government > Asia Government > India Government (0.54)
SYNOPSIS Spalling is the common mode of failure in deep tunnels excavated in strong rocks which results in notches around the tunnel boundary. Recent developments in the analysis of spalling failure have resulted in the empirical Hoek-Brown spalling criterion which is used for prediction of spalling profile. However, this criterion is commonly applied following elastic numerical analyses and in an implicit way. In this paper, an explicit solution is derived for spalling profile around circular tunnels. The stress distribution around tunnel is obtained using the well known analytical elastic solution, and then the locus of points which satisfy the empirical Hoek-Brown spalling criterion is determined. The derived polar function is used for graphical illustration of the effect of governing parameters on the spalling profile. Finally, the results obtained from the solution are compared with observations made in real tunnels. Showing good agreement with in-situ measurements as well as having explicit and easy-to-use form, the derived solution is expected to be extensively used in the future for prediction of spalling profile around circular tunnels.
ABSTRACT Since the establishment of the International Society for Rock Mechanics (ISRM) in the 1960s, there have been important scientific developments and technological advances both in rock mechanics and rock engineering. Particularly, modeling of rock behaviour, design methodologies for rock structures and rock testing methods are the main issues in these developments and advances. The models developed depend considerably on the input parameters such as boundary conditions and material and rock mass properties. For this reason, establishing how to obtain these input parameters for a particular site, rock mass and project is important. Accordingly, since 1974, the ISRM Commission on Testing Methods has spent considerable effort in developing a succession of Suggested Methods (SMs) for different aspects of rock mechanics with the contribution of a number of working groups. The SMs are intended as guidance, explaining the recommended procedures to follow in the works associated with the various aspects of rock mechanics, such as rock characterisation, testing and monitoring. In this paper; the past, present and future of laboratory and in-situ rock testing and monitoring techniques and then the general principles followed in developing the ISRM SMs, stages in their evaluation and the recent developments related to the SMs are briefly given.
- North America > United States (1.00)
- Europe (1.00)
- Asia > Middle East > Turkey (0.29)
- Africa > Middle East > Egypt (0.29)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.68)
- Materials > Metals & Mining (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Energy > Power Industry (0.67)
ABSTRACT In Korea, stockpiling capacity of hydrocarbon products has been steadily increased since 1980. Currently, Korea has storage capacity equal to about 146 million barrels, and approximately 73 percent of the total, 107.3 million barrels, were stored in underground space. Underground storage facilities have advantages over aboveground tanks in terms of the cost of construction, operation and maintenance as well as safety, security and environmental acceptability. The key technologies in the underground storage of hydrocarbon products are the construction of large rock cavern with crosssectional area ranging from 300 up to 520 m2, the long-term structural stability of the cavern and the full containment of the product in rock caverns. Based on 33-year experience in design, construction and operation of underground storage facilities, Korea has accumulated technical expertise in this field and achieved the position as one of the model countries holding stockpiles of strategic oil reserves.
- Energy > Oil & Gas > Upstream (1.00)
- Energy > Oil & Gas > Downstream (1.00)
ABSTRACT We generalize our view of a bonded-particle model (BPM) to consist of a base material (of rigid grains joined by deformable and breakable cement at grain-grain contacts) to which larger-scale joints can be added and whose mechanical behavior is simulated by the distinct-element method using the two- and three-dimensional discontinuum programs PFC2D and PFC3D. The micromechanical processes that control brittle fracture and thus, should inform any micromechanical model, are summarized. The rich variety of microstructural models that can be produced by the bonded-particle modeling methodology are described and classified with respect to their microstructural and larger-scale features. These models provide a wide range of rock behaviors that encompass both compact and porous rock at both an intact and rock-mass scale, and examples are provided of how BPMs are being used to model rock at these scales. The examples include an intact anisotropic material that may swell and contract in response to changes in saturation, the behavior of two alternative BPMs that can match both the uniaxial and tensile strengths of compact rock and the embedding of an intact BPM within a larger continuum model to study fracturing around a gold-mine stope in quartzite.
- North America > United States (1.00)
- Europe (1.00)
- Asia (0.67)
- North America > Canada (0.67)
- Geology > Rock Type (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Structural Geology (0.92)
- Geology > Mineral (0.88)
ABSTRACT Based on a series of laboratory tests and in situ monitoring and tests at deep tunnels excavated by TBM or D&B method, mechanism of evolution process of different types of rockburst, including strain burst, strain-structure slip rockburst, immediate rockburst and time delayed rockburst, and has been understood. The digital borehole televiewer and seismicity monitoring system have been used to obverse cracking initiation and propagation process during rock burst evolution process. A warning system based on micro seismicity has been established for warning of various intensities of rockbursts, such as slight, moderate, intensive and extremely intensive rockbursts. The probability with the intensity of rockburst is also given. The strategy for excavation and support design has been recommended for various intensities of rokcburst before the excavation. The strategy for dynamic control of rockburst evolution process is also proposed according the warning. The methodology has been successfully applied to rockburst risk reduction for deep tunnels at Jinping II hydropower station. The results have illustrated applicability of the proposed methodology and techniques on rockburst.