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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Tunnel and Underground Space
Journal Basic Information
Journal DOI :
Korean Society for Rock Mechanics
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Volume & Issues
Volume 19, Issue 6 - Dec 2009
Volume 19, Issue 5 - Oct 2009
Volume 19, Issue 4 - Aug 2009
Volume 19, Issue 3 - Jun 2009
Volume 19, Issue 2 - Apr 2009
Volume 19, Issue 1 - Feb 2009
Selecting the target year
Visualization and Optimization of Construction Schedule Considering the Geological Conditions in the Complicated Underground Cavern
Choi, Yong-Kun ; Park, Joon-Young ; Lee, Sung-Am ; Kim, Ho-Yeong ; Lee, Hee-Suk ; Lee, Seung-Cheol ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 167~173
Underground storage cavern is known as the most complicated underground project because of the complexity of construction schedule, tunnel size, and geological problems. In order to optimize the construction schedule of underground storage cavern, two up-to-date technologies were applied. The first technology was 3 dimensional visualization of complicated underground structures, and the second was 4 dimensional simulation considering construction resources, geological conditions and construction schedule. This application case shows that we can achieve optimized construction schedule in the ways to optimize the number of work teams, fleets, the sequence of tunnel excavation, the commencement time of excavation and the hauling route of materials and excavated rocks. 3 dimensional modeling can help designer being able to understand the status of complicated underground structures and to investigate the geological data in the exact 3 dimensional space. Moreover, using 4 dimensional simulation, designer is able to determine the bottle neck point which appear during hauling of excavated rocks and to investigate the daily fluctuation in cost.
SEISMIC MONITORING IN SURFACE MINES
Ajay Kumar, L. ; David Raj, D. Edwin ; Renaldy, T. Amrith ; Vinoth, S. ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 174~180
This paper gives a brief review of seismicity and seismic monitoring in surface mines. A summary of various researches related to seismicity is presented. Our research focuses on the understanding of seismicity and the application of analytical techniques to seismicity. Seismic monitoring plays an important role in the identification of potential failure planes and thereby predict potential failures. Much of the instrumentation used in our research is derived from earthquake monitoring systems. The major aspects in seismic monitoring are an instrumentation used, size of the network and data acquisition systems. Seismic monitoring in surface mines could be successfully applied to the improvement of safety standards in slope stability.
Support Characteristics of Rock Bolt and Spiral Bolt
Cho, Young-Dong ; Song, Myung-Kyu ; Lee, Chung-Shin ; Kang, Choo-Won ; Ko, Jin-Seok ; Kang, Seong-Seung ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 181~189
This study is to evaluate an effect of supports with respect to these supports after comparing the characteristic of support between rock bolt of a widely used type and spiral bolt of a new type. For these purposes, we performed pull-out test in laboratory about rock and spiral bolts in the case of cement-mortar grout curing periods, 7 and 28 days, then calculated pull-out load, displacement, external pressure, inner pressure and shear stress using data obtained from the results of pull-out test, respectively. In relation between pull-out load and displacement, displacement of spiral bolt is larger than one of rock bolt. It is considered that mechanical property of rock bolt is due to larger than one of spiral bolt. In addition, displacement of supports shows nearly same or decreasing with curing periods. We found that because adhesive force between supports and cement-mortar grout is increasing with compressive strength of grout according to curing periods. The inner pressure of spiral bolt is represented larger than one of rock bolt at a step of same pull-out load. It is suggested that spiral bolt is more stable than rock bolt, maintaining stability of ground or rock mass, when supports are installed in a ground or rock mass under the same condition. Putting together with above results, we can consider that spiral bolt as a new support on an aspect of pull-out load and inner pressure is larger than rock bolt in a ground or rock mass under the same condition. Moreover, spiral bolt is more effective support than rock bolt, considering an economical and constructive aspects of supports, as well as ground or rock stability before or after installing supports.
Simulation of Blasting Demolition of Reinforced Concrete Structures and Ground Vibration using Finite Element Method
Choi, Joo-Hee ; Jung, Jae-Woong ; Jeon, Seok-Won ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 190~202
With the increasing demand for blasting demolition in urban areas, the simulation of structural collapse prior to the real blasting operation is a key process for ensuring the success and safety of the blasting demolition. The simulation of collapsing behavior of a structure is not only vital for preventing unexpected economic loss and casualties, but also helpful in minimizing public claims by precisely estimating the environmental impact resulting from the operation. This study proposes a new technique for simulation of a blast demolition using FEM based LS-DYNA codes. The technique tries to simplify the complex arrangement of reinforcing bars, and use the actual properties of the concrete and steel reinforcing bars, thereby improving the overall capability of the simulation to match well with the collapsing behavior of real-scale structures.
A Sensitivity Analysis of Design Parameters of an Underground Radioactive Waste Repository Using a Backpropagation Neural Network
Kwon, S. ; Cho, W.J. ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 203~212
The prediction of near field behavior around an underground high-level radioactive waste repository is important for the repository design as well as the safety assessment. In this study, a sensitivity analysis for seven parameters consisted of design parameters and material properties was carried out using a three-dimensional finite difference code. From the sensitivity analysis, it was found that the effects of borehole spacing, tunnel spacing, cooling time and rock thermal conductivity were more significant than the other parameters. For getting a statistical distribution of buffer and rock temperatures around the repository, an artificial neural network, backpropagation, was applied. The reliability of the trained neural network was tested with the cases with randomly chosen input parameters. When the parameter variation is within
, the prediction from the network was found to be reliable with about a 1% error. It was possible to calculate the temperature distribution for many cases quickly with the trained neural network. The buffer and rock temperatures showed a normal distribution with means of
standard deviations of
, respectively. Using the neural network, it was also possible to estimate the required change in design parameters for reducing the buffer and rock temperatures for
Variation of Geomechanical Characteristics of Granite and Orthogneiss in Wonju Area due to Accelerated Artificial Chemical Weathering Tests
Woo, Ik ; Um, Jeong-Gi ; Park, Hyuck-Jin ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 213~225
The purpose of the study is to evaluate the effects of chemical weathering on the granite and orthogneiss in Wonju area based on accelerated artificial chemical weathering. The rock samples were scrutinized the variation of index properties and ion exchanges caused by artificial chemical weathering which was implemented with leaching test for 170 days using double soxhlet extractor. The differential weathering and decrease of p wave velocity were obtained by weathering process without significant changes of porosity. In case of granite samples, the uniaxial compression strength was reduced by 20% and 16% for the F-grade and SW-grade, respectively. For MW-grade granite, however, was not able to examine the effect of strength reduction due to lack of sample number. Also, for orthogneiss, it is difficult to compare the values of uniaxial compressive strength between before and after the test because of its strong anisotropy.
A Study on the Natural Ventilation Force in Tunnels
Lee, Chang-Woo ; Park, Hong-Chae ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 226~235
Force induced by the natural ventilation in tunnel is likely to generate adverse influences on the airflow during the normal operation and create even more unfavorable circumstances during the tunnel fire. The influence of the natural ventilation is required to take into account in designing and operating the ventilation as well as safety systems. The magnitude of natural ventilation force depends on a variety of factors associated with the topographical, meteorological and physical features of tunnel. Unfortunately, at this moment those are difficult to quantify and none of the countries has suggested its estimation method in the design guideline. This study aims at quantifying the natural ventilation force at a local highway tunnel by three different methods. The first method employes direct measurement of the pressure at portals, while the second applies a stepwise approach to eliminate the piston effect ahead of deriving the natural ventilation force and the third method uses the concept of barometric barrier.
Evaluation of Cave-in Possibility of a Shallow Depth Rock Tunnel by Rock Engineering Systems and Uumerical Analyses
Kim, Man-Kwang ; Yoo, Young-Il ; Song, Jae-Joon ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 236~247
Overpopulation has significantly increased the use of underground spaces in urban areas, and led to the developments of shallow-depth underground space. Due to unexpected rock fall, however, it is very necessary to understand and categorize the rock mass behaviors prior to the tunnel excavation, by which unnecessary casualties and economic loss could be prevented. In case of cave-in, special attention should be drawn since it occurs faster and greater in magnitude compared to rock fall and plastic deformation. Types of cave-in behavior are explained and categorized using seven parameters - Uniaxial Compressive Strength (UCS), Rock Quality Designation (RQD), joint surface condition, in-situ stress condition, ground water condition, earthquake & ground vibration, tunnel span. This study eventually introduces a new index called Cave-in Behavior Index (CBI) which explains the behavior of cave-in under given in-situ conditions expressed by the seven parameters. In order to assess the mutual interactions of the seven parameters and to evaluate the weighting factors for all the interactions, survey data of the experts' opinions and Rock Engineering Systems (RES) were used due to lack of field observations. CBI was applied to the tunnel site of Seoul Metro Line No. 9. UDEC analyses on 288 cases were done and occurrences of cave-in in every simulation were examined. Analyses on the results of 288 cases of simulations revealed that the average CBI for the cases when cave-in for different patterns of tunnel support was estimated by a logistic regression analysis.
Field Tests and Analysis of Groundwater System for Stabilization of Slope in Large Open-Pit Coal Mine
Ryu, D.W. ; Kim, H.M. ; Oh, J.H. ; Sunwoo, C. ; Jung, Y.B. ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 248~260
With regard to oversea mineral resources development, recent trend has been changed from a simple capital investment to a direct development of the resources. In relation to the stability of a slope in large open-pit coal mine, groundwater system was investigated and the validity of horizontal drainage hole was evaluated in Pasir coal mine, Indonesia. In this work, various field tests were carried out for a characterization of groundwater system, which included in-situ permeability measurement, tracer test and monitoring of groundwater levels. Especially, the influence of SM river on the characteristics of the groundwater flow system was mainly inspected. For the permeability measurement, Guelph permeameter was employed, and was found that sandstone was more permeable than mudstone and coal seam. From a comparison of lithological structure and the results of groundwater level monitoring, sandstone and thin coal seam with fractures were found to be a main channel for groundwater flow. In the results of tracer tests, the effect of SM river on the groundwater system depends on the geological structure of its base. To identify the effect of horizontal drainage holes, 2-D groundwater modeling was performed. Four different cases were tested, which are different from the length of drainage hole and the existence of pond on top of the slope. To enhance the drainage effect and slope stability, the drainage hole should be drilled to the depth of coal seam layer, which provides a main pathway of groundwater flow and embedded by sandstone. For this purpose, correct identification of surrounding geology should be preceded.
Report of participation in SINOROCK 2009, Hong Kong, China
Nan, Zhang ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 261~265
Report of Participation in the 3rd International Conference on New Development in Rock Mechanics and Engineering Sanya, P.R.China, May 24-26, 2009
Nan, Zhang ;
Tunnel and Underground Space, volume 19, issue 3, 2009, Pages 266~268