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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Korean Tunnelling and Underground Space Association
Journal Basic Information
Journal DOI :
Korean Tunnelling and Underground Space Association (KTA)
Editor in Chief :
Volume & Issues
Volume 14, Issue 6 - Nov 2012
Volume 14, Issue 5 - Sep 2012
Volume 14, Issue 4 - Jul 2012
Volume 14, Issue 3 - May 2012
Volume 14, Issue 2 - Mar 2012
Volume 14, Issue 1 - Jan 2012
Selecting the target year
A case study on excessive displacements occurred in the tunnels caused by rainfall
Kim, Nag-Young ; Kim, Hong-Jong ; Oh, Young-Seok ; Kim, Chang-Yong ; Yang, Tae-Sun ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 561~573
DOI : 10.9711/KTAJ.2012.14.6.561
Recently, tunnel constructions have been increased in Korea. According to the increment of tunnel constructions, cases of tunnel collapses also have been increased under tunnel construction. Among these tunnel collapses, after a certain amount of time has elapsed due to excessive displacements on slope of tunnel exit or entrance, cases of tunnel collapse have been increased rapidly. Therefore, the case study was conducted in this study to figure out factors effect on the tunnel collapses due to excessive displacements on tunnel exit or entrance slopes. Base on the case study, the fragmental zone of fault and the rainfall were most important factors on the collapse.
Numerical simulation for variations of water saturation in bentonite buffer under the effect of a rock joint using the TOUGH2 code
Kim, Jin-Seop ; Cho, Won-Jin ; Lee, Kyung-Soo ; Choi, Heui-Joo ; Cho, Gye-Chun ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 575~593
DOI : 10.9711/KTAJ.2012.14.6.575
This paper briefly introduces the scope and objectives of SKB Task 8, which is an international cooperative research project. In addition, the hydraulic behaviors of bentonite buffer focusing on the interactions between bentonite and a rock mass with a joint were investigated using TOUGH2 code as part of a sub-mission of Task 8a. The effects of a rock joint and high capillary pressure of bentonite on the re-saturation properties and pressure distribution in a buffer were identified and successfully incorporated in the TOUGH2 code. Based on the numerical results, it was found that the speed of re-saturation in bentonite surrounded by a rock mass with a joint is 2.5 to 12 times faster than that in a condition without a rock joint, while the degree of saturation in the lower part of the buffer material is generally higher than in the upper part in both the cases of with and without a joint. It can be anticipated that the results obtained from this study can be applied to an estimation of the full saturation time and a determination of optimum thickness with regard to the design of the bentonite buffer in a high level waste disposal system.
Study on mechanical behavioral characteristics of FRP-concrete composit member considering interface element between FRP and concrete
Lee, Gyu-Phil ; Park, Young-Taek ; Hwang, Jae-Hong ; Kim, Dong-Gyou ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 595~606
DOI : 10.9711/KTAJ.2012.14.6.595
Utilization of fiber reinforced polymer(FRP) material has been increased to solve construction material problems such as corrosion, etc. However, there are still many problems in using a linear-shaped FRP material for a tunnel structure with curved section. In this study, the loading tests were performed on the curved FRP-concrete composite material to evaluate its behavior as tunnel support. These tests were based on the result from preliminary numerical analysis on FRP-concrete composite material. Also, additional numerical analysis considering interface characteristics between FRP and cement-concrete was conducted to compare the result of loading test on FRP-concrete composite material. From the results of the loading test and numerical analysis, the analysis method suggested from this study is reasonable to evaluate the mechanical behavior of FRP-concrete composite material.
Prediction of spatial distribution of air pollutants within tunnel
Park, Il-Gun ; Hong, Min-Sun ; Kim, Beom-Seok ; Kang, Ho-Geun ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 607~616
DOI : 10.9711/KTAJ.2012.14.6.607
The need for management of tunnel air quality is imminent considering the rapid increase of number and span of tunnels in Korea. To investigate spatial distribution of
were measured and model simulations were performed in Namsan 1 tunnel. Results show that
concentrations were 250 ppm to 400 ppm higher in the exit than tunnel entrance. Also,
concentrations were 200 ppm to 300 ppm lower inside no ventilating vehicle than in the tunnel. Both experimental and model simulation results show that spatial distribution and concentration gradient of air pollutant inside tunnel are highly dependent on traffic density.
A study on the correlation between the rock mass permeability before and after grouting & injection volume and the parameters of Q system in a jointed rock mass tunnel
You, Kwang-Ho ; Jie, Hong-Keun ; Seo, Kyoung-Won ; Kim, Su-Jeong ; You, Dong-Woo ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 617~635
DOI : 10.9711/KTAJ.2012.14.6.617
In this study, correlations between the rock mass permeability before and after grouting & injection volume and the parameters of Q system were investigated on a grouted rock mass tunnel corresponding to rock class 4 and 5 in terms of Q classification system. As a result, it appears that the lower the Q value is, the higher the before-grouting permeability becomes and the smaller the injection volume of grouting becomes. Also RQD and Jn are the most influencing factors to the permeability of rock mass and the injection volume of grouting. In addition, it turned out that it was very difficult to lower the permeability of rock mass smaller than
m/sec with the ordinary portland cement grout.
Section enlargement by reinforcement of shotcrete lining on the side wall of operating road tunnel
Kim, Dong-Gyou ; Shin, Young-Wan ; Shin, Young-Suk ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 637~652
DOI : 10.9711/KTAJ.2012.14.6.637
The protector with the shape of '
' in cross section can be set up in the tunnel, which can be constructed for enlargement of cross section, to keep traffic flow in the tunnel. It is impossible to install the rockbolt in the side wall of tunnel due to a limited space between the protector and cutting surface of side wall. The objective of this study is to suggest the optimum thickness of shotcrete lining without rockbolt on the side wall and to evaluate the stability of tunnel enlarged. Numerical analysis was performed to evaluate the displacement at the center of tunnel, the convergence of tunnel, and the stress in shotcrete lining in 4-lane NATM road tunnel enlarged from 3-lane NATM road tunnel. The vertical displacement at the center of tunnel and the convergence of crown in the tunnel with rockbolt in the side wall were almost similar to those in the tunnel without rockbolt in the side wall. The convergence of bench/invert and the stress in shotcrete lining without rockbolt on the side wall were greater maximum 0.57 mm and 1,300 kN/
than those with rockbolt in the side wall. The increased convergence and the stress in shotcrete lining can be reduced in incerasing of thickness of shotcrete lining about 20% (5 cm) of standard thickness, 25 cm, of shotcrete lining.
A study on damage mechanism of transition section in cut and cover tunnel using 3 dimensional numerical analysis
Park, Jae-Young ; Son, Jeong-Hun ; Park, Kwang-Lim ; Oh, Young-Seok ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 653~666
DOI : 10.9711/KTAJ.2012.14.6.653
This study made progress about Demage Mechanism of Transition Section in Cut and Cover Tunnel. For this study, Inspection and test was carried out about Transition Section. After this process, Numerical Analysis was accomplished by 2D, 3D. A result of inspection and test, It couldn't find the reason why the upper slab Demage was detected. So 2D Numerical Analysis was conducted. It was analyzed that the Safety Factor(1.0) was satisfied in 2D. But, the result of 3D Numerical Analysis, The reason was found that the Demage on upper slab was caused by moment change. The Moment was changed by column interval transition. For Retrofitting, Column was added under slab in tunnel. It was found that the addition column decreased upper slab deformation. After this study, It could be find that are important 3D Numerical Analysis as well as 2D Numerical Analysis in case of Transition Section. This Study can help developing construction and maintenance about Tunnel. Finally, It's going to study Retrofitting plans which have minimum influence of Transition Section in Cut and Cover Tunnel.
Risk management applicable to shield TBM tunnel: I. Risk factor analysis
Hyun, Ki-Chang ; Min, Sang-Yoon ; Moon, Joon-Bai ; Jeong, Gyeong-Hwan ; Lee, In-Mo ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 667~681
DOI : 10.9711/KTAJ.2012.14.6.667
In general, risk management consists of a series of processes or steps including risk identification, risk analysis, risk evaluation, risk mitigation measures, and risk re-evaluation. In this paper, potential risk factors that occur in shield TBM tunnels were investigated based on many previous case studies and questionaries to tunnel experts. The risk factors were classified as geological, design or construction management features. Fault Tree was set up by dividing all feasible risks into four groups that associated with: cutter; machine confinement; mucking (driving) and segments. From the Fault Tree Analysis (FTA), 12 risk items were identified and the probability of failure of each chosen risk item was obtained.
Risk management applicable to shield TBM tunnel: II. Risk analysis methodology
Hyun, Ki-Chang ; Min, Sang-Yoon ; Moon, Joon-Bai ; Jeong, Gyeong-Hwan ; Lee, In-Mo ;
Journal of Korean Tunnelling and Underground Space Association, volume 14, issue 6, 2012, Pages 683~697
DOI : 10.9711/KTAJ.2012.14.6.683
In this paper, a risk analysis methodology applicable to shield TBM tunnels was studied. Fault Tree Analysis (FTA) was utilized to identify all risk items and to calculate the probability of failure of each item and Analytic Hierarchy Process (AHP) was used to obtain the impact of each risk item. Finally, a risk level of each risk item can be assessed. Developed methodology is applied to a Seoul subway site in which EPB shield tunnel method was utilized and it was found that risk analysis results matched reasonably well with field data.