• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.1302-1313
• /
• 2010

The west express way is notorious for extremely heavy traffic area in the west of Seoul, South Korea. Hence, the city government recently initiated a new underground BTO (Build-Transfer-Operate) road project to solve traffic congestion and a high construction cost. The proposed underground express road being designed is the first double-level tunnel ever designed in South Korea and using Conventional tunnelling method (NATM). A total length of tunnel for light vehicles is 10.91km long including both open cut structures and concrete lining with middle-deck in bored tunnel. There are also 4 ventilation shafts for ventilation and evacuation on emergency. Many design issues had been aroused during the preliminary design phase and detail design phase is currently going 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 of urban area.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.1314-1321
• /
• 2010

The west express way which links south west area of the central city of Seoul has been notorious for extremely heavy traffics 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). The city government recently initiated a new BTO(Build-Transfer-Operate) project as an alternative in releasing heavy traffic and a high construction cost. The proposed underground express road is the first double-level tunnel (i.e. a total length of road is 10,91km and the tunnel is 9.308km long) ever built in South Korea, while such tunnel system is not new worldwide as such A86 East tunnel in France, SMART tunnel in Malaysia, and Fuxing tunnel in China. This paper discusses major design issues regarding the internal structures such as deck slab, and secondary liner.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.1
• /
• pp.155-166
• /
• 2019

It is necessary to construct underground in the metropolis. Road traffic has reached saturation point. The city has several underground road construction projects. In abroad, double deck tunnels are planned and constructed. It is attained a high level of underground development technology. In case the double deck tunnel (2 lane) is planed instead of the bidirectional tunnel (2 lane), excavation area is similar. But tunnel width is decreased. The reduced width can cut cost for the tunnel reinforcement. This study evaluates the stability of excavation on double deck tunnel. By the assessment of the strength-stress ratio and strength reduction method, quantitative analysis is conducted between double deck tunnel and the bidirectional tunnel.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.4
• /
• pp.337-346
• /
• 2020

Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

• Explosives and Blasting
• /
• v.20 no.3
• /
• pp.59-71
• /
• 2002

The points of this design case are the planning and excavation method of a new double-tracked railroad tunnel which is approx. 11∼22 meters apart from existing single-tracked railroad tunnel. For the optimum excavation method some needs are required in design stage, such as the reduction of noise and vibration, public resentment, damage of buildings and construction costs. Hence the estimation and application of allowable noise and vibration criterion is important. The ground coefficient (K, n) of this site is determined by field trial blasting. The excavation method is chosen to satisfy the allowable noise and vibration criterion. In addition, in order to ensure the stability of existing single-tracked railroad tunnel, the instrumentation of maintenance level is accompanied during the construction stage. As a result of this design condition, central diaphragm excavation with line drilling and pre-large hole boring blasting is applied to the area within 15 meters apart from existing tunnel. And above 15 meters apart, pre-large hole boring blasting is designed.

• Journal of Chest Surgery
• /
• v.12 no.2
• /
• pp.119-126
• /
• 1979

This is one case report of the extremely rare congenital cardiac malformation, Double-outlet of left ventricle in corrected transposition of great arteries. 11-year-old boy complained acrocyanosis and exertional dyspnea, the parents noticed cyanosis since birth. Physical examination revealed acrocyanosis, clubbed fingers and toes, G-III pansystolic murmur on 2nd and 3rd ICS, LSB. Right heart catheterization revealed significant $O_2$ jump in ventricular level. Right and left ventriculography showed the both catheters arriving in the same ventricle i.e. anterior chamber, morphological left ventricle was in right and anterior position, simultaneous visualization of aorta and pulmonary artery and aorta locating anterior and right side of pulmonary artery. Echo cardiogram surely disclosed interventricular septum. Conclusively it was clarified that the patient has Double-outlet of left ventricle and corrected transposition of great arteries [S.L.D.]. Operation was performed to correct the anomalies under extracorporeal circulation with intermittent moderate hypothermia. Right-sided ventriculotomy disclosed the following findings. 1. Right-sided ventricle was morphological left ventricle. 2. Left-sided ventricle was morphological right ventricle. 3. Right side atrioventricular valve was bicuspid. 4. Left side atrioventricular valve was tricuspid. 5. Aortic valve was superior, anterior and right side of pulmonary valve. 6. Subpulmonary membranous stenosis. 7. Non-committed ventricular septal defect. We made a tunnel between VSD and aorta with Teflon patch so that arterial blood comes through VSD and the tunnel into aorta. After correction the patient needed assisted circulation for 135 min. to have adequate blood pressure. Postoperatively by any means, adequate blood pressure could not be maintained and expired in the evening of operation day.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.6
• /
• pp.581-591
• /
• 2016

Several attempts to construct multi-purpose tunnel for both road and waterway have been made. The multi-purpose tunnel is mainly used as a road tunnel, however it is transferred to waterway to control flood during rainy season. The planning of the multi-purpose tunnel is recognized as cost-effective way of infrastructure construction. In case of the multi-purpose tunnel constructed beneath groundwater table, seasonal fluctuation of groundwater table and repeated flow in the tunnel may cause long-term deterioration of the tunnel system. In this study, the behavior of multi-purpose tunnel in view of groundwater table or flow in the tunnel is investigated using model test and numerical modeling method. The results have shown that rising of groundwater table caused buoyant force to the tunnel and the fluctuation of rainwater in the tunnel generated loosening of surrounding ground. It is recommended to evaluate the effect of the long-term water pressure variation in the design of a multi-purpose tunnel.

• Journal of information and communication convergence engineering
• /
• v.14 no.2
• /
• pp.115-121
• /
• 2016

Currently there is a lack of literature on SPICE-level models of double-gate (DG) tunnel field-effect transistors (TFETs). A DG TFET compact model is presented in this work that is used to develop a SPICE model for DG TFETs implemented with Verilog-A language. The compact modeling approach presented in this work integrates several issues in previously published compact models including ambiguity about the use of tunneling parameters A_k and B_k, and the use of a universal equation for calculating the surface potential of DG TFETs in all regimes of operation to deliver a general SPICE modeling procedure for DG TFETs. The SPICE model of DG TFET captures the drain current-gate voltage (I_ds-V_gs) characteristics of DG TFET reasonably well and offers a definite computational advantage over TCAD. The general SPICE modeling procedure presented here could be used to develop SPICE models for any combination of structural parameters of DG TFETs.

• Explosives and Blasting
• /
• v.31 no.1
• /
• pp.76-86
• /
• 2013

In order to control tunnel blast vibration for adjacent facilities using electronic detonator, Understanding about the characteristics of near-field ground vibration is necessary. The purpose of this paper is to analyze effects of Cut-area and Extension-area vibration in relation to decision of tunnel blast vibration. These data were obtained at the top monitoring positions while ${\bigcirc}{\bigcirc}{\bigcirc}$ tunnel site of "Wonju~Gangneung double railroad section ${\bigcirc}{\bigcirc}$ construction" was passing under the existing road. Thus, tunnel blasting was conducted by tunnel electronic blasting system with 0.01% high delay-time accuracy. It can be possible that not only keeping maximum charge per delay-time but also preventing amplification of vibration which is occurred by delay-time scatter using common detonators. Additionally, V-Cut was changed into Burn-Cut. The results was presented that vibration level of extension-holes were higher than Cut-holes. Therefore, near-field ground vibration can be effectively minimized using electronic detonators in the Cut area. And also more effective way to reduce tunnel blast vibration is full-face blast using electronic detonators.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.5
• /
• pp.779-797
• /
• 2017

Recently, underground road construction is attracting attention because the ground transportation facilities in the urban area have reached the saturation level and traffic volume has increased and the air pollution has risen. Construction of underground roads is not only reduce trafficjam in downtown but also design the city eco-friendly, so existing roads as well as new roads go underground. It is essential to construct divergence tunnels that serve as IC (interchage) and JC (Junction) when constructing underpasses. Therefore, the analysis of the effect of the existing tunnel by the divergence tunnel should be considered. In this study, numerical analysis is performed to analyze the effect of existing tunnel on the excavation of the divergence tunnel. The divergence tunnels were set in 5 cases at $45^{\circ}$ intervals in the clockwise direction starting from the lower part of the existing tunnel. In each case, numerical analyses were carried out by using the DCM (Displacement Controlled Model) for applying the volume loss of 0.5%, 1.0% and 1.5%. As a result, when the volume loss increased, the effect on displacement, fracture range, and effect on stability increased as well. In addition, it was confirmed that the divergence tunnel located directly underneath is the weakest for the stability, and the case where the divergence tunnel is located diagonally rather than the vertical and horizontal direction is found to be vulnerable to displacement and lining destruction.