• Journal of KSNVE
• /
• v.7 no.2
• /
• pp.189-198
• /
• 1997

현재 행해지고 있는 환경 기술자에 의한 공해성 환경영향평가와 택지조성사업, 터널공사, 각종 도로공사, 건물 해체 작업시 이루어지는 발파 기술자에 의한 발파 영향평가 및 토목. 건축 기술자들에 의해 시공현장에서 주로 행해지는 기타 건설 소음. 진동 영향평가는 진단 개념에서 볼 때, 측정목적과 측정대상에 따른 각종 기준적용과 측정방법 및 분석절차 상에서 몇가지 문제점을 안고 있으며 실제 현장 계측시에도 측정위치 선정, 센서부착 방법, 측정 횟수 및 측정 모드 선정 등에서 상당한 오류를 범하는 것을 종종 볼 수 있다. 따라서 본 연구에서는 각종 소음. 진동 영향평가의 현실태 및 피해 대상물에 대한 진단시 우려되는 기준 적용, 측정 및 분석상의 문제점들을 조사하고 개선방안을 살펴봄으로써 소음. 진동 피해진단 기술을 정립하고 향후과제에 대해 논의하고자 한다.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.6
• /
• pp.899-915
• /
• 2018

In this study, in order to construct an eco-friendly advanced road transportation network, the multi-layer tunnel, which is a small-sized car road, is designed to have a height of less than 60 cm. However, the shape of the tunnel is low and the height of the traffic sign is small. In order to solve these problems, traffic sign characters were designed in three dimensions, and the possibility of applying the design of the three - dimensional sign that can obtain greater visibility than the existing signs at the same distance and the possibility verification through virtual simulation were performed. The three-dimensional sign is horizontally installed on the ceiling of the multi-layer tunnel. To be seen vertically, it is enlarged by a certain ratio by the perspective, and the width and height are enlarged. Respectively. In addition, 3D simulation was performed to verify the visibility of the stereoscopic signs when the driver ran through the stereoscopic sign design specifications. As a result of the design and experimental study, it was confirmed that the stereoscopic sign could be designed through the theoretical formula and that it could provide the driver with a larger traffic sign character because there is no limitation of the facility limit compared to the existing vertical traffic sign. Also, we confirmed that it can be implemented in the side wall by using the stereoscopic sign design principle installed on the ceiling part. It was confirmed that the design of the stereoscopic sign can be designed to be smaller as the distance that the driver visually recognizes the sperm is shorter, the height of the protrusion vertically at the lower part of the stereoscopic sign becomes higher. As a result of 3D simulation running experiment based on the design information of the stereoscopic sign, it was confirmed that the stereoscopic sign is visually the same as the vertical sign at the planned distance. Although the detailed research and institutional improvement of stereoscopic signs have not been made in Korea and abroad, it is evolved into a core technology of new road traffic facilities through various studies through the possibility of designing and applying stereoscopic signs developed through this study Expect.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.16 no.3
• /
• pp.299-310
• /
• 2014

Nationally, tunnel and underground constructions are necessary for the environmental sustainability and the efficient use of land space. For the importance of eco-friendly circumstances, 2-arch or large road tunnel has been designed so far. However, such a 2-arch or large tunnel has problems in terms of cost, constructability, construction period, and maintenance. Therefore, in this study, tunnel behavior and stability of rock pillar according to the pillar width and cover depth for parallel tunnels are investigated by performing FE analysis and using empirical formula. According to the results, Rock pillar is reinforced for distributed vertical load by Tie-Bolt due to unpredicted ground deformation, and the reinforced rock pillar's behaviour from the FE analysis shows a quite good agreement with field measurement. According to ground conditions, if the pillar width of the parallel tunnels is reduced, it can be more efficient in use of the tunnel space compared to previous tunnels.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.4 no.2
• /
• pp.123-133
• /
• 2002

In the construction of the road tunnel in mine area, old mine gangways can cause the instability of the tunnel. In this case study, the field investigation is carried out to figure out the location of old gangways adjacent to the tunnel, and their influence on the tunnel stability is estimated according to the location pattern and rock condition by FLAC analysis. The grouting reinforcement of tunnel crown region and old gangway is suggested and its role on assurance of the tunnel stability is also verified. It can be said from this study that the effect of the old gangway on the stability of tunnel varies with the dimension of gangway, distance from the tunnel, rock condition and groundwater, and therefore these paramerter should be compositively considered in the assessment of the tunnel stability.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.11 no.1
• /
• pp.97-105
• /
• 2009

This paper studied the cause of the deterioration of the four 3-Arch tunnels built in mid-1990. The common deteriorations of the four 3-Arch tunnels were longitudinal cracks, leakage and efflorescence at the same parts of lining concrete. Three fourths of 3-Arch tunnels, there was high percentage longitudinal cracks and a quarter was low frequency about longitudinal cracks. So the material reviewed to find out the differences between two groups in construction process and analysis was conducted such as non-destructive testing, precise visual survey and safety evaluation of one tunnel which had bad ground condition As the result, the tunnels were safety condition and the primary deterioration occurred during the construction process, namely, problems arrangement of rebar and the effects of the blast at middle tunnel.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.1
• /
• pp.145-160
• /
• 2018

Long subsea tunnel is subject to many restrictions in terms of spatial limitation when vertical or inclined shafts are built for tunnel ventilation. So, the construction of some artificial island is required to provide ventilation. But, because of construction difficulty and cost increase, it is necessary to minimize the artificial island construction. As a result, ventilation distance become longer and supply airflow becomes excessive due to air leakage, So, duct mounting for temporary ventilation is impossible or fan pressure and power increase exponentially. Therefore, in order to build a long subsea tunnel, it is necessary to overcome these practical problems and to develop technical solution that can keep the comfortable condition of tunnel environment during construction. In previous study, we have found that air leakage is the key factor in solving these problems and experimental results show that the new connection method has a leakage rate of about $1.46mm^2/m^2$ (Jo et al., 2017). In this study, we present the experimental results of the measurement of the leakage rate of the prototype with the new connection method, and analyze experimentally the improvement of the leakage rate when applying the flexible cover inside the duct to improve the leakage performance of the existing connection method.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.4
• /
• pp.94-103
• /
• 2023

Built in urban ares tunnels is necessary to accurately grasp not only the above-ground environment of the tunnel but also the below-ground environment of the tunnel for design and construct. However, fully coupled analysis of stress and flow is very difficult due to the limited function of the tunnel numerical analysis program and difficulty in using program. This can lead to excessive design that increases the construction cost or occur problems that can lead to accidents during construction. In particular, in the case of an urban tunnel has a low layer soil section above the tunnel and the groundwater level exists in the upper layer of the tunnel. Therefore, a reduction in the groundwater level during underground construction may increase the effective stress of the upper layer and cause the ground to subsidence. So It is necessary to design after accurately evaluating the change in the groundwater level. In this study, the tunnel's behavioral characteristics were analyzed through fully coupled analysis of stress and flow according to the drainage type for an urban underground tunnel.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.26 no.1
• /
• pp.19-37
• /
• 2024

Rockbolts are the primary-supports in NATM tunnels and are widely used at tunnel construction sites. Among the rockbolts methods applied in domestic tunnel design, fully grouted rockbolts are the most representative and frequently used. Fully grouted rockbolts exhibit relative behavior between the bolt and the ground due to the grout material. However, during numerical analysis for tunnel design, fully grouted rockbolts are often modeled in a way that does not reflect their behavior characteristics. This may result in underestimating or overestimating the force of the supports. Based on a literature review, it was analyzed that fully grouted rockbolts are modeled using truss element or cable element. To analyze the effect of grout properties of cable elements on rockbolts behavior, this paper compared the behavior of rockbolts in two models: one estimating grout properties based on rockbolt pull-out test data, and another assuming complete adhesion between the rockbolts and the ground by applying large grout properties. Under identical tunnel conditions, the numerical analysis was conducted by modeling the fully grouted rockbolts differently using truss and cable elements, and the tunnel behavior was analyzed. The research results suggest that modeling fully grouted rockbolts as a function of the interface effect between the bolts and the ground, specifically considering grout, is desirable. The use of pull-out test data to simulate the behavior of actual fully grouted rockbolts was considered as a valid approach.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.8 no.3
• /
• pp.219-225
• /
• 2006

Although the round length for tunnel excavation has a major technical and economical impact in conventional tunnelling, there is no coherent procedure available for its determination. In this study, the influence of round length on the behaviour modes of weak rock tunnel was investigated by numerical analyses. Quantitative estimation of the behaviour modes of the face and the unsupported span was established by use of the safety factor for the face stability and the conditional chart. In addition, the optimum round length in the tunnel design stage was investigated based on the detail construction information such as cycle time and material costs. Although this proposed method has some restrictions, it is expected to provide useful information for the optimization of the tunnel excavation, especially in design stage.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.687-687
• /
• 2004

예술의 전당 하부를 통과하는 우면산터널은 예술의 전당 자료관, 오페라하우스, 음악당, 서예관, 미술관 등의 건물과 인접하여 설계되었다. 이들 건물은 진동의 전달경로에 따라 구조-구조의 전달경로인 자료관과 구조-지반-구조의 전달경로인 오페라하우스, 음악당, 서예관으로 분류할 수 있다. 자료관은 하부의 기조 중 일부가 우면산 터널의 통과를 위해 설치한 박스(box) 터널 상부와 구조계를 형성하고 있고, 오페라하우스와 음악당 및 서예관 주변으로는 우면산 터널의 상행선과 하행선이 각각 인접하여 통과하는 구조계를 형성하고 있다. 본 연구는 서울시 서초구 서초동～우면동에 이르는 우면산 터널에 실험 차량이 통과할 때 차량 통행으로 인해 발생하는 진동이 예술의전당 자료관, 오페라하우스, 음악당, 서예관 등의 건축구조물에 전달되는 고체전파음의 발생특성 파악하고, 예술의전당 통과구간에 방진패드에 의한 도로포장 공사 후 그에 대한 효과를 비교하였다. 또한, 우면산 터널 예술의 전당 통과구간에 대하여 다공성 아스팔트로 도로포장한 후 그에 대한 효과도 파악하였다.