• Journal of Construction Engineering and Project Management
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• 제4권1호
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• pp.29-36
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• 2014

Tunnelling has become a preferred method of construction for road and highway projects in countries with a lot of hilly slope geological conditions such as found in Malaysia. However the construction works of a tunnelling project are usually complicated and costly, which consequently impose great risks to the parties involved. This paper identifies the key significant risks and sub-risks for tunnelling construction projects in Malaysia through a case study. Interview has been used as the solitary means to determine the significant risks from contractor's eleven key project personnel who were directly involved in the tunnelling construction such as consultant, construction manager and tunnel engineers. The importance of the risks identified is then prioritised and ranked via the Analytic Hierarchy Process (AHP)'s pairwise comparison approach to determine their criticality towards a successful delivery of project. As a result, three key risks have been identified as significant for the tunnelling case study project, namely health and safety, cost overrun in construction and time overrun in construction. Two sub-risks each of the latter categories, which are cost underestimation and unforeseen events (cost overrun in construction) as well as plant and machinery failure and delay in material delivery (time overrun in construction), have occupied the top five overall risk ranking.

• Journal of KIBIM
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• 제6권1호
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• pp.25-32
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• 2016

In BIM environments for infrastructures, civil structures such as road, bridge and tunnel etc., created into 3D objects, integrated with their properties, securing BIM design productivity is very critical during 3D modeling. To solve this issue, configuring BIM libraries so that the users can utilize prefabricating in advance 3D objects that have been applying repeatedly during BIM design is essential so much. Current BIM libraries have made focused on Ready-Made for architectural facilities. However, establishing environment for delivering BIM library for civil facilities is very sparse. Accordingly, this study developed a web-based sharing system for delivering BIM library contents based on standardized drawing for civil area. To do this, we have analyzed core features and operation system of BIM library sharing system in domestic and overseas. Besides, functional requirements that are necessary for developing BIM library sharing system was derived, and through operation scenario configuration, the web-based system was developed according to the detailed mechanism. It is expected that this system can enhance BIM design productivity during library based modeling, and can be utilized as construction supporting tools that can help construction managers to make a design change.

• Explosives and Blasting
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• 제31권2호
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• pp.25-31
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• 2013

In this case of "Seongnam~Yeoju double-lanes railroad construction", there were resident houses and gas pipe which were concerned about damages from vibration and noise. Especially, gas pipe which is a diameter of ${\varphi}500mm$ was located under the ground along upside road. The limit of vibration was 1.0cm/sec to protect gas pipe. The electronic blasting systems have been used to control vibration & noise not only gas pipe but also resident houses. The results of tunnelling were successfully conducted with effective vibration control and quick excavation by electronic blasting without any damages to adjacent facilities.

• Wind and Structures
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• 제11권4호
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• pp.257-273
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• 2008

A number of passive aerodynamic drag reduction methods were applied separately and then in different combinations on an intercity bus model, through wind tunnel studies on a 1:20 scale model of a Mercedes Benz Tourismo 15 RHD intercity bus. Computational fluid dynamics (CFD) modelling was also conducted in parallel to assist with flow visualisation. The commercial CFD package $CFX^{TM}$ was used. It has been found that dramatic reductions in coefficient of drag ($C_D$) of up to 70% can be achieved on the model using tapered and rounded top and side leading edges, and a truncated rear boat-tail. The curved front section allows the airflow to adhere to the bus surfaces for the full length of the vehicle, while the boat-tails reduce the size of the low pressure region at the base of the bus and more importantly, additional pressure recovery occurs and the base pressures rise, reducing drag. It is found that the CFD results show remarkable agreement with experimental results, both in the magnitude of the force coefficients as well as in their trends. An analysis shows that such a reduction in aerodynamic drag could lead to a significant 28% reduction in fuel consumption for a typical bus on intercity or interstate operation. This could translate to a massive dollar savings as well as significant emissions reductions across a fleet. On road tests are recommended.

• Tunnel and Underground Space
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• 제14권5호
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• pp.305-317
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• 2004

Due to the steep and narrow characteristic of domestic coal beds, the slant chute caving or sub-level caving method have been mainly adopted in Korea, whereas the long-wall mining has been widely used all around world. However, the slant chute caving or sub-level caving method have disadvantage of not giving much information on the scale and characteristic of abandoned mines. Hence, those information on the abandoned mines in Korea are not easily available. In this study, based on the characteristic investigation of the domestic mining methods, the geological survey and safety analysis were carried out for Donghae highway section 2. Finally, the optimum ground reinforcement methods for that site were selected.

• Journal of Korean Society of Transportation
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• 제23권5호
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• pp.57-64
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• 2005

Recently, several national construction projects such as Chunsung Mt. section of Kyungbu High Speed Rail or Sapae Tunnel of Seoul Outer Ring Road have been delayed or suspended due to the objections of residents or environmental organizations. Considering the development of democracy, increased public participation and interests on environmental issues in Korea, the generation of these social conflicts may be natural phenomenon. However, it is necessary to find measures to effectively implement major construction project and save costs related to social conflicts. In this paper, PI techniques in the United States are investigated and in comparison, the weakness and improvement plans for Korea's current public participation system have been suggested.

• Tunnel and Underground Space
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• 제10권3호
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• pp.475-480
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• 2000

The propagation of blast vibration and the damping characteristics depend on both the mechanical properties of rock mass and weight charge. In this study, the characteristics of propagation and damping were analyzed by FLAC. The construction site was the second Kwang-ju circulating road. Taguchi method which is one of experimental design methods was used for determination of input data and parameter levels. The results showed that rock density was the most dominant of variables being concerned in this study, which affect the propagation of blast vibration.

• International Journal of Highway Engineering
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• 제14권6호
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• pp.1-11
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• 2012

PURPOSES : The purpose of the study was to examine dynamic features of concrete after mixing a little macro fiber with small aspect ratio and long length utilized for bridge, tunnel and shotcrete for tensile performance and crack control in domestic/overseas countries with cement concrete pavement mix. METHODS : Coarse aggregates with small aspect ratio and macro fibers with maximum length of approximately 32 mm are introduced in small quantities in the mix proportions of concrete pavement so as to prevent loss of the workability. Then, this study intends to evaluate the applicability of macro fibers in the mix proportions of concrete pavement by examining the basic construction performance, as well as the change of toughness, the equivalent bending strength and the flexural toughness index caused by compression, bending, tension and the flexural stress-displacement curve. RESULTS : As the results, in each kind of macro fiber, polyvinyl alcohol fiber and steel fiber displayed a good performance. CONCLUSIONS : In 0.2 and 0.3% of fiber contents, it is appeared that polyvinyl alcohol fiber has a large effect on improvement of tensile performance and steel fiber on improvement of deforming performance of bending stress.

• Tunnel and Underground Space
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• 제27권5호
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• pp.295-302
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• 2017

In this study, a new quantitative instrumentation and measurement standards applicable to the field of mining has been proposed to improve the problems of the current measurement practices that apply the measuring standards of the civil engineering field (road, railway, etc.). With the data coordination of the mine reclamation corporation, we collected data on ground subsidence in the abandoned mine area, and studied various techniques for establishing a new management reference value based on the manual measurement data measured in the field. As a result, new instrumentation and measurement standards is set up and proposed by using statistics like the average value, the third quartile, the 95% confidence, and the maximum value.

• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.81-88
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• 2001

Electrical resistivity is one of physical property of the earth and measured by electrical resistivity survey, electrical resistivity logging and laboratory test. Recently, electrical resistivity is widely used in determination of rock quality in road and railway tunnel design. To get more reliable rock quality data from electrical resistivity, it needs a lot of test and study on correlation of resistivity and rock quality. Firstly, we did rock property test in laboratory, such as uniaxial compressive strength(UCS), p wave velocity, Young's modulus and electrical resistivity. We correlate each test results and we found out that electrical resistivity has exponentially related to UCS and P wave velocity and linearly related to Young's modulus. And we accomplished electrical resistivity survey in field site and carried out electrical resistivity logging at in-situ area. Also we peformed rock classification, such as RQD, RMR and Q-system and we correlate electrical resistivity to rock classification results. We found out that electrical resistivity logging data are highly correlate to RQD, Q and RMR. Also we found out that electrical resistivity survey data are lower than electrical resistivity logging data when there are faults or fractures. And it cause electrical resistivity survey data to lowly correlate to RQD, Q and RMR.