• Explosives and Blasting
• /
• v.23 no.1
• /
• pp.41-46
• /
• 2005

Overbreak is an inevitable during tunnel excavation. It significantly affects tunnel construction cost and safety The overbreak occurs due to incorrect expectations to the geologic structures, excessive charge or strength of explosives, etc. This paper introduces multi-hole drilling method to minimize the overbreak in tunnel excavation. Although the drilling cost of the method is more expensive than those of the existing other drilling method, it is expected at that cost will be reduced.

• 건설안전세미나
• /
• s.5
• /
• pp.3-95
• /
• 1994

• Journal of the Korea Institute of Building Construction
• /
• v.7 no.3
• /
• pp.131-137
• /
• 2007

To predict deep excavation wall movements is important in the urban areas considering the cost and the safety in construction. Failing to estimate deep excavation wall movements in advance causes too many problems in the projects. The purpose of this study is to propose the forecast model of deep excavation wall movements using artificial neural networks. The data of the Deep Excavation Wall Movements which were done form Long research is used of Artificial neural networks training and apply the real construction work measured data to the Artificial neural networks model. Applying the artificial neural networks to forecast the deep excavation wall movements can significantly contribute to identifying and preventing the accident in the overall construction work.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.4 no.1
• /
• pp.13-25
• /
• 2002

The construction method for Young Dong Tunnel has been chosen following detailed risk assessment. In this paper, the specific risks to the project programme, associated with adopting either mechanical excavation in the form of a shielded TBM, or drill and blast excavation methods, are assessed. From the risk assessment results, and taking other important factors into account, such as project sensitivity and local experience, the recommendation is made that the relatively low risk drill-and-blast method is the most appropriate for construction of Young Dong Tunnel.

• Proceedings of the KSR Conference
• /
• 2002.05a
• /
• pp.200-206
• /
• 2002

The construction method for the Young Dong Tunnel has been chosen following detailed risk assessment. In this paper, the specific risks to the project programme, associated with adopting either mechanical excavation in the form of a shielded TBM, or drill and blast excavation methods, are assessed. From the risk assessment results, and taking other important factors into account, such as project sensitivity and local experience, the recommendation is made that the relatively low risk drill-and-blast method is the most appropriate for construction of the Young Dong tunnel.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.2
• /
• pp.37-43
• /
• 2019

After the new standards for labor hours has been released, various problems come up in construction field, such as income reduction of employees, extension of construction period and increased construction cost. Although it is expected that the impact of the new standard on the construction industry is more worse than other industries form the view of productivity, not much works have been done to identify those impacts. Thus, this research proposes the standard construction processes, excavation cycle, and unit construction period for NATM tunnel project based on 'Construction Standard Production Rates.'The study also investigated the impact of reduced labor hours on the management of work crews, construction periods and costs of tunnel projects. The results showed that under the 52 labor hour standard, the construction periods for the excavation work and whole project was increased by 20% and 8.9%, respectively, but the construction costs for the excavation work and whole project was decreased by 1.4% and 0.6%, respectively.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1998.10a
• /
• pp.233-240
• /
• 1998

• Magazine of the Korea Institute for Structural Maintenance and Inspection
• /
• v.19 no.4
• /
• pp.48-51
• /
• 2015

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.6D
• /
• pp.623-629
• /
• 2010

Recently, the Shield TBM (Tunnel Boring Machine) construction method is used gradually to increase at the Tunnel Constructin site. However the design and application of the Shield TBM were carried out without sufficient investigation of the ground conditions in the construction site. Due to insufficient understanding to the corresponding equipment is frequently occurring unexpected construction cost and extension of a construction period. The most suitable alternative construction method was determined by analyzing tunneling rate, duration, construction cost of shield machine and tunneling data of alternative method. The result of the case study is suggested as follows. First, the accurate soil exploration on the construction site should be preceded to prevent from tunneling stoppage and schedule delay. Second, the most suitable selection of the shield machine to the ground conditions of the construction site should be executed based on the investigation. Third, the best alternative method for boring of hard rock section is 'hard rock blasting after open cut and cover method'.

• Journal of the Korean GEO-environmental Society
• /
• v.12 no.9
• /
• pp.5-11
• /
• 2011

Recently, large and deep excavations are increasing. The damage of adjacent structures due to excavation has steadily increased with increasing construction demand. Especially in urban development and poor conditions, the excavation adjacent to the subway structures has caused a lot of problems. This paper was reviewed that the underground excavation and reinforcement of the status process through a case study on the field. And stability analysis through the case study evaluates applicability for reasonable reinforcement method by numerical analysis. As a result, the strata distribution condition of all 16 sites consisted of landfill from the top and distributed in the order of deposits, weathered soils, weak rock from the bottom. Also, when proceeding the excavation adjacent to structures, the location of site and layer conditions have highly effect on the results of the construction. Therefore, this study was applied reinforcement method to protect damage by excavation. Displacement and settlement were within allowable criterion and hence, stability of structure was analyzed as safe.