• Korean Journal of Construction Engineering and Management
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• v.8 no.1 s.35
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• pp.141-149
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• 2007

Simulation has considerable potential as the tool of construction management, but in the case of domestic, it is at an early stage applying simulation to micro-process assesment. For applying simulation to the construction process, much effort is needed to collect input data and to build the model including the characteristics of site. This study introduces the methodology to collect operation data of construction equipment and build the simulation model, then verifies the model with the operation data. In addition, this study identifies main factors to determine the cycle time of the muck hauling system so that it suggests the method of construction process planning through operation and combination of construction equipments.

• Journal of Industrial Technology
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• v.5
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• pp.59-64
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• 1985

The remarkable economic growth achived during 1960-1980 in Korea inevitablely demanded the expansion and maintenance of the harbors and their auxiliary seashore facilities. One of the most important elements in the basic besign for the expasion of a harbor and its auxiliary facilities is, of course, the proper determination of the design wave which reflects the major characteristics of the seashore under consideration. In this study, the parameters of significant waves for the industrial harbors on East Coast, Muck-Ho and Po-Hang, are first computed by means of computer programming using S.M.B and P.N.J methods, respectively. Then the design waves with the return periods of 5-200 years were estimated by frequency analysis of the significant waves. A comparison of the design waves with the observed wave data during the past 10 years made it possible to determine the optimum value of design wave at the two harbors. The important results of this study can be summarized as follows; 1) It seems appropriate to take the design wave hieghts with the return period of 50 years at Muck-Ho and Po-Hang as 6.9 and 5.8 meters respectively. 2) It was found that for the determination of design waves on East Coast of Korean Peninsula P.N.J method works better than S.M.B method in predicting the significant wave, and the Log-Normal distribution fits best to the wave data which were put to frequency analysis.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.827-831
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• 2007

For applying simulation to the construction process, much effort is needed to collect input data and to build the model including the characteristics of site. This study introduces the methodology to collect operation data of construction equipment and build the simulation model, then verifies the model with the operation data. In addition, this study identifies main factors to determine the cycle time of the muck hauling system and offers reasonable decision making data using the simulation based planning of construction equipment operation.

• Geomechanics and Engineering
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• v.35 no.6
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• pp.571-580
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• 2023

During EPB shield tunnelling, construction speed and safety are severely affected by spewing. In this study, a theoretical seepage model is established to capture of the effects of screw conveyor geometry and turbulent flow on spewing. Experimental test results are used to verify the proposed theoretical seepage model. It is found that the seepage is greatly affected by the length of screw conveyor and soil permeability. The proposed model can increase the screw conveyor length and reduce soil discharge sections simultaneously, the permeability of treated muck thus decreases by one order of magnitude. By using the proposed theoretical seepage model, the criterion of critical soil permeability used to identify spewing is proposed. When the water head applied at tunnel face reaches 40 m and 50 m, the critical permeability coefficients of treated muck should be less than 10^-5 m/s and 10^-6 m/s to avoid spewing. For a given permeability coefficient of soil, the water flow rate is overestimated if structural characteristics of screw conveyor is not considered. Consequently, the occurrence of spewing is greatly overestimated, which increases construction cost substantially.

• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.277-284
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• 2002

In recent years, data broadcasting kas been drawing muck attention with glowing importance. In this paper, we implement a DASE middleware which is crucial for the data-ready DTV settop box. The software has been ported to a prototype system and tested with real time broadcasting streams.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.463-473
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• 2017

Bentonite swells when it comes into contact with water and makes it a viscous fluid. Thus it is widely used in civil engineering works for waterproofing. Utilizing the properties of bentonite, the slurry shield TBM supports excavated face with pressurized slurry as well as transporting excavated muck. When bentonite is in contact with seawater, due to the change of double layer thickness, its expandability and viscosity are lowered. This may cause problems for excavation stability and muck discharge due to the increase of sea water inflow when Slurry TBM is used under sea water conditions. In this study, the change of slurry condition caused by the inflow of sea water during tunnel excavation with Slurry TBM was investigated and a slurry management guideline was proposed. For this purpose, a laboratory test was carried out based on the slurry management criterions applied in the field, and a method applicable to the field where sea water is affected has been proposed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.203-211
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• 2014

This paper presents the screw conveyor operation efficiency of shield TBM in soft ground. In order to study the screw conveyor operation efficiency, the experimental and theoretical studies were carried out. In experimental study, the operating amounts of muck were examined and compared due to the screw conveyor operating parameters including types (Shaft and Ribbon screw), angles of screw and conveyor. The results obtained from the laboratory model tests were analysed and evaluated to suggest the most suitable muck operating parameters during the shield TBM tunnelling in soft ground. In conclusion, it is found the operation parameters to increase the screw conveyor efficiency. In addition, the information presented in this paper may be useful for developing the design technology of shield TBM in the future.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.163-176
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• 2017

The Discrete Element Method (DEM) has been widely used in civil engineering as well as various industrial fields to simulate granular materials. In this study, DEM was adopted to predict the performance of the face plate-type earth pressure balance (EPB) shield TBM (Tunnel Boring Machine). An analysis of the TBM excavation performance was conducted according to two pre-defined excavation conditions with the different rotation speeds per minute (RPM) of the cutterhead. The TBM model which was used in this study has a 6.64 m of diameter and six spokes. Also, 37 precutters and 98 scrapers at an each spoke were modeled with a real-scale specification. From the analysis, compressive forces at the cutterhead face, shield and cutting tools, resistant torques at the cutterhead face, muck discharge rate and accumulated muck discharge by the screw auger were measured and compared.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.129-139
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• 2018

The Discrete Element Method (DEM) has been widely used in granular material researches. Especially, if material has a large deformation, such as ground, it can be a useful method to analyze. In this study, to simulate ground formations, DEM was used. The main purpose of DEM analysis was to investigate the numerical model which can predict the TBM performance by simulating excavating procedure. The selected EPB TBM has a 7.73 m of diameter and six spokes. And two pre-defined excavation conditions with the different rotation speeds per minute (RPM) of the cutterhead was applied. In the modeled cutterhead, the open ratio of cutterhead was 21.31% and number of cutters (including disc cutter and cutter bit) was 219. From the results, reaction forces and resistant torques at the cutterhead face and cutting tools, were measured and compared. Additionally the muck discharge rate and accumulated muck discharge by the screw auger were evaluated.

• Tunnel and Underground Space
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• v.32 no.4
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• pp.272-284
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• 2022

This study conducted tunnel blasting to evaluate the blasting effect of a shear thickening fluid-based blasting stemming material and a sealed plug device under development. STF single stemming and STF stemming materials were combined with plugs to a tunnel blasting to which the SAV-Cut method was applied, and the advanced rate and fragmentation of tunnel blasting muck pile were compared when sand stemming was used. Tunnel advanced rate was evaluated using a 3D laser scanner. When the STF stemming material and STF stemming material with the plug were compared to the sand stemming material, it increased by 5.7 and 5.36%, respectively. As a result of evaluation of the fragmentation of tunnel blasting muck pile, it was the best when the STF stemming material was applied, and it decreased by about 61% compared to the case of sand stemming blasting. However, no significant improvement in blasting effect was observed with the application of plug devices.