Lee S.,Korea Institute of Geoscience and Mineral Resources |
Kim Y.-S.,Yooshin Engineering Corporation |
Oh H.-J.,Korea Institute of Geoscience and Mineral Resources
Journal of Environmental Management | Year: 2012
The aim of this study is to analyze the relationship among groundwater productivity data including specific capacity (SPC) and transmissivity (T) as well as its related hydrogeological factors in a bedrock aquifer, and subsequently, to produce the regional groundwater productivity potential (GPP) map for the area around Pohang City, Korea using a geographic information system (GIS) and a weights-of-evidence (WOE) model. All of the related factors, including topography, lineament, geology, forest, and soil data were collected and input into a spatial database. In addition, SPC and T data were collected from 83 and 81 well locations, respectively. Four dependent variables including SPC values of ≥6.25m 3/d/m (Case 1) and T values of ≥3.79m 2/d (Case 3) corresponding to a yield (Y) of ≥500m 3/d, and SPC values of ≥3.75m 3/d/m (Case 2) and T values of ≥2.61m 2/d (Case 4) corresponding to a Y of ≥300m 3/d were also input into a spatial database. The SPC and T data were randomly selected in an approximately 70:30 ratio to train and validate the WOE model. Tests of conditional independence were performed for the used factors. To assess the regional GPP for each dependent variable, W + and W - of each factor's rating were overlaid spatially. The results of the analysis were validated using area under curve (AUC) analysis with the existing SPC and T data that were not used for the training of the model. The AUC of Cases 1, 2, 3 and 4 showed 0.7120, 0.6893, 0.6920, and 0.7098, respectively. In the case of the dependent variables, Case 1 had an accuracy of 71.20% (AUC: 0.7120), which is the best result produced in this analysis. Such information and the maps generated from it could be used for groundwater management, a practice related to groundwater resource exploration. © 2011 Elsevier Ltd.
Joo K.-S.,Hyundai Engineering |
Suh Y.-H.,Hyundai Engineering |
Park K.-H.,Hyundai Engineering |
Huh D.-H.,Yooshin Engineering Corporation |
And 2 more authors.
Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics | Year: 2012
The subsea tunnel with a length of 6.927 km between Boryung and Taean will be the first mined road tunnel in Korea. This tunnel, two-lane two tubes, has been planned to pass approximately maximum 60m under seabed and 80m under sea level. It is a drained tunnel under control of water ingress by grouting for watertight and is excavated by blasting. Project status is on the end of the detail design stage and construction will be started in the end of 2010. This paper intends to introduce some considerations about the secondary lining design considering the water inflow in the mined subsea tunnel. Firstly it is introduced the design concept of the secondary lining considering the water inflow and the drained material characteristic. And, the combination of the rock loads and residual water pressure is studied and proposed. © 2012 Taylor & Francis Group, London.
Oh H.-J.,Korea Institute of Geoscience and Mineral Resources |
Kim Y.-S.,Kyungpook National University |
Kim Y.-S.,Yooshin Engineering Corporation |
Choi J.-K.,Korea Ocean Research and Development Institute |
And 2 more authors.
Journal of Hydrology | Year: 2011
This study analyzed the relationships between groundwater specific capacity (SPC) and its related hydrological factors to assess the sensitivity of each factor and map the regional groundwater potential for the area of Pohang City, Korea, using a geographic information system (GIS) and a probability model. All related factors including topography, geology, lineament, and soil data were collected and entered into a spatial database. SPC data were collected from well locations, and SPC values of ≥6.25m3/d/m, corresponding to a yield of 500m3/d, were input to a spatial database. SPC data were then randomly selected in a 66/34 ratio to train and validate the model. A frequency-ratio model and sensitivity analysis were used to determine the relationships between SPC and its related factors and the importance of SPC-related factors. Sensitivity analysis allows for comparison of the combined effects of all factors except for one. The validation of the groundwater potential map overlain by all factors showed 77.78% accuracy. In the sensitivity analysis, the best accuracy was obtained by omitting ground elevation data (78.64%), and the worst accuracy resulted when soil texture was not included (76.64%). The results show that soil texture had the greatest effect on the groundwater potential and ground elevation had the least effect. Such information and the maps generated from it can be applied to groundwater management and groundwater resource exploration. © 2010 Elsevier B.V.
Ahn J.-H.,Yonsei University |
Yoon J.-H.,Yonsei University |
Kim J.-H.,Yooshin Engineering Corporation |
Kim S.-H.,Yonsei University
Journal of Constructional Steel Research | Year: 2011
Integral abutment bridges can reduce the amount and cost of construction and maintenance work since they do not have expansion joints and shoes in order to increase stability and durability of the bridges' system. Integral abutment bridges normally have single-row H-pile systems to resist the behaviors under service loading conditions such as thermal loading. In order to transfer member forces between abutments and H-pile, the abutmentpile connection in the integral abutment bridge should have rigid behavior. Therefore, the installation of reinforcing bars and minimum installed length of the piles in the concrete abutment are required to resist bearing force and deformation caused by shear forces and bending moments. This study examines the abutmentpile connections in the integral abutment bridge to improve the shear and bearing resistance of concrete abutment and constructability of abutmentpile connections for the single-row H-pile system with weak axis. Three types of new abutmentpile connections are proposed in this study. They feature transverse reinforcing bars perforated in H-pile, stud connectors, and perfobond rib connectors on the flange of H-pile, respectively. They are intended to increase the stiffness and strength so that they will better resist the bearing force caused by deformations and rotations at abutment H-pile concrete. Loading tests and FE analysis were conducted to evaluate the stiffness and behaviors of proposed connections for half scale abutmentH-pile connection specimens. From the test results, proposed abutmentH-pile connections were evaluated to secure sufficient stiffness, rotational stiffness, and bearing strength. © 2011 Elsevier Ltd. All rights reserved.
Jeon J.-H.,Yooshin Engineering Corporation |
Kho S.-Y.,Seoul National University |
Park J.J.,Transportation Institute |
Kim D.-K.,Seoul National University
KSCE Journal of Civil Engineering | Year: 2012
Land-use inventories and household travel surveys, which are often used to collect socio-economic and traffic data for urban transportation planning models, are costly and time-consuming. The required time and cost can be reduced by using an aggregated Traffic Analysis Zone (TAZ) structure and network model since they are closely related to detail of the TAZ structure and network model. However, it is important to determine the aggregation levels, depending on the purpose and subject of the research, because the use of the aggregated data could lead to aggregation bias. The main of this paper is to analyze the spatial aggregation level effects of TAZ structures and network models on traffic assignment results using an urban transportation planning model based on data from Seoul City. The second objective is to propose two new aggregation levels for the planning assessments of higher-class roads. Several evaluation indices are available for analyzing the aggregation effects of TAZ structures and network models and for investigating the proposed aggregation levels. Results have shown that the proposed TAZ structures and network models can produce traffic assignment results within a reasonable range of error and also reduce the time and cost required for surveys and analyses. The results of this study can provide transportation planners with a quantitative guideline and objective, rational data for use in developing proposals, and preliminary feasibility studies of transportation facilities. © 2012 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg.
Lee M.-J.,Yooshin Engineering Corporation |
Hwang G.,Yooshin Engineering Corporation |
Lim J.,Yooshin Engineering Corporation |
Kwon S.-D.,Chonbuk National University
Long Span Bridges and Roofs - Development, Design and Implementation | Year: 2013
This paper presents the prototype design results of a suspension bridge of which main span reaches up to 2800m. A new design code (draft) developed with supports of the Super Long Span Bridge R&D Center in Korea has been applied to the design. Influences on the design of the main cable, the steel pylon and the orthotropic deck plate are presented. Moreover, the result of optimization on the deck cross-section by wind-tunnel test is summarized. In addition, a preliminary study on a bridge design life has been performed. Important infrastructures such as super long-span bridges may need a longer bridge design life than that of other structure. A bridge with a longer design life essentially requires higher construction cost. A proposal to raise economical efficiency is suggested.
Park S.,Yooshin Engineering Corporation |
Roberts L.A.,South Dakota School of Mines and Technology |
Misra A.,University of Kansas
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012
With the increasing use of augered cast-in-place and drilled displacement piles in new construction, it is important that proper design parameters be incorporated when evaluating pile performance using reliability-based design methods. Although augered piles can be distinguished from bored piles, including drilled shafts, and driven piles by the magnitude of the effective stress changes they produce in the vicinity of the pile during construction, the current design methods for augered piles generally use the same design methods as those used for bored or driven piles. To enhance the efficiency of the augered piles, a unique design method must be developed. This paper focuses on developing a design methodology for axially loaded augered piles installed in predominately sandy soils using the t-z method. To develop the design parameters for augered piles, back-calculation of the t-z parameters was conducted using static loadetest data. The data from 17 static pile load tests conducted on augered piles from construction sites were obtained. Load-settlement and load-transfer curve fittings were performed using the t-z model to back-calculate a set of soil-pile interfacial and tip parameters, along with their variability. Correlations of the back-calculated t-z model parameters with the standard field investigation data were conducted, and the most-promising correlations were incorporated into the t-z modelebased design methodology. Subsequently, the t-z method for augered pile design was evaluated by comparing the predicted and measured load-settlement and load-transfer curves. In addition, the t-z method was used to perform probabilistic load-settlement analyses and obtain resistance factors applicable to the load and resistance factor design approach. © 2012 American Society of Civil Engineers.
Kim S.-H.,Yooshin Engineering Co. |
Kim K.-L.,Yooshin Engineering Co. |
Hong E.-J.,Yooshin Engineering Co. |
Kim C.-D.,Yooshin Engineering Co. |
And 3 more authors.
ITA-AITES World Tunnel Congress 2016, WTC 2016 | Year: 2016
Subsea tunnel needs to be built over 50km long to connect between nations and continents. However there are only 19 tunnels longer than 5km in Korea, and there is no history of constructing and operating a tunnel longer than 50km. As the concept of a subsea tunnel, which withstands high water pressure and has an extremely long length is completely different from that of a land tunnel, all kinds of the latest technologies for tunnel construction are required such as survey and analysis of geology, design and construction under high water pressure, ventilation and prevention of disasters within an ultra long tunnel. Therefore, this paper describes the determination of tunnel cross-section under a high speed railway, structural stability, ventilation and fire safety under construction and operation, etc. through the virtual project for the length of 108km subsea tunnel under high water pressure of maximum 20bars from Honam to Jeju island in Korea.