• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.700-705
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• 2006

The latest system of GIS has been changing from 2 dimension to 3 dimension. According to the rapid growth of the fields linked to 3D GIS, 3D GIS has variously affected the public field, the national defense field. and the industrial field. This study estimated sight distance safety of curve section considering the environmental impact based on 3D GIS. Sight distance is calculated from the relation between road which keeps the three-dimension character and driver gaze, so it needs to consider both plane and vertical for the accurate measuring. This study made analysis of the sight distance through considering the environmental impact with driving simulation of design speed 80km/h and running speed 60-120km/h.

• Magazine of the Korea Concrete Institute
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• v.7 no.1
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• pp.109-116
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• 1995

In tnis study, the impact factors of a simply supported highway bridge due to a vehicle moving across the span are presented. This variable has received cons~derable attention in recent years, both analytically and experimentally. The KBDC specification equation has a maximum 30 percent value which decreases with span length. The results of field tests showed that the dynamic load effects are mostly lower t.hari present KBDC value and that the impact factor does not vary significantly with spar1 as implied in KHUC. The rnain parameters affecting lmpact are the br dge approach. bumps, and other pavement roughness. In thls study, based on test results, three values of impact factors are provided by correlating the roughness of the surface to the deck condition survey values. The present study proposes reasonable impact factors for the strength evaluation of highway bridges. This study may be extended to the evaluation of existing brdges.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.155-160
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• 2008

The urban areas have various landuses such as residential, commercial, industrial and official purposes that are highly concerned with human activities. The other landuses are relating to vehicle activities, which are roads, parking lots, bridges, parks etc. The mainly using landuses by human activities are possessing three different areas that are buildings, parking lots/roads and landscapes. Of these areas, the buildings and landscapes can be classified as non-pollution areas. However, the parking lots or roads are classifying as the main pollution areas because of vehicle activities. Therefore, the landuses arising the nonpoint pollution during a storm in urban areas are roads and parking lots. The vehicles are emitting lots of nonpoint pollutants such as metals and particulate matters and it is impacting on water qualities and aqua-ecosystems nearby the city areas. Therefore, this research was conducted for characterizing the pollutant types and determining the EMCs (Event Mean Concentrations) and unit pollutant loads during a storm. The monitoring was performed on 9 locations such as highways, service area, tollgates, parking lot and bridges. All of the landuses selected for monitoring are concerned with transportation. The results can be effectively used to predict the pollutant loading before urban planning and to select the BMPs (Best Management Practices) for reducing the pollution.

• Journal of Korean Society of Disaster and Security
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• v.15 no.4
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• pp.11-20
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• 2022

The general non-destructive inspection method for anchor bolts in Korea applies visual inspection and hammering inspection, but it is difficult to check corrosion or fatigue cracks of anchor bolts in the part included in the foundation or in the part where the nut and base plate are installed. In reality, objective investigation is difficult because inspection is affected by the surrounding environment and individual differences, so it is necessary to develop non-destructive inspection technology that can quantitatively estimate these defects. Inspection of the anchor bolts of domestic road facilities is carried out by visual inspection, and since the importance of anchor bolts such as bridge bearings and fall prevention facilities is high, the life span of bridges is extended through preventive maintenance by developing non-destructive testing technology along with existing inspection methods. Through the development of this technology, non-destructive testing of anchor bolts is performed and as a technology capable of preemptive/active maintenance of anchor bolts for road facilities, practical use is urgently needed. In this paper, the possibility of detecting defects in anchor bolts such as corrosion and cracks and reliability were experimentally verified by applying the ultrasonic test among non-destructive inspection techniques. When the technology development is completed, it is expected that it will be possible to realize preemptive/active maintenance of anchor bolts by securing source technology for improving inspection reliability.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.485-498
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• 2014

In this paper, vehicle-bridge interaction analysis under a series of moving vehicles to simulate a lane load was performed to estimate impact factor of the main cable, hanger and girder for the selected suspension bridges with 404m and 1545m main span. Korea Bridge Design Code(Limit State Design) was selected for the live model in which KL-510 truck was modeled 6-d.o.f. vehicle and a lane load was simulated by a series of single-axle vehicles. For the 404m main span bridge, hinge-type and floating-type girders at the tower were considered to examine the impact factor according to the connection and supporting type of the girders. The parameters considered herein are the types of live load-a truck only and a truck plus lane load, eccentricity of moving vehicles, road surface roughness and vehicle speed. The road surface roughness was randomly generated based on ISO 8608 and it was applied to the truck only. The impact factors were also evaluated by using the influence line method that is commonly used in cable-supported bridges and compared with those from vehicle-bridge interaction analysis.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.1-13
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• 2007

As girders and towers in cable-stayed bridges are subject to bending moments as well as axial forces, the conventional load rating equation, which considers only the single force effect, cannot be used to evaluate the rating factors of cable-stayed bridges. The load rating equation for components in cable-stayed bridges is not currently established yet. In this paper, we propose load rating equations for girders and towers in cable-stayed bridges using the interaction equations for beam-column members. Moving load analyses were performed for the cases of a maximum axial compressive force, maximum positive moment and maximum negative moment for each component in cable-stayed bridges and detailed procedures to apply proposed equations were presented. The Dolsan Grand Bridge was used to verify the validity of proposed equations. The conventional load rating equation overestimates rating factors of girders and towers in the Dolsan Grand Bridge, whereas proposed equations properly reflect the axial-flexural interaction behaviour of girders and towers in cable-stayed bridges.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.145-152
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• 2011

Current Bridge Specification for Highway Bridges adopts a simplified method to determine sectional forces of abutment wing by dividing its area into four sections. This simplified method was developed in Japan when numerical analysis was not mature and computer resources were expensive. This simplified method has been with us without modification. This study evaluates the problem of current design practice to improve the design guideline for abutment wing. In this study, a finite element model of abutment wing based on shell elements was developed to obtain accurate sectional force. In addition, foreign design specifications regarding abutment wing were thoroughly examined. It has been observed that sectional forces obtained from the simplified method produce inaccurate results under various geometric shapes. Thus, it is recommended that two dimensional plate analyses should be adopted for future design of abutment wing wall.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.3
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• pp.59-68
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• 2010

Seismic performances of existing structures should be assessed with more accuracy for cost-effective retrofits. Existing bridges are assessed by the current guidelines in which a simple method has been adapted considering the technical level of engineers of the historical time of construction. Recently many probabilistic approaches have been performed to reflect the uncertainties of seismic input motions. Structures are modeled frequently with the neglection of soil foundations or modeled occasionally with elastic soil spring elements to consider the effect of the soil on the structural response. However, soil also shows nonlinearity under seismic events, so this characteristic should be reflected in order to obtain a more accurate assessment. In this study, a 6-span continuous bridge has been analyzed under various seismic events, in which the soil was represented by equivalent linear spring elements having different properties according to the intensities of the input motions experienced. The seismic vulnerabilities with respect to the failure of piers and the dropping of the super-structure were evaluated on the basis of the analysis results.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.182-182
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• 2011

현재 국내에서 PSC 거더의 제작은 주로 포스트텐션방식을 사용하고 있다. 포스트텐션방식은 콘크리트 양생 후 긴장력을 도입하여 제작회전율이 높은 특성을 가지나 쉬스, 그라우팅, 정착장치 등이 요구되어 조립과정이 복잡하고 제작단가가 높다. 교량에 적용되는 PSC 거더를 포스트텐션방식 대신에 프리텐션방식으로 제작한다면 제작단가를 대폭 감소시킬 수 있을 것이나, 교량용 PSC 거더의 길이가 일반적으로 30~50m이므로 공장에서 제작하여 현장으로 운반하는 것은 운반비용의 상승 및 운반 가능한 크기의 제한을 받게 된다. 운반의 문제를 해결하기 위해서는 현장에서 PSC 거더를 제작하여야 하는데 현장에 긴장대를 고정식으로 설치하는 것은 제작단가의 상승으로 이어져 경제성을 잃게 된다. 따라서 현장에서 사용할 수 있도록 이동식 긴장대를 제작한다면 경제성을 갖춘 프리텐션방식의 PSC 거더 생산이 가능할 것이다. 50m급 이동식 긴장대에는 약 10MN에 이르는 매우 큰 긴장력이 가해져 이동식 긴장대가 콘크리트 양생전까지 이 긴장력을 저항하여야 한다. 본 논문에서는 유한요소 해석프로그램인 ABAQUS를 사용하여 50m급 PSC 거더를 생산할 수 있는 이동식 긴장대를 모델링하여 약 10MN에 이르는 긴장력이 가해질 때에 이동식 긴장대의 각 구성요소의 거동특성 및 하중에 대한 안전성 및 좌굴에 대한 안정성 확보 여부를 해석적으로 파악하고자 한다. 이동식 긴장대는 구성요소인 정착블럭(긴장BOX)과 중간연결블럭으로 나누어 모델링하였다. 정착블럭(긴장BOX)은 다수의 강판을 4절점 쉘요소(S4R)를 사용하여 직육면체의 BOX 형상에 내부를 보강한 단면으로 구성하였고, 중간연결블럭은 H형강 2개를 일체화한 긴장대 거더와 콘크리트 바닥판 블록이 볼트로 합성된 구조이며, H형강은 4절점 쉘요소(S4R), 바닥판블럭은 8절점솔리드요소(C3D8R)를 사용하였다. 긴장대거더와 바닥판블럭은 합성거동을 하도록 weld option을 사용하여 부분적으로 결합하였다. 정적해석결과 이동식 긴장대에 발생하는 응력은 도로교 설계기준에 SS400 강재의 허용응력 140MPa 보다 작으며 선형탄성좌굴 해석결과 가력하중의 2.22배 약 21MN의 하중이 가력되어야 전체좌굴이 발생하게 될 것으로 추정된다. 해석결과를 보아 50m급 PSC 거더를 생산할 수 있는 이동식 긴장대는 하중에 대한 안전성 및 좌굴에 대한 안정성을 확보하고 있는 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.235-241
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• 2009

PSC girder bridge is known to be more economical than other types of bridges and has been usually applied to a span range of 25 m to 35 m according to the standard shapes for highway bridges in Korea. The spans of the recently developed new types of PSC girders are also limited to 50 m at most. In this study, therefore, feasibility of the long-span PSC girder that reaches more than 50 m is investigated by applying several strategies from the perspectives of materials, design and construction. A systematic procedure is proposed that can be used to assess the effect of each strategy on the span. The proposed scheme adopts a graphical approach that represents a relationship between the number of prestressing tendons and the span, and is derived on a basis of safety assessment equations of the girder in each stage of fabrication and in service. In the companion paper, the amount of span extension is quantitatively evaluated by applying the proposed scheme into a sample PSC girder bridge.