Code-compliant seismic design should be essentially applied to realize the so-called emulative performance of precast concrete (PC) lateral force-resisting systems, and this study developed simple procedures to design precast industrial buildings with intermediate precast bearing wall systems considering both the effect of seismic and blast loads. Seismic design provisions specified in ACI 318 and ASCE 7 can be directly adopted, for which the so-called 1.5S y condition is addressed in PC wall-to-wall and wall-to-base connections. Various coupling options were considered and addressed in the seismic design of wall-to-wall connections for the longitudinal and transverse design directions to secure optimized performance and better economic feasibility. On the other hand, two possible methods were adopted in blast analysis: 1) Equivalent static analysis (ESA) based on the simplified graphic method and 2) Incremental dynamic time-history analysis (IDTHA). The ESA is physically austere to use in practice for a typical industrial PC-bearing wall system. Still, it showed an overestimating trend in terms of the lateral deformation. The coupling action between precast wall segments appears to be inevitably required due to substantially large blast loads compared to seismic loads with increasing blast risk levels. Even with the coupled-precast shear walls, the design outcome obtained from the ESA method might not be entirely satisfactory to the drift criteria presented by the ASCE Blast Design Manual. This drawback can be overcome by addressing the IDTHA method, where all the design criteria were fully satisfied with precast shear walls’ non-coupling and group-coupling strength, where each individual or grouped shear fence was designed to possess 1.5S y for the seismic design.

PURPOSES : Safety Evaluation of Wind Loads of Renewable Energy and Photovoltaic Power Structures. METHODS : Structural safety evaluation was conducted on the wind load of 3kW Photovoltaic Power Structures using ABAQUS. Wind speed was reviewed for 36m/s and 60m/s. Effective Mass and Mass Contribution of Photovoltaic Power Structures was utilized up to 90%. 7 steps were set and applied to structural analysis. RESULTS : As a result of the structural analysis, it was confirmed that the long-term blowing load was affected rather than the size of the wind load. Weak areas were identified at the point of the horizontal beam rather than the modules of the Photovoltaic Power Structures. In particular, it was confirmed that stress exceeding the allowable stress was generated at the junction. In order to secure the safety of Photovoltaic Power Structures, it is judged that reinforcement of the branch is necessary. CONCLUSIONS : The safety of Photovoltaic Power Structures structures for wind load is influenced by persistence rather than the size of the wind load. Therefore, in order to prevent this, it is judged that reinforcement of the branch is necessary.

As various accidents have occurred in underground spaces, we aim to improve the quality validation standards and methods as specified in the Regulations on Producing Integrated Map of Underground Spaces devised by the Ministry of Land, Infrastructure and Transport of the Republic of Korea for a high-quality integrated map of underground spaces. Specifically, we propose measures to improve the quality assurance of pipeline-type underground facilities, the so-called life lines given their importance for citizens’ daily activities and their highest risk of accident among the 16 types of underground facilities. After implementing quality validation software based on the developed quality validation standards, the adequacy of the validation standards was demonstrated by testing using data from two-dimensional water supply facilities in some areas of Busan, Korea. This paper has great significance in that it has laid the foundation for reducing the time and manpower required for data quality inspection and improving data quality reliability by improving current quality validation standards and developing technologies that can automatically extract errors through software.

주소 관련 미래 산업의 확장으로 새로운 주소체계에 대한 수요가 증가하였으며, 특정 사물에 주소를 부여하는 체계인 사물주소의 중요성이 강조되고 있다. 현행 사물주소는 행정안전부가 제작 및 배포하고 있으며 데이터베이스 제작 등 사물주소의 활성화를 위한 노력이 지속되고 있다. 하지만 현행 사물주소는 하향식 방법으로 부여되고 있기 때문에 수요자 응답형 정보제공 대응에 미흡한 현실이다. 이에 본 연구에서는 상향식 방법으로 운영 중인 포켓몬 고 DB와 사물주소 DB의 공간적 분포를 탐색함으로 써 사용자 참여형 주소정보 생성 및 적용 가능성을 제시하였다. 각 DB의 지점별 티센 폴리곤을 생성한 뒤 ANOVA 분석을 수행한 결과 두 DB간의 면적 차이가 있음을 확인하였다. 또한 지니 계수를 산출하여 분포 불평등성을 확인하여 DB를 통합하여 활용하는 방법을 제시하였다. 본 연구는 사물주소의 확산과 알기 쉬운 대국민 주소정보체계 확립에 정책적인 활용이 가능할 것이다.

PURPOSES : The purpose of this study was to quantitatively evaluate the variability of LiDAR performance indicators, such as intensity and Number of Point Cloud(NPC), according to various environmental factors and material characteristics. METHODS : To consider the material characteristics of road safety facilities, various materials (Reference Material(RM), reflective sheet, matte sheet, granite, plastic, and rubber) were used in a darkroom, and the performance indicators of LiDAR were repeatedly measured in terms of changes in the measurement distance, rainfall, and angle of observation. RESULTS : In the case of standard reflective materials, the intensity measurement value decreased as the measurement distance and rainfall increased. The NPC showed a tendency to decrease as the measurement distance increased, regardless of rainfall intensity. For materials with high-intensity values, it was found that rainfall intensity and color had negligible effect on the change in intensity compared with the measurement distance. However, for materials with low-intensity values, it was found that the measurement distance, rainfall intensity, and color all had a significant effect on the change in intensity. CONCLUSIONS : For materials with high-intensity values, it was found that rainfall and color had negligible effect on change in intensity compared with the measurement distance. However, for materials with low-intensity values, the measurement distance, rainfall, and color all had a significant effect on the change in intensity value.

PURPOSES : Experimental findings pertaining to the mechanical properties of calcium aluminate cement (CAC)-based repair mortars incorporated with anhydrite gypsum (AG) are described herein. METHODS : To prepare the mortars, three different levels of AG were adopted and the ratio of water–cementitious materials was fixed at 0.50. For comparison, mortar composed of ordinary Portland cement was prepared. The fluidity, setting time, compressive and bond strengths, absorption and surface electric resistivity of the mortars were measured at predetermined periods. RESULTS : The incorporation of AG increases the fluidity but decreases the setting time of the CAC-based repair material system. However, the AG in the CAC mixes does not effectively enhance the compressive strength of the mortars owing to the decreased formation of CA hydrates, such as CAH10 and C2AH8. Meanwhile, the mortar with 10% AG shows excellence absorption. CONCLUSIONS : The mechanical properties of CAC based-mortars rely significantly on the amount of AG incorporated. However, further studies regarding the microstructure and durability of CAC-AG repair mortars must be conducted to obtain the optimal mixture.

Based on the random-vibration-theory methodology, dynamic responses of nuclear facilities subjected to obliquely incidental and incoherent earthquake ground motions are calculated. The spectral power density functions of the 6-degree-of-freedom motions of a rigid foundation due to the incoherent ground motions are obtained with the local wave scattering and wave passage effects taken into consideration. The spectral power density function for the pseudo-acceleration of equipment installed on a structural floor is derived. The spectral acceleration of the equipment or the in-structure response spectrum is then estimated using the peak factors of random vibration. The approach is applied to nuclear power plant structures installed on half-spaces, and the reduction of high-frequency earthquake responses due to obliquely incident incoherent earthquake ground motions is examined. The influences of local wave scattering and wave passage effects are investigated for three half-spaces with different shear-wave velocities. When the shear-wave velocity is sufficiently large like hard rock, the local wave scattering significantly affects the reduction of the earthquake responses. In the cases of rock or soft rock, the earthquake responses of structures are further affected by the incident angles of seismic waves or the wave passage effects.

본 논문은 대형 시설물의 점검 및 진단을 위한 외관조사시 영상기반 스캐닝 시스템의 성능 및 정확도를 정량적으로 평가하기 위한 것으로, 도로터널, 철도터널, 지하철과 같은 대형 터널 시설물의 복공 라이닝을 대상으로 영상기반 스캐닝 분석 결과, 균열, 박리, 박락, 철근노출 등 각종 손상의 검출 성능과 정확도를 육안조사, 터널 스캐닝 분석 후 확인조사 데이터를 이용하여 비교 분석하였다. 제안된 터널 스캐닝 시스템의 균열손상 검출성능은 육안조사 분석결과 대비 개소 수 및 면적물량에 있어 월등히 우수함을 확인하였으며, 균열손상 증감을 고려한 균열손상은 현장 확인조사 결과 95%이상의 검출 정확도를 확보하고 있는 것으로 평가되었다.

PURPOSES : This study is performed first to define the aging of road facilities and to analyze the effects of environmental factors on the deterioration of median barriers. METHODS : The aging of road facilities is defined using an analytical hierarchy process (AHP). The first stage is associated with the period, facilities, and maintenance, whereas the second stage is associated with the details. The effects of environmental factors on the deterioration are analyzed by measuring the carbonation depth and compression strength. Two regions, i.e., Gangwon and Busan, are compared separately. Top, middle, and bottom samples are analyzed for both regions. RESULTS : Based on the result of the AHP analysis, weights for period (0.220), function (0.410), and maintenance (0.370) are derived. The average carbonation depths are 11.12 and 9.78 mm for Kangwon and Busan, respectively. The estimated values of compressive strength at Gangwon are 19.7 MPa (Wonju), 24.7 MPa (Samcheok A), and 25.9 MPa (Samcheok B), 20.2 MPa (Haeundae), 23.8 MPa (Yeongdo), and 29.5 MPa (Nam). CONCLUSIONS : The aging of road facilities is associated with subpar functionality and durability. Furthermore, the median barriers constructed in the Gangwon region deteriorated more significantly than those in the Busan region owing to environmental factors. In addition, the bottom samples are more affected by aging than the top samples.

The purpose of this paper is to understand the key factors for efficient maintenance of rapidly aging facilities. Therefore, the safety inspection/diagnosis reports accumulated in the unstructured data were collected and preprocessed. Then, the analysis was performed using a text mining analysis method. The derived vulnerabilities of tunnel facilities can be used as elements of inspections that take into account the characteristics of individual facilities during regular inspections and daily inspections in the short term. In addition, if detailed specification information and other inspection results(safety, durability, and ease of use) are used for analysis, it provides a stepping stone for supporting preemptive maintenance decision-making in the long term.

PURPOSES : This study attempts to reveal the limitations of the current asset valuation methods for road infrastructure, based on national accounting standards. We proposed novel asset valuation methods, namely; the nearly land price and ratio-based method(NLP&R), and the consumption-based depreciation method(CBD). In addition, we verified the possibility of application through the research on the road network of Daejeon Metropolitan City. METHODS : This study proposes a novel re-evaluation method for road facilities. Regarding land, the authors proposed calculating the asset value, using the arithmetic average of the publicly announced land price of nearby land, located on both sides of the road section. For structures, a consumption-based depreciation(CBD) method that reflects the current condition level of structures was proposed. RESULTS : Owing to the application of the evaluation method for the current guidelines, land value was evaluated at 0.84-8.12 trillion won, pavement value at 8.75 trillion won, tunnel value at 0.26 trillion won, and bridge value at 2.09 trillion won. Owing to the application of the novel evaluation method proposed in this study on road facilities of Daejeon City, land value was estimated at 6.96 trillion won, tunnel value at 0.28 trillion won, and bridge value at 2.40 trillion won. CONCLUSIONS : We discovered that four current evaluation methods for land prices have some limitations that were over-or underestimated. However, in the case of the novel evaluation method proposed in this study, the value of land assets was estimated at 6.96 trillion won, by applying the nearly land price and ratio-based method. The road pavement was evaluated at approximately 8.75 trillion won, by applying the newly calculated re-procurement cost per unit in 2019. Bridges and tunnels using the new evaluation method were evaluated to be higher than the existing evaluation methods, because the current damaged condition of the facilities was reflected in the valuation. It was concluded that the proposed method is more objective and reliable than the current evaluation methods.

PURPOSES : The purpose of this study was to analyze the effect of reducing nitrogen oxide concentration in a photocatalyst (titanium dioxide) using statistical methods such as the Anderson-Darling test. METHODS : To compare and analyze the effect of reducing the nitrogen oxide concentrations in titanium dioxide, titanium dioxide was applied to the public road, and data acquisition in terms of nitrogen oxide concentration was conducted from roads with/without applying titanium dioxide (test section and reference section, respectively). Then, the probabilities of occurrence of nitrogen oxide concentrations in the test and reference sections were estimated and compared using the Anderson-Darling test. RESULTS : According to the comparison and analysis of probabilities in the nitrogen oxide concentration of the test and reference sections, the probabilities of nitrogen oxide concentration on December 4th were estimated as ‘High’ (17.5%, 37.9%), ‘Moderate’ (30.5%, 40.8%), and ‘Low’ (52.0%, 21.3%), respectively, and on December 5th, as ‘High’ (20.6%, 39.1%), ‘Moderate’ (26.2%, 33.0%), and ‘Low’ (53.2%, 27.9%), respectively. In addition, the probabilities of nitrogen oxide concentration in the test and reference sections were analyzed on December 6th as ‘High’ (16.5%, 36.8%), ‘Moderate’ (27.9%, 38.5%), and ‘Low’ (55.6%, 24.8%), respectively. CONCLUSIONS : Based on the results of this study, in the test section with application of titanium dioxide, the nitrogen oxide concentration was found to have a low probability, and in the reference section, the nitrogen oxide concentration was found to be higher than that in the test section. Therefore, it can be concluded that titanium dioxide applied to road facilities has a nitrogen oxide reduction effect.