https://doi.org/10.12652/Ksce.2025.45.1.0001

허광희(Heo, Gwang Hee );이재훈(Lee, Jae Hoon);방건혁(Bang, Geon Hyeok);전승곤(Jeon, Seung Gon);이유재(Lee, Yu Jae)

This study focused on developing a MANTiS wireless measurement system for performance-based monitoring of structures, utilizing ESP32 and MPU-6050 motion sensors. An experiment was conducted to verify the performance of the acceleration and frequency response of the MANTiS, determining its suitability for bridge monitoring. The experiment revealed errors of 0.90 % in the dynamic range and 0.40 % in the frequency range, indicating that the system is reasonably applicable for structural measurements. Furthermore, measurements of the data acquisition rate about communication distance and sampling rate confirmed that stable data acquisition is achievable without data loss, even at a sampling rate of 200 Hz over distances of up to 80 m. Finally, to evaluate the multi-module measurement capabilities of the developed MANTiS, vibration data were collected from six points to analyze its dynamic characteristics. The analysis compared the performance of the MANTiS with that of a commercial wired measurement system. The results indicated that the developed MANTiS wireless measurement system exhibited a difference of 0.79 % in the primary mode and 0.09 % in the secondary mode when compared to the commercial wired system. Therefore, it is concluded that the MANTiS can be effectively utilized for measuring construction structures, such as bridges.

https://doi.org/10.12652/Ksce.2025.45.1.0007

최범균(Choi, Beom Gyun );박종건(Park, Jong Gun);서동주(Seo, Dong Ju);전형민(Jun, Hyung Min);윤창호(Yun, Chang-Ho);허광희(Heo, Gwang Hee)

For snow removal/deicing on the pavements in winter, when a voltage is applied to the mortar through the embedded electrodes, heat is generated due to the resistance caused by the current flow. The generated heat can be effectively used to melt snow/ice accumulated on the pavements. This paper investigated the properties of conductive mortar containing multi-walled carbon nanotubes (MWCNT) and micro steel fibers (MSF). The synergistic effects of MWCNT and MSF on the microstructure, heating performance, electrical and flexural strength properties of conductive mortar were examined. The results demonstrated a clear synergistic effect between MWCNT and MSF. As the mixing concentration of MWCNT and the applied voltage were increased, the heating performance improved significantly, and the electrical resistance decreased substantially. Scanning electron microscope (SEM) images confirmed that MWCNT were evenly dispersed within the cement matrix together with MSF, forming conductive paths and acting as bridges. However, the aggregation of some MWCNT was found to diminish both heating performance and flexural strength in the conductive mortar.

https://doi.org/10.12652/Ksce.2025.45.1.0013

(Mukharromah, Nur Indah);(Lim, Taejeong);(Park, Hyun Woo)

The elastic guided wave technique is a well-known non-destructive testing method for detecting cracks, where wave scattering coefficients play a crucial role in analyzing the transmission and reflection caused by a crack. Previous studies predicting wave scattering coefficients have been widely conducted using the finite element method. However, the finite element method requires a huge computation time, particularly in the high-frequency range. Therefore, closed-form solutions for the wave scattering coefficients are needed for rapid crack assessment through inverse analysis. This study aims to derive closed-form solutions for the wave scattering coefficients associated with transmission and reflection at the crack in the elastic waveguide considering axial-bending coupling. The axial-bending coupling on the dynamic behavior of the waveguide at the crack is modeled through elementary rod and Timoshenko beam theories. Analytical solutions are derived separately for propagating bending and axial incident waves. The proposed solutions are validated through the comparison with the numerical results from the finite element method reported in previous literature.

https://doi.org/10.12652/Ksce.2025.45.1.0023

전승곤(Jeon, Seung Gon );이재훈(Lee, Jae Hoon);허광희(Heo, Gwang Hee);이유재(Lee, Yu Jae)

To control the oscillations that threaten the safety of bridges, we have developed a Friction Tuned Mass Damper (FTMD) that can control the off-tuning phenomenon, a disadvantage of TMD, while maintaining the form of a Tuned Mass Damper (TMD) with proven control performance. The FTMD utilizes an electromagnet as the mass and is designed and manufactured to supply voltage to the friction plate attached to the FTMD to enable variable control depending on the supply time. The control performance of the developed FTMD was compared with the control performance of a TMD that removed the friction plate from the FTMD. In the bending behavior control experiment, an inertial type bending machine was attached to a model cable-stayed bridge and forced bending was performed at 0.03 Hz intervals from 3.50 Hz to 3.71 Hz, and FTMD, TMD, and LVDT were attached to the center span where the maximum displacement occurs. As a result of the experiment, the FTMD showed excellent control performance with a displacement damping ratio of 43.11 % at 3.50 Hz, where the maximum vertical displacement occurs in the center, and the displacement damping ratio of 26.84 % at 3.65 Hz, where the largest out-of-synchronization phenomenon occurs when the TMD is installed.

https://doi.org/10.12652/Ksce.2025.45.1.0029

노명현(Noh, Myung Hyun );이상열(Lee, Sang Youl)

High corrosion resistance hot-dip alloy plated steel sheets are new materials with excellent corrosion resistance and have 5 to 10 times more corrosion resistance than conventional hot-dip galvanized steel sheets. In developed countries, the demand for high corrosion resistance hot-dip alloy plated steel sheets has recently increased significantly, but in Korea, there are relatively few cases of applying such high corrosion resistance steel sheets to road safety facilities. In this study, the optimal specifications of the high-speed B-grade guardrail applied with a highly corrosion-resistant hot-dip zinc aluminum magnesium alloy-plated steel sheet were derived, and the crash and structural performance were investigated by performing a real-vehicle crash test and numerical analysis. The existing SB2/SB4 grade adopted open-type guardrails that are commercially available without change to the SB3-B/SB5-B grade, and the optimization process was performed through crash analysis using LS-DYNA. As a result of the rail arrangement design, visibility was secured by arranging the upper, middle, and lower rail heights at equal intervals, and the shock-absorbing blockout was designed integrally to secure both passenger protection performance and strength performance. As a result of the actual vehicle collision test, both small and large vehicles passed the high-speed section B-grade performance evaluation criteria, and both numerical analysis and crash test results met the allowable values. Therefore, it was analyzed that the B-grade guardrail with the highly corrosion-resistant plated steel sheet proposed in this study secured corrosion resistance and sufficient collision performance for the high-speed section. In addition, the results derived from this study show that if the optimal specification is derived through variable analysis based on crash analysis, the risk of failure of the collision test can be reduced and development costs can be reduced.

https://doi.org/10.12652/Ksce.2025.45.1.0043

방건혁(Bang, GeonHyeok );이재훈(Lee, JaeHoon);이유재(Lee, YuJae);서상구(Seo, SangGu);허광희(Heo, GwangHee)

This study aims to analyze the load measurement accuracy of the EnBWIM(Energy Based Bridge Weigh In Motion) system based on the operational characteristics of vehicles. The operational characteristics of vehicles include load, speed, number of axles, and wheel material, but this study is limited to only vehicle load, speed and wheel material. For the analysis of the load measurement accuracy of the EnBWIM system, indoor experiments were conducted using a model bridge and model vehicles with loads of 2 kgf, 5 kgf, and 9 kgf. The results of the indoor experiments conducted under various vehicle operating conditions showed that the maximum error rate in load measurement by the EnBWIM system was 0.7 %, indicating high accuracy. The indoor experiments for speed variations increased the speed of the model vehicles from 0.2 m/s to 0.7 m/s in increments of 0.1 m/s, and the error in load measurement by the EnBWIM system decreased to as low as 0.03 % with increasing speed. Furthermore, the performance verification experiments of the EnBWIM system according to wheel material showed that the system had higher accuracy in measuring heavier vehicles as the wheel material was harder. Through the experiments verifying the load measurement performance of the EnBWIM system according to vehicle operating characteristics, it is determined that the EnBWIM system can accurately measure the load of moving vehicles with an error rate of less than 1 %.

https://doi.org/10.12652/Ksce.2025.45.1.0051

박연준(Park, Yeon Jun );박성현(Park, Seong Hyeon);윤현웅(Yoon, Hyeon woong);장낙섭(Jang, Nag Seop);오홍섭(Oh, Hong Seob)

Corrosion of rebar can reduce the safety and durability of structures, and various studies on FRP(Fiber Reinforced Polymer) Rebar reinforced concrete are being conducted to use it as a substitute for rebar. In this study, the Harmony Search algorithm was used for the optimal design of the CFRP Rebar reinforced concrete section, and the optimal section satisfying the minimum cost and deflection conditions was derived through the ACI 440.1R-15 example model. For comparison purposes, both single-objective and multi-objective optimization were performed, and the results from each optimization showed differences. The single-objective optimization resulted in extreme cross-sectional designs that prioritized either cost or deflection. To mitigate this issue and account for structural uncertainties, a multi-objective optimization was performed, considering both cost and deflection as objectives. The single-objective Harmony Search algorithm showed a trade-off between cost and deflection. However, the multi-objective Harmony Search algorithm showed that the Pareto front was uniformly distributed. A section that balances the minimum cost and minimum deflection was derived, and both the cost and deflection were low when the parameters HMCR=0.7 and PAR=0.3 were set.

https://doi.org/10.12652/Ksce.2025.45.1.0059

김태형(Kim, Tae Hyoung );서동주(Seo, Dong Ju);윤창호(Yun, Chang Ho);박종건(Park, Jong Gun);송기창(Song, Ki Chang);허광희(Heo, Gwang Hee)

Multi-walled carbon nanotubes (MWCNT) have high electrical and thermal conductivity and are attracting attention as a heating material. These properties can efficiently convert electrical energy into heat and can be utilized in various fields such as heating devices, medical heating devices, smart fibers, and cement composites. In this study, MWCNT were mixed with polyurethane dispersion (PUD) to prepare coating solutions, which were then coated on the surface of polyethylene terephthalate (PET) film to prepare MWCNT conductive coating films. At this time, the transmittance, surface morphology, self-heating, and electrical properties of the MWCNT conductive coating film as a function of the different mixing ratios of MWCNT were analyzed. The results showed that as the amount of MWCNT added increased, the electrical resistance of the MWCNT conductive coating film rapidly decreased, while the self-heating effect tended to increase. It was confirmed through field emission scanning microscope (FE-SEM) that MWCNT were evenly dispersed on the surface of the PET film. From the results of this study, it is expected that the MWCNT conductive coating film will be suitable for applications in construction material fields such as entrances and exits of tunnels, snow and ice removal on pavements and bridges, as well as floor heating in buildings.

https://doi.org/10.12652/Ksce.2025.45.1.0065

강인규(Kang, InKyu );김상덕(Kim, SangDuk);김성일(Kim, SungIl)

This study emphasizes the need for a Consequence Management (CM) system for the protection facilities of Korean military ports. Currently, in South Korea, CM is primarily focused on the military sector, with limited application in civilian and governmental areas. In contrast, advanced countries use CM as part of comprehensive security and disaster management frameworks, highlighting the need for a similar approach in South Korea. Especially, due to unavoidable natural phenomena such as typhoons, floods, heavy rains, storms, tsunamis, heavy snowfalls, droughts, and earthquakes, complex damages are occurring. Our country, surrounded by the sea on three sides, is no exception, and protective measures for various coastal defense facilities must be established. The study suggests developing a CM system based on disaster risk analysis in key military port regions and proposes technical and financial strategies for constructing and operating protection facilities. Key recommendations include introducing an Earned Value Management (EVM) system, conducting risk analysis, and adjusting personnel and organizational structures. Additionally, the application of a comprehensive CM framework is proposed to enhance disaster response capabilities and strengthen overall preparedness against potential threats. These measures are expected to contribute to the development of a more robust military CM system in South Korea.

https://doi.org/10.12652/Ksce.2025.45.1.0073

정나영(Jung, Na Young );안제영(An, Je Young);이원효(Lee, Won Hyo);김대환(Kim, Dae Hwan);김태형(Kim, Tae Hyung)

Recent increases in energy consumption and the growing demand for carbon reduction in our country have led to heightened interest in floating offshore wind power. This study investigates the effect of trench formation around suction anchors on the pullout capacity of floating offshore wind turbine suction anchors by performing soil pressure calculations and numerical analyses. The trench near a suction anchor installed in sandy soil is modeled as a V-shape, and a numerical analysis is conducted to calculate the pullout capacity of the suction anchor, considering factors such as trench depth and whether there is soil erosion around the trench. The maximum depth of the trench occurs up to the pad-eye level, with most of the trench formation occurring up to half of the pad-eye depth. The numerical analysis using Midas GTS NX finite element analysis was performed to calculate the changes in pullout capacity with varying trench depths and local or overall soil loss. The results show that the formation of the trench reduces the pullout capacity of the suction anchor in sandy soil. As the trench depth increases, the pullout capacity of the suction anchor decreases, and when the trench is formed overall (rather than locally), the reduction in pullout capacity becomes more significant. Through this study, it was recognized that trench formation around suction anchors of floating offshore wind turbine foundations can affect the pullout capacity of the anchor. It is expected that by developing appropriate solutions, this research will contribute to the advancement of environmentally friendly renewable energy generation using floating offshore wind power.

https://doi.org/10.12652/Ksce.2025.45.1.0081

장성민(Jang, Seong Min );박진성(Park, Jin Seong);유용선(Ryu, Yong Sun);최병훈(Choi, Byoung hoon);정혁상(Jung, Hyuk Sang)

The study analyzes the performance of ITB (Inorganic Thixotropic Backfill) grout, which exhibits properties of reducing leaching and plasticity, through experimental research. It also compares this with the existing TBM backfill method, LW method. The results of unconfined compressive strength tests showed that the ITB grout, when dry curing, exhibited approximately 12 times higher strength than the LW method at the initial curing age (1 hour), and about 7 times higher strength when cured underwater. At the long-term curing age (1 year), it maintained a strength of over 3 MPa regardless of the curing method. Additionally, XRD tests indicated that Ettringite, which affects strength stability at long-term curing, was detected at about 8 % at the initial curing age but increased to over 40 % at the long-term curing age, indicating that ITB grout has excellent long-term durability. SEM-EDX tests revealed the growth of C-S-H gel and a significant amount of Ettringite compared to the LW method, confirming the favorable initial gelling action of ITB grout. The leaching tests showed no detection of harmful substances such as lead, cadmium, and hexavalent chromium, and the ecotoxicity tests indicated no mortality in test fish, with a pH of approximately 8.5. Based on these results, it is concluded that ITB grout is a method advantageous in terms of long-term durability and environmental performance compared to the LW method, making it suitable for use as a backfill material in shield TBM applications.

https://doi.org/10.12652/Ksce.2025.45.1.0093

이강혁(Lee, Kanghyeok );김경석(Kim, Kyung Suk);최정진(Choi, Jeongjin);김용주(Kim, Yongju)

In design phase of a highway construction project, information management problems often arise due to the excessive amount of information generated and changes in workers. A digital collaborative system based on a common data environment (CDE) can be utilized as a way to solve these problems. In this study, two surveys for usability evaluation of a CDE were conducted to demonstrate the CDE developed through previous research to the actual site and analyze its effectiveness in terms of data management. Two sites in design phase of highway were designated as the target of the demonstration, and the scope of the demonstration includes the information sharing, review, and approval process from the creation of the BIM execution plan to the development of the integrated BIM model. 21 engineers who work at the two design phase sites of highway participated in the demonstration, and two surveys were conducted before and after the demonstration. The pre-demonstration survey was conducted to confirm the awareness and need for digital collaboration, and the post-demonstration survey was conducted to confirm the effectiveness of the developed the common data environment software. The results of the two surveys confirmed that digital collaboration based on a CDE can be utilized as a solution to the problem of information management in the design phase. However, additional challenges were also identified, such as the need to improve the CDE software, establish a policy related to CDE, and provide education for designers, so it is expected that the challenges presented should be resolved through further research. The results of this study will serve as basic research for the revitalization of the common information environment and help to increase the efficiency of the construction industry and improve the industry as a whole.

https://doi.org/10.12652/Ksce.2025.45.1.0103

강고운(Kang, Goune );윤원건(Yun, Won Gun);진경호(Chin, Kyung-ho)

The domestic construction industry currently faces challenges such as labor shortages, productivity decline, and an increase in safety accidents. Although smart construction technology research and policy development have been continuously pursued since 2017 to address these issues, the tangible effects experienced on-site remain minimal. To effectively resolve these challenges, it is essential to establish a digital transformation strategy that advances data utilization across all construction processes. This study identifies detailed directions to ensure the practical applicability of future digital transformation technologies in solving industrial problems and facilitating their dissemination within the industry. Through an analysis of domestic and international trends, insights into digital transformation policies and technologies were derived, and a framework consisting of four categories?Digitalization, Intellectualization, Automation, and Manufacturing construction?was established to address nine core technological needs. Additionally, an analysis of 131 technological demands required by the industry was conducted, proposing technological issues, future directions, and expected effects. The findings of this study are anticipated to serve as foundational data for companies in establishing digital transformation technology research and development strategies and determining the direction of future markets.

https://doi.org/10.12652/Ksce.2025.45.1.0113

고재명(Ko, Jae Myung );김시곤(Kim, Si Gon)

Recently, due to the frequent occurrence of fatal or serious accidents at industrial sites, the government has demanded strict management of safety from companies and implemented the Serious Disaster Punishment Act as of January 27, 2022. Nevertheless, railway accidents still occur, and in addition to the major accidents reported in the news, accidents caused by construction work adjacent to railway lines have occurred one after another. The problem is that construction work adjacent to railway lines is gradually increasing due to railway improvement work due to the aging of railway facilities and weakening of the ground, and effective improvement measures are urgently needed. In order to protect the safety of railway operation and prevent risks to railway facilities, the scope of the “Railroad Protection Zone” has been regulated and a “Railroad Operation Safety Manager” has been legally assigned when working within the railway protection zone, but structural problems in utilization and operation continue to occur. In this paper, we study solutions to realistic operational issues (human resource supply issues, management subject issues, laws and systems issues, welfare issues) of “railway operation safety managers” who are essential safety managers for reducing accidents in construction adjacent to railway lines through AHP analysis techniques, and describe efficient improvement measures that can lead to safer on-site management of railway adjacent line construction.

https://doi.org/10.12652/Ksce.2025.45.1.0121

김현우(Kim, Hyunwoo );김경호(Kim, Kyungho);김명수(Kim, Myeongsu);홍석찬(Hong, Sukchan)

In modern times, advancements in spatial information data models have led to the development of diverse forms of spatial information with high LOD(Levels of Detail). Meanwhile, vast amounts of non-spatial information are widely distributed both online and offline, which could significantly enhance the utility of spatial information as an information infrastructure when connected using geocoding technologies. However, traditional geocoding techniques are limited to estimating parcel and building locations, making it impossible to identify detailed locations for non-spatial information. There is a growing need for Semantic Geocoding technologies that utilize high-LOD, object-based data such as CityGML(City Geography Markup Language) to semantically classify and interpret information. Furthermore, the sheer diversity in the formats of non-spatial information poses a limitation on structuring such data and connecting it to spatial information. This necessitates research that interprets the semantics of unstructured, non-spatial information and automatically links it to spatial information without prior structuring. To define the scope of such efforts, this study proposes and defines the concept of Semantic Geocoding LOD. The proposed concept provides criteria for machines to distinguish and interpret location estimation factors within text, serving as a standard for utilizing detailed indoor and outdoor object locations. As a result, this approach enables machines to interpret text and estimate locations more precisely than existing methods, thereby allowing the connection of a greater volume of non-spatial information and enhancing the utility of spatial information.