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KSCE JOURNAL OF CIVIL AND
ENVIRONMENTAL ENGINEERING RESEARCH

The Journal of the Korean Society of Civil Engineers (KSCE) is a bimonthly journal, founded in December 1981, for the publication of peer-reviewed papers devoted to research and development for a wide range of civil engineering fields.

• Editors-in-Chief: Cheol Woo Park

중공 유리 마이크로스피어를 활용한 경량 소재 개발 Development of a Lightweight Construction Material Using Hollow Glass Microspheres

https://doi.org/10.12652/Ksce.2022.42.4.0449

이난경(Lee, Nankyoung) ; 문주혁(Moon, Juhyuk)

Concrete is the most widely used construction material. The heavy self-weight of concrete may offer an advantage when developing high compressive strength and good dimensional stability. However, it is limited in the construction of super-long bridges or very high skyscrapers owing to the substantially increased self-weight of the structure. For developing lightweight concrete, various lightweight aggregates have typically been utilized. However, due to the porous characteristics of lightweight aggregates, the strength at the composite level is generally decreased. To overcome this intrinsic limitation, this study aims to develop a construction material that satisfies both lightweight and high strength requirements. The developed cementitious composite was manufactured based on a high volume usage of hollow glass microspheres in a matrix with a low water-to-cement ratio. Regardless of the tested hollow glass microspheres from among four different types, compressive strength outcomes of more than 60 MPa and 80 MPa with a density of 1.7 g/cm3 were experimentally confirmed under ambient and high-temperature curing, respectively.

SPI와 DRI를 활용한 의령군 지역의 가뭄 평가 Drought Assessment with SPI and DRI in Uiryeong-Gun

https://doi.org/10.12652/Ksce.2022.42.4.0457

곽제상(Kwak, Jesang) ; 김광섭(Kim, Gwangseob) ; 정영훈(Jung, Younghun) ; 엄명진(Um, Myoung-Jin)

Drought has strong local characteristics, an objective definition or standard that can define the progress or severity of drought is needed and to date, many drought-related studies are being conducted around the world. In this study, Standardized Precipitation Index (SPI), which is a representative meteorological drought index, was calculated, and the drought risk index (DRI) that can consider actual drought was applied to the target area, Uiryeong-gun, by applying the drought vulnerability index (DVI) and the drought hazard index (DHI). A method for practical drought evaluation that can establish a water supply system is presented in this study

비쇄파조건에서 경사식방파제의 상치콘크리트에 작용하는 수평파압: 피복재 어깨폭 영향 Horizontal Wave Pressures on the Crown Wall of Rubble Mound Breakwater Under a Non-Breaking Condition: Effect of the Armour Crest Width

https://doi.org/10.12652/Ksce.2022.42.4.0469

이종인(Lee, Jong-In) ; 임호석(Lim, Ho Seok) ; 조지훈(Cho, Ji Hoon)

To design the crown wall of rubble-mound breakwaters, the horizontal wave load should be available, but determining this load remains difficult. Lee et al. proposed modification factors for Goda’s formula for the horizontal wave pressures on acrown wall. Theempirical formula by Lee et al. was based on a two-dimensional model test with a relatively narrow armour crest width in front of the crown wall. In this study, a series of experiments at the same facility were conducted on the horizontal wave pressures on the crown wall of a rubble-mound breakwater with a wide armour crest width. As a result, the pressures of the unprotected part of the crown wallwere nearly identical to the narrow crest width. However, the pressures of the protected part tended to decrease with a change in the armour crest width. From the experimental results, the horizontal pressure modification factors of Goda’s formula including the armour crest width effect are suggested here and are likely applicable to practical designs of the crown walls of rubble-mound breakwaters covered with tetrapods.

전기화학적 방법을 이용한 Spent Granular Activated Carbon (GAC)의 재생 연구 A Study of the Regeneration of Spent GAC using an Electrochemical Method

https://doi.org/10.12652/Ksce.2022.42.4.0481

이상민(Lee, Sangmin) ; 주수빈(Joo, Soobin) ; 조영수(Jo, Youngsoo) ; 오예지(Oh, Yeji) ; 김형준(Kim, Hyungjun) ; 심인태(Shim, Intae)

This study investigates the characteristics of the GAC adsorption behavior during the operation of a multi-stage cross-flow filtration and GACadsorption process for the purpose of devising an advanced treatment of combined sewer overflows (CSOs) and evaluates the regeneration efficiency of spent GAC that has reached the design breakpoint. During the filtration process, suspended substances are easily removed, but dissolved organic substances are not removed, necessitating a process capable of removing dissolved organic substances for the advanced treatment of CSOs. In general, GAC adsorption has been applied under low-concentration organic conditions, such as for water purification and tertiary treatmentsof sewage, and has rarely been applied under conditions with high organic concentrations, such as with sewage or CSOs. Accordingly, this study will provide a new and interesting experience. Also in this study, the continuous operation and breakthroughcharacteristicsof GAC according to the strength of the inflow organic matter were investigated, electrochemical regeneration was applied to the used GAC, and the regeneration efficiency was evaluated through desorption and re-adsorption tests. The results showed that the breakthrough period was 21 days under high concentration conditions, 28 days at medium concentrations, and 32 days under low concentration conditions. The desorption of adsorbed organic matter through electrolysis occurred in the range of 188 to 609 mgCOD/L depending on the electrolysis conditions, and the effect of the electrolyte type led to the finding that NaOH was slightly higher than H2O2.

하수처리장의 효율적인 Blower Control Logic 개발을 위한 유입수질 기반 공기공급량 적용 연구 Application of the Proper Air Supply Amount Based on the Influent Water Quality for the Development of Efficient Blower Control Logic in Sewage Treatment Plants

https://doi.org/10.12652/Ksce.2022.42.4.0493

여우석(Yeo, Wooseok) ; 김종규(Kim, Jong Kyu)

The standards pertaining to the quality of discharged water in sewage treatment plants are strengthening, and accordingly, facilities in sewage treatment plants are being upgraded. In addition, the discharge water quality of sewage treatment plants must be maintained at a high level, and efficient sewage treatment plant operations have thus emerged as a very important issue. For the efficient operation of sewagetreatment plants, this study applied a basic blowing amount calculation method based on sewage facilities to evaluate the required oxygen amount and blowing amount according to inflow water quality by logicizing various influencing factors. As a result of calculating the amount of air blown by applying actual April water quality data from sewage treatment plant A to the blower demand calculation developedthrough this study, it was found that the average amount of air blown was reduced by about 12%. When the blower demand calculation developed here is applied to an actual sewage treatment plant, the amount of air blown can be controlled based on the inflow water quality. This can facilitate the realization of an autonomous control of sewage treatment plants, in contrast to the existing sewage treatment operation method that relies on operational experience of operator. In addition, it is expected that efficient sewage treatment plants can be operated by reducing blowing amounts and power costs, which will contribute to both energy and carbon savings.

지하수 함양시 최대 주입압력 결정을 위한 연구 Study on the Determination of the Maximum Injection Pressure for Groundwater Rechargement

https://doi.org/10.12652/Ksce.2022.42.4.0501

최진오(Choi, Jin O) ; 정현철(Jeong, Hyeon Cheol) ; 정충기(Chung, Choong Ki) ; 김창용(Kim, Chang Yong)

Required essential technique is to determine the maximum recharge pressure in the well with condition of non-ground failure for therecovery of the groundwater. Based on the classical soil mechanics, the maximum recharge pressure was estimated with the numericalanlaysis and laboratory triaxial test. In the numerical analysis, the maximum recharge pressure is defined as the ground failure stress. The ground failure of the sand was defined as the piping and the one of the caly was to the undrained failure by the confined pressure increment. In the triaxial test, the recharge pressure in the ground was modified by the back pressure in the specimen. In case of sand, the volume strain was dramatically increased at the 93 % of the maximum back pressure, same meaning of the 0 effective stress state. In case of clay, the only radial volume strain was to reached 1.5 % without failure. Therefore, The maximum recharge pressure could be determined with the numerical analysis and triaxial test.

신설 터널굴착이 지중 군말뚝 및 인접 터널의 거동에 미치는 영향 연구 Effect of New Tunnelling on the Behaviour of Grouped Pile and Adjacent Tunnel

https://doi.org/10.12652/Ksce.2022.42.4.0509

김수빈(Kim, Su Bin) ; 오동욱(Oh, Dong-Wook) ; 조현준(Cho, Hyeon Jun) ; 이용주(Lee, Yong-Joo)

The demand for underground infrastructures such as tunnels is expanding due to rapid urbanization. Tunnels in urban areas are usuallyconstructed adjacent to structures supported by piles. Therefore, a proper understanding of pile-tunnel interaction due to tunnel excavation activities is vital. Thus, in this study, a numerical analysis is conducted to analyze pile settlements, ground surface settlements and shear deformations above an existing tunnel subject to the presence of an adjacent tunnelling, with vertical offsets, the number of piles and the pile spacing considered as variables in the analysis. The results show that the vertical offsets between the tunnel crown and the pile tip generatelarger settlement than the pile spacing. In addition, the vertical offset shows an inversely proportional relationship to the shear deformation due to new tunnelling.

동적지도정보 기반 자율주행 정보의 시공간적 활성화 구간 산정 프레임워크 A Framework for Calculating the Spatiotemporal Activation Section of LDM-Based Autonomous Driving Information

https://doi.org/10.12652/Ksce.2022.42.4.0519

강찬모(Kang, Chanmo) ; 정연식(Chung, Younshik) ; 박재형(Park, Jaehyung)

Basically, autonomous vehicles drive using road and traffic information collected by various sensors. However, it is known that there is a limitation to realizing fully autonomous driving with only such technologies and information. In recent, various efforts are being made to overcome the limitations of sensor-based autonomous driving, and efforts are also underway to utilize more specific and accurate road and traffic information, called local dynamic map (LDM). However, LDM-related data standards and specifications have not yet been sufficiently verified, and research on the spatiotemporal scope of LDM during autonomous driving is extremely limited. Based on this background, the purpose of this study is to identify these limitations through an analysis of previous LDM-related studies and to present a framework for calculating the spatiotemporal activation section of LDM-based road and trafficinformation.

KTX 물금역 정차 확정이 양산시 철도 이용자에게 미치는 영향에 관한 연구 A Study of the Effect of the KTX Mulgeum Station Stop on Railroad Users in Yangsan City

https://doi.org/10.12652/Ksce.2022.42.4.0527

최양원(Choi, Yang-Won) ; 장재석(Jang, Jae-Suck) ; 서정렬(Suh, Jeong-Yeal)

The purpose of this study is to predict changing traffic environments and related economic effects by reflecting the changed KTDB and socio-economic indicators pertaining to Mulgeum station, a general railway stop, when it is confirmed as a KTX stop. To analyzethe data of this study, socioeconomic indicators and the general status of transportation facility operations were investigated with reference to related statistical data, centered on the country overall and on Yangsan city in particular. In addition, we investigated and referenced the railroad facility construction plan and train operation plan, which are national high-level plans related to land development and transportation network construction. Currently, there are only ITX trains (4 times/day) and Mugunghwa trains (29times/day) that stop at Mulgeum station in Yangsan, meaning that passengers cannot use KTX trains in the Yangsan area. In particular, the need for a KTX stop at Mulgeum station has been continuously raised because train users in the Yangsan area have inconvenient transportation in that they must travel 40 minutes to Ulsan station or 30 minutes to Gupo station to use the KTX. As a result of analyzing railroad transportation demand that will change in the future as the KTX stop at Mulgeum station is confirmed, the number of passengers boarding and arriving at Mulgeum station is predicted to be 1,674 passengers/day by 2025. In addition, the numbers of train passengers that are converted from Ulsan and Gupo stations due to the stop at Mulgeum station are predicted to be 594 passengers/day boarding and 562 passengers/day arriving by 2025. In the future, if Yangsan citizens use the KTX Mulgeum station, the access time to Mulgeum station can be shortened to 22 minutes from 65 minutes, and it is predicted that the inconvenience of transferring between railroads will be resolved, with the waiting time for transfers reduced by up to a maximum of 40 minutes. Therefore, the economic effect of creating a KTX stop at Mulgeum station was analyzed to be B/C=1.823 when general railroad operating costs are not taken into account and B/C=2.127 when general railroad operating costs are considered. In conclusion, when using KTX trains to visit the Seoul Metropolitan Area, it takes 2 hours and 43 minutes to use Mulgeum station without using Ulsanstation or Gupo station, which is considered to be very effective for reducing travel times and improving the economic feasibility of this development; it is also expected that Yangsan city will be able to improve accessibility and mobility to the Seoul Metropolitan Area by breaking free from the disgrace of being a remote location given its link to KTX in the future.

롤러전압콘크리트 기층의 누적피로손상을 고려한 중하중 도로의 복합포장 두께 설계 Thickness Design of Composite Pavement for Heavy-Duty Roads Considering Cumulative Fatigue Damage in Roller-Compacted Concrete Base

https://doi.org/10.12652/Ksce.2022.42.4.0537

김경수(Kim, Kyoung Su) ; 김영규(Kim, Young Kyu) ; 차이 리후워(Chhay Lyhour) ; 이승우(Lee, Seung Woo)

It is important to design the pavement thickness considering heavy-duty traffic loads, which can cause excessive stress and strain in the pavement. Port-rear roads and industrial roads have many problems due to early stress in pavement because these have a higher ratio of heavy loads than general roads such as national roads and expressways. Internationally, composite pavement has been widely applied in pavement designs in heavy-duty areas. Composite pavement is established as an economic pavement type that can increase the design life by nearly double compared to that of existing pavement while also decreasing maintenance and user costs. This study suggests a thickness design method for composite pavement using roller-compacted concrete as a base material to ensure long-term serviceability in heavy-duty areas such as port-rear roads and industrial roads. A three-dimensional finite element analysis was conducted to investigate the mechanical behavior and the long-term pavement performance ultimately to suggest a thickness design method that considers changes in the material properties of the roller-compacted concrete (RCC) base layer. In addition, this study presents a user-friendly catalog design method for RCC-base composite pavement considering the concept of linear damage accumulation for each container trailer depending on the season.

토목현장에서의 무인비행장치 기반 현장정보 취득 및 분석 시스템 개발 UAV-based Construction Site Monitoring and Analysis System Development for Civil Engineering Management

https://doi.org/10.12652/Ksce.2022.42.4.0549

김창윤(Kim, Changyoon) ; 윤준희(Youn, Junhee)

Due to harsh conditions of construction site, understanding of current feature of terrain and other infrastructures is critical issue for site managers. However, because of difficulties in acquiring the geographical information of the construction sites such as large sites and limited capability of construction workers, comprehensive site investigation of current feature of construction site is not an easy taskfor construction managers. To address these circumstances of construction sites, this study deduce difficulties and applicabilities of unmanned aerial vehicle in the area of construction site management. To confirm applicability of UAV in civil construction project,case study have been conducted on the road construction project. The result of case study proved that the developed system is one of promising technologies that has been studied in construction site management. To improve applicability of UAV for construction and process management information, law and technical issues will be an important area of future study.

클라우드 기반의 인프라 엔지니어링 설계 플랫폼 프로토타입 개발 Development of a Cloud-Based Infrastructure Engineering Design Platform Prototype

https://doi.org/10.12652/Ksce.2022.42.4.0559

조명환(Cho, Myung-Hwan) ; 표길섭(Pyo, Kil Seop) ; 윤승욱(Youn, Seung Wook) ; 정남정(Jung, Nahm-Chung)

Infrastructure engineering is a field that supports construction (assembly) as a representative industry that creates high added value and jobs by combining science and technology with knowledge, though its importance is underestimated. According to a report from the Ministry of Land, Infrastructure and Transport (Korea), the value-added rate (65.3%) of the engineering industry and the employment inducement coefficient (14 employees per billion won) are three times higher than in manufacturing. In particular,the forward value chain (such as project management and basic design) accounts for less than 10~15% of the total project cost but determines the overall price and quality of the infrastructure facilities. In this study, a work break-down system, design support module and databasedevelopment method for road design projects for design platform development is presented. Based on the presented development method, a cloud-based infrastructure design platform's prototype isdeveloped. The developed infrastructure engineering platform is expected to provide a web-based design work environment without time/space restrictions and greatly contribute to winning overseasbusiness orders and securing competitiveness.

관광호텔의 호텔특성 및 입지특성에 따른 에너지사용량 분석 Analysis of the Energy Consumption of Tourism Hotels in Relation to Individual and Locational Characteristics

https://doi.org/10.12652/Ksce.2022.42.4.0571

박혜란(Park, Hyeran) ; 김현수(Kim, Hyunsoo) ; 최열(Choi, Yeol)

This research empirically analyzed the factors associated with the energy consumption of tourism hotels in Busan, Ulsan, and the Kyoungnam region of Korea based on their individual and locational characteristics. The study adopted a comprehensive modelingapproach involving multi-level regression analyses that allowed for improved accuracy by considering the hierarchical structures of thehotels and their locational characteristics. The results indicated that the majority of energy consumption can be explained by the hotels’individual characteristics, including the size of building structure and the services, while their effects vary by region with statistical significance. Furthermore, the proximity to central commercial districts and hotel clusters had a significant influence on thevariability in their energy consumption, indicating that locational factors are also important determinants. The findings here suggest the need for regional energy policies and solutions at various urban scales along with conventional energy policies at the building level and highlight regional responsibilities when attempting to create sustainable tourism industries.

도심 보행을 위한 GIS 거시 평가체계 개발 - 부산을 중심으로 - GIS Macro Evaluation System for Urban Walk - Focusing on Busan -

https://doi.org/10.12652/Ksce.2022.42.4.0581

유연서(Yu, Yeon seo) ; 김종구(Kim, Jong gu)

It is important to create a decent pedestrian space in order to realize a public space that can ultimately improve the quality of life based on guaranteeing people's right to move while also enhancing urban activity. The goal of this study is to develop a pedestrian path evaluation system in order to lay the foundation for data construction leading to the creation of such elegant walking space. First, a basic system was established in keeping with factors and the space, and this system was used as the basic framework of the study. The trends identified in the literature can be divided into eight categories, denoted here as: Walking safety policy, Walking focused plan,Recognition transition, Transportaion system, Activity-linked walking, Facility utilization walking, Nature and history linked walking and Content convergence walking. The macro- and micro-indices and factors mentioned in related studies were synthesized and classified, and the basis for universality and differentiation was established by integrating them. Next, according to the basic composition of the walking system, Walking potential and slope safety in the Safety category, Basic walking connectivity and Trafficlinkage in the Efficiency category, Walking arrangement and Rest convenience in the Health category, and Resource connectivity and Activity abundance in the Comfortability category macro evaluation system of the eight categories were established and acorresponding measurement method was developed.

사회 안전인식에 따른 지방자치단체 신뢰도 영향요인 분석 Determinants of Trust in Local Governments - Focusing on Risk Perception

https://doi.org/10.12652/Ksce.2022.42.4.0591

이윤주(Lee, Yun Ju) ; 최열(Choi, Yeol)

As social anxiety is increasing due to the spread of the COVID-19 epidemic, the responses at the level of local governments arealso changing depending on the characteristics. We analyzed the factors influencing perceptions of social safety as they relate to the trustworthiness of local governments. Based on a 2020 social survey of 16 cities, counties, and districtsin Busan Metropolitan City, theeffects of householder characteristics, economic characteristics, local attachment characteristics, and socialsafety perception characteristics on the reliability of the local government were analyzed through an ordinal logistic regression analysis. It was found that the more vulnerable the class was and the safer the region was, the higher the trust was in the basic local government. In order to respondand preemptively recover damage in natural and social disaster situations, continuous efforts are needed to strengthen the capabilities of basic local governments.