In this study, concrete slab with insulation and non-insulated formwork was used to monitor and control its strength using a wireless sensor network with equivalent age method. As a result, the temperature and compressive strength of the structures were monitored without any problems, which revealed a good management tool.

Concrete residential structures are being redesigned for maximum space utilization efficiency by including parking lots and other convenience facilities. However, there are increasing problems of leakage due to various environmental and deterioration conditions. This paper proposes the a world-wide-web based professional information sharing system designed to provide solutions, alternatives and technical information for leakage prevention and effective design at the beginning of the construction stage.

Because of the characteristics of long-span bridges, the cable tension is considered a critical item in their maintenance. In particular, because the evaluation of the cable tension in a suspension bridge is essential for understanding the general status of the structural system, identifying the initial values of this force in the construction of a bridge and then accurately predicting and comparing its estimated values during traffic use are very important tasks for the maintenance of a suspension bridge. In this paper, to verify the algorithm for estimating the cable tension of hanger cables using the back analysis technique, an ambient vibration test was conducted at a suspension bridge.

This study provides a simple introduction to photo-catalyst technology to degrade the air pollution in urban environment, in particular, NOx gases from automobiles. Moreover, it shows the spray coating technique was applied to effective coating on the surface of asphalt roads by using as-developed integral photocatalyst solution. In order to examine the slip resistance of asphalt surfaces, the BPT (British Pendulum Test) was used under drying and wetting conditions.

In many climatic conditions, there is UV ray, which is called ultraviolet rays, which has the greatest effect on sealing materials. Because UV has high energy, it changes the internal structure of polymer and causes quality deterioration. In addition, temperature, humidity, and rainfall, snowfall, and atmospheric pollutants are also factors to be avoided in maintaining the integrity of the sealant. In this study, we tried to obtain reproducibility by using a composite deterioration test device which can describe the environment of the outside air as a part of the research project to investigate the weather change in the prototype of the structural sealant. The outdoor exposure test result and the composite deterioration test device Correlation analysis. In the future, it will be possible to predict the changes in the physical properties of the structural sealant by applying the composite deterioration test equipment and outdoor exposure test data.

In this study examined the strength of wall concrete using insulated molds and non-insulated forms by monitoring the strength of the structure using a wireless sensor network by maturity method. It was confirmed that the temperature and compressive strength of the structures are monitored in real time, along with effective strength control.

This study is a case of construction after bridge demolition due to the aging of bridges operating the railway. Due to the influence of the pier vibration on the railway, the influence of the railway line, the construction period, etc., the P.B.S technique was applied to the coping pile foundation. It was completed in 5 days per 1 bridge pier by the PBS method. Since it is constructed in the dry season (from October to April) without vibration and noise, it can be installed safely on the rail rail of the pier of the bridge .

This paper analyzed design bearing capacities of pile foundations strengthened by pre-loading method for vertical expansion. The bearing capacities were investigated for two different pre-loading strategies: (1) after partial removals of structural/non-structural elements (e.g. finish, masonry wall etc.); and (2) after vertical expansions. Based on the numerical studies, more than 60% of the existing piles exceeded the design bearing capacities due to the difference of pre-loading strategies, which should be considered in structural design.

In this study, a nonlinear analysis method was proposed to investigate serviceability of rail fastening system in concrete track at the railway bridge end. The serviceability investigation method of the fastening system in concrete track is time consuming and is complex in design because of the many decks and fastening systems. In addition, there is also a case where an expensive special fastening device is installed due to the stiffness of the rail fastening device assumed to be linear and the excessive design result by the linear analysis method. Therefore, in this study, the clamping force test was performed to confirm the nonlinearity of fastener. The conventional linear analysis method and the proposed nonlinear analysis method were performed for the railway bridge model specimen with concrete tracks, and the uplift forces acting on the fastening systems were compared and analyzed.

This paper presents the application of meso-scale finite element analysis method on concrete split tensile strength. Using the meso-scale finite element analysis, an analytical study on split tensile strength of concrete was conducted. From the analysis results, the size effect on split tensile strength was confirmed.

Void slab is a slab with hollow portions in the center of the slab which reduce a self weight of the slab. The flexural capacity of void slab is almost same with a normal slab, but the shear capacity is reduced according to the increasing of hollow portion. One of the solutions to improve shear capacity is using shear reinforcing bars. In this study, the shear capacity of one-way void slabs is evaluated according to an effective cross section and the capacity of shear reinforcing bars is discussed depending on integration method. As a result, it is shown that the shear capacity tends to be reduced from 0% to 34.5% of hollow rate and slightly increased from 34.5% to 40.0%. And the capacity of integrated shear reinforcing bars are better than the one without integrated shear reinforcing bars.

This paper deals with the H.A.S. method, which is the non-open excavation method by using steel pipe jacking method. In order to determine the lateral optimal placement of the support during the internal excavation, the commercial finite element program was used to analyze.

In this research, new structural design and manufacturing method of atypical irregular UHPC structural members were newly introduced. The atypical irregular UHPC member was optimized to design from the conventional rectangular section and a method of nonuniform formwork system was newly created to manufacture the irregular member. The specimens were evaluated by analysis and the newly designed member was improved in bending performance by 2.6 times compared to conventional rectangular concrete beams.

The river levees along the state owned rivers or local rivers are a major infrastructure of the nation, and it is necessary to be able to quickly and accurately evaluate the safety of each structure in case of a disaster such as flood or earthquake, so as to enable preemptive disaster response. In this study, a “real-time safety assessment method of river levees” was developed to understand the safety of river levee in real time and cope with disaster situations preemptively and effectively, and its applicability was examined. The real-time safety evaluation method of the river embankment developed in this study is based on two systems; ① real-time monitoring system by instruments and ② safety evaluation DB system of river embankment based on fragility curves using numerical analysis results. In order to validate its applicability, the safety of Munsan levee located in the upstream area of Kangjeong-Goryeong Weir was evaluated by applying the proposed method.

In this study, the 3 point-bending test was performed on the RC T-beam and the image processing method was used to analyze the change of curvature according to the step of loading. As the loading step progressed, the bending deformation and inflection point of curvature by shear cracks occurred. It will be possible to evaluate the detailed behavior of the RC structure by using the image processing method used in this study.

There are weaknesses of water-pipe buried at river because of difficulty like to invisible exposure by scour. These weaknesses cause flotation, deformation and damage of pipeline. Therefore, this paper presents the survey instrument applying GNSS that KISTEC has recently introduced. Also, we has verified reliability by discovering exposed water-pipe on field

Hydrologic and Physicochemical properties are the properties of water, defined by physicochemical properties such as water temperature, electrical conductivity, pH and the concentration of inorganic ions. Although it is difficult to directly identify the cause of seepage through hydrologic and physicochemical analysis, it can be used as indirect data to estimate the origin of leakage.

Recent earthquakes in Gyeong-ju and Po-hang have raised concerns about the safety of nuclear power plant structures. In particular, there is a demand for a technique for detecting and evaluating the deterioration that occurs in the concrete which is inaccessible after curing. In this paper, we propose a method for evaluating the reliability of concrete detection equipment using ultrasound, as the ultrasonic tomography technique has been attracting much attention with the detection technique of the inside of concrete.

수공구조물 설계시 실측 유량의 자료 부족으로 홍수량의 빈도해석 결과보다는 강우자료를 수집하여 강우-유출 관계에 따라 산정된 설계강우량을 이용하여 특정 빈도에 해당하는 설계 홍수량을 사용하는 것이 일반적이다. 과거에는 첨두유량 산정을 위하여 합리식과 같은 경험식을 이용하였으나 지속기간이 장기화됨에 따라 실제 사상과는 다른 유출양상이 나타나게 되므로 확률강우량 시간분포의 정확성이 중요하게 되었다. 현재 실무에서는 설계강우량의 시간분포 방법으로 Huff의 4분위 방법 중 3분위를 사용하고 있으며 분위별 곡선에 대한 회귀식은 지속기간 전반에 걸쳐 정확도가 높은 이유로 6차식을 적용하고 있다. 그러나 통계 모델링에서는 간결함의 원리에 따라 회귀식이 간결할 필요가 있으며, 통계적 유의수준에 기초하여 회귀계수를 결정할 필요가 있다. 따라서 본 연구에서는 기상청 관할 69개 강우관측지점을 대상으로 설계강우량의 시간분포 방법으로 사용되고 있는 Huff 4분위 방법의 시간분포 회귀식에 대한 유의성 검정을 실시하였다. 기상청 관할 69개 강우관측지점의 Huff 4분위 방법의 시간분포 회귀식의 유의성 검정결과 대부분의 지점에서 4차식까지 회귀계수가 유의한 것으로 나타나 통계학적으로 Huff의 4분위 방법의 시간분포 회귀식은 4차까지만 고려하여도 무방한 것으로 분석되었다.

본 연구에서는 TS 내진보강공법의 내진보강 효과 검증을 목적으로 7개의 지진파에 대한 TS 댐퍼(Tension Spring-Damper)로 내진보강된 구조물의 비선형 시간이력해석을 수행하였다. 비선형 시간이력 해석을 통해 얻어진 무보강 구조물의 층간변위비와 에너지소산 양과 비교한 결과 층간변위비가 약 30% 가량 감소하였고, 구조체를 통한 에너지 소산의 양은 반감되었다. 이를 통해 TS 내진보강공법의 제진성능이 우수함을 확인하였다.