As the pilot study on textile reinforced mortar(TRM) construction method, the present research has been conducted to investigate the tensile performance of fiber-reinforced polymer(FRP) grids inserted in inorganic mortar. For this purpose, experiment was carried out using twenty specimens with the main parameters of inorganic mortar and FRP grids. As a result, splitting failure did not occur between inorganic martar and FRP grids. As FRP grids were completely fractured, the specimens failed by showing the similar tensile behavior to the mechanical properties of FRP grids.
In this study, the retrofit effect of fiber reinforced plastics (FRP) jacketing by optimal algorithm for the existing reinforced concrete (RC) moment frame is investigated. FRP based retrofits are applied to both columns and beams in RC frame, simultaneously. The amounts of FRP reinforcements according to the retrofit positions are independently determined by the genetic algorithm based optimal method The amounts of FRP reinforcements and the collapse probability are considered by using the objective functions.
This study is to evaluate the enhancement of steel pile in terms of performance when reinforced by primer and impregnated epoxy developed for underwater. Through compressive strength test, the adhesion between original material and new one was to be investigated as well as reinforcing effects.
Recently, the FRP known to be new material for repair and rehabilitation has several deficiencies even lots of advantages itself, especially underwater construction. By evaluating the material properties of FRP for underwater, thus, this study provides construction technology with basic data related to repair and rehabilitation of structures submerged in the water.
Shear capacity of a Textile Reinforced Concrete (TRC) was investigated by an experimental study. Control beam (unstrengthened) and eight beams strengthened with TRC were fabricated to confirm the reinforcing performance in this study. Test variables considered the number, width, spacing of TRC, and reinforcing method accordance with type of attachment. As a results, it was validated that the shear capacity of beams strengthened with TRC in comparison with unstrengthened beam increased from 11.4% to 54.3% according to the amount of TRC. Experimental results indicated an increase in both load carrying and deformation capacities, and also ductility when using multiple layers of textile.
The purpose of this study is to assess the strengthening effect of fiber-reinforced polymer(FRP) grids on flexural members. For this purpose, experimental study was conducted using seven flexural specimens with the main variables of an FRP grid and inorganic mortar used as adhesive. All the specimens failed due to the tensile rupture of FRP grids without debonding between FRP grids and inorganic mortar. It was found that the strengthening effect was dependent on the material properties of FRP grids.
Conventional approach for restraining additional lateral movement of bridge abutment is to decrease applied load by replacing rear ground with EPS block, ALC(autoclaved lightweight concrete), to increase soil resistance by applying tie-rod, geo-grid, permanent anchor, counterweight fill, and to increase lateral bearing capacity of soil by installing grouting, restraint pile. With properly restrained lateral movement of bridge abutment by applying those methods, the expansion joint and bridge bearing can be repaired after securing expansion joint gaps by cutting off concrete slabs and steel box girder. In this paper, the proposed approach for securing expansion joint gaps by restoring displaced bridge abutment to its original position with the use of hydraulic jacking device is discussed. By using hydraulic jacking device, cutting off concrete slabs and steel box girder is unnecessary.
Ballast track has been widely used because of convenient maintenance. However, ballast deterioration requires frequent maintenance due to increasing speed, weight, and traffic of trains. Fouling is known as deterioration and expedites irregular settlement. In this paper, non-destructive methods were applied and investigated in order to evaluate ballast conditions such as thickness of fouling layer. Ground Penetrating Radar (GPR) and Dynamic Cone Penetrating (DCP) Test resulted in reasonable detection of fouled layer.
In this study, to evaluate the applicability of VDMS(Vision-based Displacement Measurement System) in the field, 30m of real specimens were measured vertical displacement using the VDMS and a displacement Transducer. The VDMS was to take a picture by attaching Target on the structure. Then, by analyzing the video in Digital Image correlation algorithm obtained a displacement of the structure. The vertical displacement of 30m real specimens using the VDMS and a displacement Transducer was very similar, and it is determined that the VDMS has a high applicability in the field.
Based on the study of LOD for BIM when doing structural modeling. Divide and standards LOD criteria And investigates the characteristics of property which have to involve in structural analysis
Maintenance of facilities is also growing in importance with the increased quantity. In developed countries, it is trying to introduce the asset management of the facility. In addition, the Korea Accounting guidelines presents a valuation method for the facility.
In this study, we investigated the methods presented in infrastructure assets for accounting guidelines.
In this study, the image processing technique referred as night vision was introduced in order to measure the displacement of structure during the nighttime. The validation of the reliability and the applicability of proposed method was evaluated by the scaled model test.
To monitor static and dynamic responses of bridges, an image-based monitoring system using networking Pan-Tilt-Zoom IP (Internet Protocol) cameras has been developed. Verification testing is carried out during the human-excited vibration test of the stay cables in a cable-stayed bridge. As well as identifying the natural frequencies of the stay cable, the reasonable damping ratios are successfully extracted from the acquired images.
Due to expansion of service environments for the Jack-up barge, the design of the footing has been improved. In this paper, the structure analysis of the modified spudcan based on DNV-OS-C201 examples was assessed.
This paper introduces unfamiliarity index (UFI) that calculated from the FFT results of the short term timeline acceleration responses. If this algorithm, which can detect an abnormal behavior from the maximum constant signal, is used to the terminal sensors of an structure, more accurate safety control criteria will be prepared efficiently.
The probabilistic prediction method and procedure of ships traffic for reasonably considering the enlargement of ships and increase in the large vessels of the vessel were established in this paper. However the problem related on prediction method, confidence intervals and selecting the target tonnage considering the enlargement of ship for prediction of ships is lack of results such as design example and study case. Therefore it requires various methodological study.
Climate change and the frequency of natural disasters such as earthquakes are threatening dam safety. In order to carry out the high functions of reliability of the dam facilities, K-water is promoting the safety enhancement project of dams.
Measurement of dynamic displacement of large structure is one of the most challenging issues in structural health monitoring. With a Kalman filter based technique, the proposed displacement measurement system which consists of GPS-RTK, accelerometer, DAQ, and computer shows the huge potential for precise measurement of dynamic displacement of large structure. The performance of the system has been verified by modal shaker test. This paper presents a new system for dynamic and pseudostatic displacement measurement for a large-scale civil infrastructure. Even though dynamic displacement measurement on a large-scale structure is one of the most challenging issues in structural health monitoring, traditional displacement sensors as well as cutting edge noncontact sensors suffers from the lack of accuracy and precision due to field conditions such as measurement distance and requirement for a fixed support. With a Kalman filter based technique, the proposed displacement measurement system, which consists of a GPS-RTK, accelerometer, DAQ and computer, efficiently estimates bias contained in the acceleration record by fusing the acceleration with intermittently recorded GPS-RTK data, and estimate high precision and high accuracy displacement by removing the bias from the acceleration record and conducting double integration. Through a series of lab-scale tests using a vibration exiciter, the performance of the system has been verified and shows the potential for accurate and precise measurement of dynamic displacement of a large-scale structure.
The Ministry of Unification has published the North's social and economic indicators about 'North Main statistical indicators' every years. However, "North Main Statistical Indicators" does not reflect the status and the level of North Korean infrastructure. The purpose of this study is to survey maintenance status and level of North Korean infrastructure, and to propose a regional assessment results.
Development of performance evaluation method per unit facilities for the performance-based management·operation of the port facilities defined in the accounting process guideline for SOC facilities and verification of the practicability of the developed method.