Pipe line for the water supply and/or drainage is one of the most important life lines which is usually suffered from the damage due to exterior load induced deformation and due to the lack of support resistance provided by the surrounding soil. GFRP (Glass Fiber Reinforced Polymer Plastic) pipes are generally thinner, lighter, but stronger than the existing concrete or steel pipes, and it is excellent in stiffness/strength per unit weight. In this study, we present the result of field test for buried RPMP (Reinforced Polymer Mortar Pipe) and RTRP (Reinforced Thermosetting Resin Pipe) pipes with 2,400mm diameter. The vertical and horizontal ring deflections are measured for 387 days. The ring deflection of RPMP and RTRP measured by the field test is compared with the ring deflection limitation (5%) according to ASTM D 2412.

본 연구에서는 개별요소해석 프로그램인 PFC3D를 이용하여 지오그리드와 재료입자 사이의 상관관계를 지오그리드 반복인장 시험 및 전단시험을 통해 확인 하고자 한다. 재료의 입도 유효입경 D50 (누과통과율 50%)을 기준으로 40mm, 30mm, 20mm, 15mm, 10mm 로 비교 하였고, 합성수지로 제작된 지오그리드 개별요소를 미시 물성치 보정을 통해 형성하였다. 반복인장에서는 변형률 0.5%를 최대 인장 변형률로 설정하여 반복인장을 500회 실시 하였으며, 전단 시험에서는 지오그리드 생성위치를 전단면으로 설정하였고 횡방향으로 변형률 10%까지 전단시켰다. 해석 결과 유효입경 20mm에서 가장 큰 보강효과를 확인 하였고, 40mm 및 30mm에서 보강효과가 감소되는 것을 확인하였다. 지오그리드의 격자 크기를 고려하였을 때, 재료의 유효입경의 크기는 격자의 내접원 직경의 60% 정도 확보 시 보강효과가 가장 좋은 것으로 확인하였다.

Generally, antiseptic synthetic woods are used in septic environment because of their durability and relatively fine view. However, they have problems such as a failure of connection between the members under the septic conditions. In this study we investigate a fiber reinforced polyurethane foothold to be used in the wet environment to replace the synthetic wood. The fiber reinforced polyurethane foothold is consist of 2 different layer of materials. First layer is a glass fiber reinforced polymeric plastics (GFRP) which is located at outer surface of the foothold. This GFRP outer layers carry most parts of load. Second layer is a polyurethane layer which transfers the load to each outer layer. Flexural tests for this foothold are conducted. From the flexural tests it is confirmed that the structural performance of foothold test specimen with different number of GFRP layers and density of the polyurethane.

In the water supply pipeline system polyethylene (PE), polyvinyl chloride (PVC), and ductile cast iron pipe are mostly used. However, they have some problems such as reduced durability due to material degradation, defects in connections, the pipelines breakage, and lack of continuous maintenance. Recently, research on durable and outstanding corrosion resistance glass fiber reinforced polymer plastic (GFRP) pipe is being actively conducted. GFRP is classified into the flexible pipe and when soil pressure and live load act on buried GFRP pipe, the load acting on the pipe is transferred to the surrounding soil. So, pipe will support the load with the surrounding soil. In this paper, to apply GFRP pipe for the water supply pipeline system, the structural reliability of GFRP water supply pipe buried underground should be investigated by examining the mechanical properties of GFRP pipe as well as the soundness of the pipe under buried state. The field test of buried pipe is conducted and the results are analyzed and discussed.

Axial force of the bolt is very important for structural stability. To obtain stability of the structure, axial force of the bolt should satisfy the specification and be maintained over the time. Hence, It is important to the axial force of the bolt is measured and it manages. However, measuring of the axial force using sensors is very expensive. Torque method using frequently in the field is difficult to confirm accurately by the torque coefficient change. In this study, measuring of axial force using elastic force of the spring washer was studied. First, the relational formula is drawn about the pressure in which the spring washer model changes to the annular of the plane state. According to the axial force of the bolt, the necessity height of the spring washer is presented and the finite-element analysis model is recommended. The analysis model research, generally, the axial force of high strength bolt is confirmed. It expands to confirmation of the large caliber bolt.

This paper presents an experimetal study on RC beam strengthened with 3D Ultra-High-Mocular-Weight-Polyethylene (UHMWPE) fabric. This research program aims at developing the 3D UHMWPE textile fabic to improve the structural performance of RC beam. Specimens were constructed and experimentally investigated through static tests. Testing data were analyzed to investigate the performance of the specimens retrofitted or strengthened with UHMWPE fiber compared to the non-retrofitted RC beam responses. It was concluded that the strengthening method using 3D UHMWPE fiber can improve the performance of RC beam.

In the water supply pipeline system, pipes made by cast iron, PE, PVC are generally used. However, the structural performance of these materials can be declined when used for long periodsof time because of corrosion, creep, deterioration of the material, etc. while glass fiber reinforced polymer plastics (GFRP) have many advantages such as light-weight, corrosion resistance, smooth surface, etc. For these reasons, GFRP pipes are good for construction when it is buried underground and are increasing trend in applying the water supply pipeline system. Therefore, more optimized structural design methodology should be developed. In this paper, we confirm pipe stiffness (PS) of GFRP pipe in which the pipe stiffness indicates the load-bearing performance. We compared data of parallel-plate loading test and theoretically predicted PS by the classical elasticity theory and the finite element method (FEM).

In this study the structural performance of new composite column to composite beam connection was evaluated by cyclic tests. It is designed to be applied to various types of through type system to the bottom plate to view synthesis composite beam. A composite column is composed of a RC type column reinforced by steel angles which the end bends in each edge corners of column. also, A composite beam is composed of trussed type’s web, a bottom steel plate and reinforced by steel angles which the end bends in each edge corners of beam. 4 cyclic tests of the clarified structural performance of the connections are performed. All specimens that is apply reinforced concrete beam-column joints based on KBC2009 criteria was performed by cyclic test of column to beam. All specimens were exposed to be satisfied with the required ultimate strength.

Deep-Deck usually used in long span structure for its larger section properties. but Deep-Deck has difficulties when the span is over 9m because of deflection. Deflection makes workers anxiety and Structural problems. So, Preload is used to the Deep Deck To control the the deflection of the deep deck which has 9m over. In this study, The Preloaded deep deck which has 9m was evaluated by Experments. Result of experiments, preloade and camber have proportional relation

This study performed an inverse detection of fiber stiffness degradation that occurs due to damages in free vibrating composite structures. Five unknown parameters are considered to determine the fiber stiffness which is a modified form of the bivariate Gaussian distribution function. The proposed approach is more feasible than the conventional element-based damage detection method from the computational efficiency because a finite element analysis coupled with a genetic algorithm using a small number of unknown parameters is performed. The numerical examples show that the proposed technique is a feasible and practical method, which can prove the location of a damaged region as well as inspect the distribution of deteriorated fiber stiffness although there is a small difference in dynamic characteristics between damaged and undamaged structures.

This study investigates the analytical study for evaluating impact resistance capacity and failure mode of PROTECT (Poly-Resilience-Oriented hybrid TEChnology plaTe) panel. PROTECT panel is a composite panel with two steel plates and nano-composite. In order to perform impact analysis, dynamic properties of steels and nano-composite were determined. Finite element analysis is performed with these properties under the drop-weight impact. From the FEA, different failure modes corresponding to different impact energy is derived.

The geotextile tube’s performance in strength, dewatering, retaining solid particles and stacked stability have been studied extensively in the past. However, only little research have been done in the observation of stress behavior of geotextile tubes. In this paper, a large-scale apparatus for geotextile tube experiment is introduced. Model tests was conducted using a custom made woven geotextile tubes. Load cells placed at the inner belly of the geotextile tube to monitor the total soil pressure. The pressure sensors are attached to a data logger which sends the collected data to a desktop computer. The experiment results showed that the maximum geotextile the soil pressure distribution varies at each geotextile tube section.

The load-end slip relation of the steel-concrete decks is formulated by Newmark theory. Using the proposed load-end slip relation model, a simple bond model, which can be used to evaluate the behavior of the steel-concrete decks, is proposed. The steel-concrete decks are analyzed by finite element analysis with the aid of the proposed bond model. In the finite element analysis, the shear connectors between the steel plate and the concrete are modeled by a number of spring elements. The results of the finite element analysis with the proposed bond model are fairly correlated with the experimental results of the full-size model. This study furthermore indicates that, if the proposed bond model is properly used in the analysis of steel-concrete composite deck, the behavior of the composite deck can be easily analyzed without the aid of the full-size experiment.

Grouted connections have been widely used for offshore structures such as connection method of jacket and mono-pile structures. It is recommended high strength concrete for grouting between pile and sleeve because it is so rapidly hardening that helpful to fatigue strength. This study investigates axial strength of pile to sleeve grouted connections made by 130MPa of high strength concrete. Push-out test were performed to evaluate the axial strength of the grouted connections with different shear-key spacing.

Pultruded fiber reinforced polymeric plastic (PFRP) has many advantages such as high corrosion resistance, high specific stength/stiffness, light weight, etc. Pultrusion is a manufacturing process for producing continuous lengths of reinforced polymeric structural shapes with constant cross-section. The mechanical property of PFRP is usually regarded as an orthotropic material. The pultruded structural shapes are usually composed of thin-walled plate element. Because the composite material has relatively low elastic moduli, the design of pultruded compression members may not be governed by the material strength limit state but by the stability limit state such as the local buckling. Therefore, the stability limit state must be checked to design pultruded thin-walled compression members. In this paper, we present the analytical study results of elastic buckling strength of PFRP orthotropic plates with different fiber volume ratios. The local buckling analysis of pultruded compression members was conducted for various composite materials using the closed-form solution. From the study it was found that if E11/E22 is increased then the plate buckling coefficient, hence the plate buckling strength, is decreased.

The experimental study aims to investigate uniaxial behavior of ultra-high-performance fiber-reinforced composite (UHPFRCC) columns with compressive strengths of 180, 150, and 120 MPa. Eleven square columns and six circular columns will be constructed and tested with uniaxial load. Main variables were the amount and spacing of transverse reinforcement, and concrete compressive strength. The amount and spacing of transverse reinforcement were chosen based on the seismic design provisions of ACI Code (ACI 318-14) and CSA Standard (CSA 2014).

This study investigates the analytical study for developing PEB(Pre-Engineered Building) connection Steel damper. The state-of the art of the steel beam-column seismic connection details were studied previously to develop proper damper for PEB connection. Finite element analysis is performed to develop the prototypes of damper under cyclic load. The study parameters of analysis are the shape, length, thickness, orientation and location of damper. As a result of finite element analysis, three prototype damper details for PEB seismic connection are derived. One is tapered plate on the lower flange of the rafter, another is C-plate on the center of panel zone and the other is brace on the beam-column connection.

This study describes the seismic performance evaluation of bridge structures located in Daegu. Structure design criteria focuses on the collapse or brittle fracture of the bridges when the earthquake situation is given. Thus, this study describes the seismic safety evaluation based on the design of a spectrum of ASCE-7 KBC2009 of the United States, South Korea architectural structure was based on using 3D linear elastic finite element model using the ABAQUS platform bridges. If the target structure was found to be vulnerable to tensile stress than compressive stress appeared to be a case of displacement Z-axis displacement is dominant.

This research presents assessmental FRP plate, one of materials used for reinforcing damage of RC structure caused by deterioration. in order to investigate effective bonding length and bonding strength according to material property of epoxy used for bonding between FRP-Concrete, experimental tests for 3 specimens with each bonding length of 50,100,150,200and 250mm respectively are performed. test results indicate frat material property of epoxy can affect effective bonding length of FRP-Concrete.

Deep Deck plate is suitable to long span structures because it has larger flexural rigidity than other shape deck plate. but Deflection is critically proportional to span length than other factors. and large deflection makes works anxiety and possibility of structural problems high after casting concrete. to overcome these problems, Preload is introduced to control the deflection of deep deck plate that ha s long span. So in this study, residual strength of preloaded deep deck plate is evaluated by FEM analysis method. for this study 4 analysis models is used and have each preload. Target preload for analysis models is when deck plate cambered to 30mm. 0.0, 0.8, 1.0, 1.2, times of target preload are applied to each analysis models. In result of analysis, Preload influence residual strength of deck plate. And much preload degrade strength of deck plate.