This paper propose to make a Construction site safety management system using beacon indoor positioning technology. in this system, as using beacon, it can measure the position of worker who have smartphone or any device which have bluetooth function. there is two way to use technology of beacon, first one is distance technology which can alarm dangerous situation such as appoaching heavy equipment. second one is location positioning technology. it is the main technology which can measure the position of workers in real time. this system is based on low energy and accurate sensor, beacon, and have a low cost advantage. so it is expected to improve safety on the construction site.

It is necessary to develop the damage function to cope with the increasing damage of steel transmission towers. A simplify analysis to evaluate the performance resistance capacity, which is essential for the development of the damage function, was performed. The 154kv power transmission towers installed between Sokcho and Yangyang were selected as the target structures. Wind loads were calculated and applied to the target structures according to the domestic transmission and distribution facility design standards. As a result of this study, displacement according to wind speed of the target structure was derived.

The purpose of this study is to provide client safety and health management duty in the construction industry. Most regulations did not give direct roles and duty to client in construction industry. As a result of the survey on construction workers who have the greatest influence on the prevention of industrial accidents, the clients and constructors chose contractor the most. Safety managers and supervisors chose client the most. Therefore, it is necessary to manage safety and health centered on the client in order to prevent fundamental disasters.

The purpose of this study was to evaluate the tensile fracture behavior of fiber hybrid reinforced cement composite according to the strain rate. Experiment result, it was confirmed that the number of cracks and the strain capacity tended to decrease with increasing PVA fiber volume fraction at the strain rate of 101/s.

It has been many studies and technical developments of recycled aggregate for concrete, but some limits due to lacks of quality control and reliability. Thus, this study addresses to find real problems in using recycled aggregate for concrete through questionnaire. It is known that first of all, proper grades of commercially available recycled aggregate shall be necessary to produce proper and economical concrete.

To provide the pleasant residential environment, the concern for the noise of concrete pile has increased at construction site. In this study, the noise characteristics of non-noise pile driving method by scale model were compared when the noise breaker was applied. From the test results, the noise characteristics are affected by the noise breaker

Due to recent climate changes, damage to the soundproof wall due to typhoons and strong winds is on the rise. This study determine the fragility curve of aluminum frame, which is a weak member of the soundproofing wall, due to strong wind. The fragility was analyzed in term of aluminum frame thickness variation. Finite element analysis of the wall was performed with ABAQUS, a commercial program. Random wind loads applied to the structures were generated using the Monte Carlo simulation technique. Also, the limit state was set based on the analysis results. The fragility curves were developed with consideration of three influential factors which are installation location, wind exposure and thickness aluminium frame of soundproof wall.

The purpose of this experimental study is to investigate the application of materials of construction using TiO2. The functional Al2O3-TiO2 carrier powder was fabricated by sol-gel method, this is mixed in a cement mortar. As a result, compressive strength of mortar using Al2O3-TiO2 powder was confirmed to be superior than mortar using ordinary TiO2.

According to this study, small-scale construction projects with a construction value of less than 300 million won are placed in the blind spot of safety management inspection. Therefore, it is necessary to improve the management and inspection system that reflects characteristics of small-scale construction sites.

In this paper, the shear performance of the deep beams with high strength headed reinforcement was evaluated. The experimental parameters are horizontal stiffener and fusing length. The shear span-depth ratio (a/d) of specimens was 1. The development length of headed reinforcement was evaluated to have a great influence on the shear strength of the deep beam.

Recently, the use of duplex stainless steel which has a two-phase microstructure consisting of grains of ferritic and austenitic stainless steel has been increased in a variety of industrial fields. Especially, STS329FLD with lower nickel content and higher yield strength compared with austenitic stainless steel has been developed. In this paper, experiments have been conducted to investigate the structural behaviors of single shear duplex stainless steel(STS329FLD) bolted connection with four bolts. Specimens with relatively long end distance failed by block shear fracture accompanied with curling (out-of-plane deformation) and the curling reduced the ultimate strength.

In this paper, block shear fracture behavior in base metal of fillet-welded connection fabricated with duplex stainless steel (STS329FLD) were investigated through experimental procedures. Main variables are weld lengths in the longitudinal and the transverse directions of applied force. As a result, test specimens failed by typical block shear facture (the combination of tensile fracture and shear-out fracture) in base metal not weld metal. Ultimate strength of the specimens tended to get higher with the increase of the weld lengths.

In this paper, the flexural test of concrete member damaged due to Calcium leaching were performed to evaluate the characteristics of structural behavior. From the results, yield load, maximum load and flexural rigidity of RC member damaged by calcium leaching were decreased and the depth of the neutral axis was increased.

The purpose of this research is to develop a joint system for two concrete pipes with reduced wall thickness by a carbon fiber reinforced polymer (CFRP) fabric. As compared to conventional concrete pipe, the concrete pipe with the reduced wall thickness has more flexibility. However, the reduced wall thickness makes the conventional joint system not feasible. As an alternative joint, externally wrapping system with the CFRP fabric was proposed. The two CFRP widths (75mm and 150mm) were accounted for as a variable under joint shear test from ASTM C497M specification. The externally wrapping system showed 81.07% higher shear strength, as compared to the required shear strength by ASTM C497M.

According to social needs, eco-friendly material for concrete structures has been developed in recent years. Hwang-toh is one of the eco-friendly architectural material and hwang-toh has been used by partial or complete replacement of portland cement. Four beam specimens with the variations of types of FRP bar (GFRP or CFRP bar) and cement are prepared and tested. From development test, the performance of FRP rebar for PVA fiber reinforced AHC was evaluated.

The purpose of this study is to evaluate the effect of steel fiber reinforced concrete on structural performance when applied to joints. For this purpose, the development length was designed not to satisfy the concrete structure criterion. Experimental results show that the maximum strength of steel fiber reinforced concrete increases by about 12% in the direction of the settling force. Also, due to the increase of the tensile strength of the concrete, the strength of the cracks increased by 33% in the positive direction.

Recently, as the awareness of safety has become more important, studies on damage assessment techniques for building structures have been actively conducted. The damage of the building structure is caused by the decrease of the stiffness which is inherent dynamic characteristic of the structural system, and the decrease of stiffness acts as a direct variable connected to the collapse of the structure. there have been developed techniques for estimating the inherent dynamics of a structure to identify and evaluate damage to the structure. In this study, we estimate the layer mass due to the modeling error through the optimization algorithm, Genetic Algorithm, and use the optimization algorithm GA to optimize the error covariance matrix, system noise and measured noise covariance matrix We propose an optimal state estimation algorithm. The objective function of the GA algorithm is obtained by the residual which is the difference between the measured values obtained from the EKF calculation and the values obtained from the system model. We verified the feasibility of the algorithm through a 4-DOF system.

The study was conducted to determine the structural optimization method through the estimation of the structure of the floor and the amounts of reinforcement in the apartment building and the amounts of reinforcement depending on the area. The purpose of this study is to examine the comparison of the comparison factors by comparing the comparison factors of the jointly constructed apartment house with each of the conditions.

Since power plants are primarily using seawater as cooling water, they have been severely damaged quite often by various marine organisms inflow in power plants. So, various screen system - bar screen, travelling screen, drum screen and debris filter - have been used as a facility preventing harmful substances into the water intake of power plants. However, it is not enough to prevent too small organisms such as krill shrimp and large mucilages such as jellyfish. Therefore, it is necessary to study the screen system that can prevent harmful substances more efficiently. In the present study, the principal and shape of a air bubble barrier system was proposed as a screen system for preventing harmful substances. Then, analytical studies were carried out to evaluate environmental loading acting on the barrier structure.

This study evaluated displacement of ceiling system under lastic dynamic load. Main parameters are change of stiffness at connections of bolt and C channel ranged between 0.1~2.0 kN/mm. Program for elastic dynamic anaysis is the MIDAS ZEN. Analysis results showed that connections between bolt and C channel was effective on decreasing of displacement of ceiling system.