There are many cases where large areas of the underground parking lots of residential buildings do not have proper measures against prevention of leakage, resulting in condensation, growth of infectious microogranisms and increase of pollution in the air. This paper discusses a study conducted to understand the awareness of leakage problems and the damage that follows in the underground structures of residential buildings.
This paper aims to develop a wireless unified-maintenance system(WUMS) to obtain real-time structural response of civil structures. The WUMS integrates the GPS module, the strain module and the acceleration module based on the standalone controller, and includes the RF module for remote measurement and the battery for long term operation. In order to evaluate the performance of the WUMS, a response test using a modal shaker and a modal test using a model bridge were performed. The test results using USMS were compared with those measured by wired system. Finally, the developed WUMS was appropriate to obtain the structural response of the civil structure in real-time, unified, and wirelessly.
The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification
In reinforced concrete structures, carbonation phenomena associated with deterioration is important. So, this study conducted a visual inspection and a concrete durability test in Precise Safety Diagnosis, analyzed the result, and tried to suggest a reasonable repair method and range of concrete carbonation.
When reinforcing an existing reinforced concrete beam-column building with a precast concrete panel, special connection between the PC member and the RC member is required to solve the time dependent deformation of the RC member and to receive the large shear forces. The aim of this study is to obtain the shear strength of upper connection between the existing RC beam-column and infilled PC wall panels in experimentally and theoretically. Thus, the static shear loading tests were conducted on the 6 specimens with the plate connection. Shear failure was resulted from the weakest portion of interior PC panel, exterior RC, and the connection, when the PC portion which located at the center of specimen was pulled upward from the bottom. The experimental result was compared with analytical result from ACI 318M-14 Chapter 17 for the shear strength of post-installed anchor and PCI Handbook 7th edition 6.8 Structural Steel Corbel (PCI Design Handbook 7th edition, 2010) for the strength of cast-in H-beam. The analytical and experimental results show final failure at the same location. The failure loading of experiment showed larger than average 6% to that of the analysis.
This paper addresses simplified method for nonlinear soil–structure interactions (SSI) analysis of base-isolated nuclear power plant (NPP) structure under incident seismic waves. The accuracy and applicability of the method are evaluated by comparing with nonlinear time history responses obtained by the boundary reaction method (BRM).
This study proposed a seismic isolation system which uses the LM guide featuring high hardness and low frictional coefficient and a viscoelastic damper possessing high restitution force and damping force in order that existing seismic isolation systems using conventional sliding bearing way can be applied to a structure, and intended to analyze the proposed seismic isolation system's utilization possibility as a seismic isolation system for rescue through an experiment utilizing 6 earthquake waves being entered according to the reoccurrence cycle on the basis of performance-based design, and the case of Kyungju earthquake and to interpret the results of experiment.
This study evaluates seismic risk of steel ordinary concentrically braced frames. Based on the risk integral concept, the collapse probabilities in 50 years are calculated for the 3-, 5- and 10-story braced frames. The evaluation results present that the collapse probabilities in 50 years are increased for the higher braced frames although they are identically designed according to the current domestic seismic design code.
In this paper, we research about integrated jacket support structure. The connection of the offshore wind support structure was designed based on the DNV-RP-C201 standard and the design of the appropriate type was derived through numerical calculation and finite element analysis of the stress paths of various connecting part type.
All the structures include initial imperfections that can affect the structural behavior and stability, particularly during construction. Therefore, for a concrete beam with an initial lateral deformation, creep analysis was performed to evaluate the influence of the initial imperfection on the creep deformation of the beam in the both vertical and lateral directions.
In this study, a drone based structural health monitoring technique is introduced which uses a piezoelectric (PZT) transducer attached to a drone. With the PZT transducer, the electromechanical impedance (EMI) method is modified to be attached and re-attached onto a structure for damage identification. Since one of the possible principle technology is to keep the tube structure safe from damage, the idea introduced in this study opens up new possibilities of monitoring the integrity of the Hyperloop structure.
Due to limited human resources, budget and difficulties in accessibility, inspections are not available at proper time. Advanced Technology such as ICT, Sensing, and AI can innovate the management of structure. So, we introduce our developed equipment and future management plan.
The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we developed a smart checking system to evaluate the stability of the corrugated steel plate culvert structure by laser scanning and image mapping. It is expected that output data can be used in inspecting deformation rates between designs and measured 3D shapes. Also, it can solve the problems in current visual inspection and systemize the inspection tasks scientifically.
Concrete structures built by 3D printing technology is formed as the several concrete layers. Thus, 3D printing technology for concrete structure could have less strength than the design. In this study, fracture energy (fracture toughness) tests for layered concrete in various condition was performed. depending on required time for stacking new layer. Based on the results of performed tests, it was found that fracture energy was decreased due to increased non-bonded time.
In this study, cement mortar (KS F 4042) used for repairing concrete structures was evaluated for compressive strength and bond strength according to the mixing ratio of polymer. From the experimental results, it was confirmed that as the polymer content increases, the bond strength properties increase, but the compressive strength decreases slightly at a certain rate.
We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.
We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.
This study is a part of the research on the development of safety monitoring system and monitoring program of 3MW offshore wind support structure using fiber optic sensor. In this paper, we propose a maintenance system for offshore wind support structure using fiber optic sensor based on the analysis of current monitoring status and related standards of domestic and overseas offshore wind support jacket structures.