• Wind and Structures
• /
• v.27 no.5
• /
• pp.337-345
• /
• 2018

Tall buildings are subjected to wind loading that can cause excessive wind-induced vibration. This vibration can affect the activities of the inhabitants of a building and in some cases fear for safety. Many codes and standards propose the use of curves of perception of acceleration that can be used to verify the serviceability limit state; however, these curves of perception do not take into account the uncertainty in wind-climate, structural properties, perception of motion and maximum response. The main objective of this study is to develop an empirical expression that includes these uncertainties in order to be incorporated into a simple procedure to evaluate the wind-induced acceleration in tall buildings. The use of the proposed procedure is described with a numerical example of a tall building located in Mexico.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.1
• /
• pp.99-109
• /
• 2012

This study aimed to develop a Structural Health Monitoring System for steel beams in the manner of suggesting and verifying a theoretical formula for displacement estimation using strain gauges, and estimating the loading points and magnitude. According to the results of this study, it was found that when a load of 160kN (56% of the yield load) was applied, the error rate of the deflection obtained with a strain gauge at the point of maximum deflection compared to the deflection measured with a displacement meter was within 2%, and that the estimates of the magnitude and points of load application also showed the error rate of not more than 1%. This suggests that the displacement and load of steel beams can be measured with strain gauges and further, it will enable more cost-effective sensor designing without displacement meter or load cell. The Structural Health Monitoring System program implemented in Lab VIEW gave graded warnings whenever the measured data exceeds the specified range (strength limit state, serviceability limit state, yield strain), and both the serviceability limit state and strength limit state could be simultaneously monitored with strain gauge alone.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.04a
• /
• pp.375-382
• /
• 2000

This paper briefly summarizes the basic concepts and main characteristics of seismic design of New Zealand Standards(NZS) with regard to reinforced concrete(RC) structures. NZS used the concept of the capacity design and the limit state design to satisfy the requirements of serviceability and safety. Plastic mechanisms and details with respect to the limit state of safety are briefly presented in this paper. The understanding of this advanced seismic design concept will enable us to implement the basic theory of capacity design and contribute to the development of Korean seismic code in new generation,

• Nuclear Engineering and Technology
• /
• v.29 no.6
• /
• pp.444-450
• /
• 1997

The current ASME code for reinforced concrete containment structures are not based on probability concepts. The stochastic nature of natural hazard or accidental loads and the variations of material properties require a probabilistic approach for a rational assessment of structural safety and performance. The paper develops design load factors for the serviceability limit state of reinforced concrete containment structures. The target limit state probability is determined and the load factors are calculated by the numerical analysis. Design load factors are proposed and carried out the reliability assessments.

• Journal of the Korean Society of Safety
• /
• v.29 no.5
• /
• pp.97-103
• /
• 2014

To ensure durability and light weight of bridges, high-strength concrete is required for long-span deck slabs. Such a technology eventually extends the life of bridges and improves the economic efficiency. The results of this study suggests a formula for calculating the minimum thickness of long-span deck slabs built with high strength concrete. The minimum thickness is proposed based on the limit states indicated in the CEB-FIP Model Code and the Korean Highway Bridge Design Code(limit state design). The design compressive strength of concrete used for the study is 80MPa. Moreover, the required thickness for satisfying the flexural capacity and limiting deflection is estimated considering the limit state load combination. The formula for minimum thickness of deck slabs is proposed considering the ultimate limit state(ULS) and the serviceability limit state(SLS) of bridges, and by comparing the Korean Highway Bridge Design Code and similar previous studies. According to the research finding, the minimum thickness of long-span deck slab is more influenced by deflection limit than flexural capacity.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.2
• /
• pp.21-29
• /
• 1993

In this paper, a probability-based reliability analysis was proposed based on a finite element method-based random vibration analysis and serviceability limit state of structures. The limit state model defined for the study is a serviceability limit state in terms of the more realistic crack failure that might cause the emission of radioactive materials. The SAP V-2 is used for a three-dimensional finite element analysis of concrete containment structure, and the reliability analysis is carried out by modifying HRAS reliability analysis program for this study. In this study, the load factors for the design of reinforced concrete cointainment structures in Korea are proposed by considering appropriate load combination criteria for design, and the results are compared with the present ASME code. The proposed load factors were proved to be in accordance with a set of code performance objective and showed consistency in the limit state probability.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.05a
• /
• pp.447-450
• /
• 2005

A prefabricated composite hollow slab with perforated I-beams was suggested for the replacement of deteriorated concrete decks or the construction of new composite bridges with long-span slabs. Composite slabs with embedded I-beams have considerably higher stiffness and strength. For the application of prefabricated composite slabs to bridges, joints between slabs should satisfy the requirements of the ultimate limit state and the serviceability limit state. In this paper, three types of the detail for loop joints were selected and their structural performance in terms of strength and crack control was investigated through static tests on continuous composite slabs. A main parameter was the detail of the joint, such as an ordinary loop joint and loop joint with additional reinforcements. Even though there was no connection of the steel beams at the joints, the loop joints showed good performance in terms of strength. In terms of crack control, the loop joint with additional reinforcements showed better performance. In ultimate limit state, the continuous composite slabs showed good moment redistribution and ductility.

• Structural Engineering and Mechanics
• /
• v.20 no.6
• /
• pp.609-630
• /
• 2005

A reliability analysis method is proposed in this paper through a combination of the advantages of the response surface method (RSM), finite element method (FEM), first order reliability method (FORM) and the importance sampling updating method. The accuracy and efficiency of the method is demonstrated through several numerical examples. Then the method is used to estimate the serviceability reliability of cable-stayed bridges. Effects of geometric nonlinearity, randomness in loading, material, and geometry are considered. The example cable-stayed bridge is the Second Nanjing Bridge with a main span length of 628 m built in China. The results show that the cable sag that is part of the geometric nonlinearities of cable-stayed bridges has a major effect on the reliability of cable-stayed bridge. Finally, the most influential random variables on the reliability of cable-stayed bridges are identified by using a sensitivity analysis.

• Steel and Composite Structures
• /
• v.29 no.1
• /
• pp.91-106
• /
• 2018

This paper investigates the deflection of the steel-concrete composite truss beam (SCCTB) at the serviceability limit state. A precise solution for the distributed uplift force of the SCCTB, considering five different loading types, is first derived based on the differential and equilibrium equations. Furthermore, its approximate solution is proposed for practical applications. Subsequently, the shear slip effect corresponding to the shear stiffness of the stub connectors, uplift effect corresponding to the axial stiffness of the stub connectors and shear effect corresponding to the brace deformation of the steel truss are considered in the derivation of deflection. Formulae for estimating the SCCTB deflection are proposed. Moreover, based on the proposed formulae, a practical design method is developed to provide an effective and convenient tool for designers to estimate the SCCTB deflection. Flexure tests are carried out on three SCCTBs. It is observed that the SCCTB stiffness and ultimate load increase with an increase in the shear interaction factor. Finally, the reliability of the practical design method is accurately verified based on the available experimental results.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.6 s.67
• /
• pp.639-648
• /
• 2003

The objective of this study is to evaluate in-plane and out-of-plane moment transmission capacity of H-shaped beams about design load by stud connector. Four specimens were tested under monotonic moment loading condition in each case to evaluate those. The parameter of tests is the size of the H-shaped beams. The results show that moment transmission capacity of H-shape beams in the serviceability limit state by stud connectors is excellent observing to the design code of steel structures of Architectural Institute of Korea.