• Journal of the Korea Concrete Institute
• /
• v.26 no.2
• /
• pp.211-218
• /
• 2014

In the design of reinforced rectangular concrete beam structure, the minimum amount of flexural reinforcement is required to avoid brittle failure. KCI code is based on concept of ultimate strength and usually used as a model code. But bridge design code enacted by Ministry of land, transportation and maritime affairs in 2012 is based on concept of limit state and similar to Euro code EN 1992-2. This means that the minimum reinforcement presented in both design codes has different origination and safety margin. When rectangular concrete beams with minimum reinforcement are designed according to EN and KCI codes, the amount of minimum reinforcement specified in EN code is only 76% of that in KCI code. This makes the design engineers to be confused. In this study, flexural tests were conducted on nine beams with the two different minimum reinforcement specified in KCI and EN design codes. In results, the measured ratios of nominal strength to crack strength from the test were about 25% greater than those evaluated from the equations presented in KCI and EN codes. The EN beams having only 76% of the minimum reinforcement for the KCI beams were fractured by rupture of steel reinforcement but in ductile manner. It is confirmed that the minimum reinforcement concrete beams designed according to both codes have enough safety margin in flexural capacity and moreover in ductility.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.6 no.4
• /
• pp.53-60
• /
• 1986

This study is directed to propose a probability based LRFD design code, which could possibly replace the traditional USD provisions of the current code, based on the AFOSM reliability theory. The uncertainties of resistances and load effects for each R.C. structural elements are evaluated and adopted considering our practice, and a set of rational target reliability indices are selected based on the calibration with the reliability of the current R.C. design code and by considering the desired hierarchy of safety level. Then, a set of common load factors are chosen from the results of load and resistance factors which are computed by AFOSM method using the Rackwitz-Fiessler's efficient practical algorithm which is to transform the non-normal variables into the equivalent normal variables. It may be asserted that the proposed LRFD code for the R.C. building structures may have to be incorporated into the current RC. design codes as a design provision corresponding to the USD provisions of the current R.C. design code.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.5 no.3
• /
• pp.261-266
• /
• 2017

In this study, to determine the shear properties, experiments on the shear behavior of plain concrete with the high volume fly ash cement by double shear test were performed. Test parameters are fly ash content and concrete compressive strength. Experimental results show the tendency that the shear strength similarly increases with an increase in the compressive strength as is generally known. The concrete shear strength formula proposed in the concrete structural design code of KCI shows a similar tendency to the experimental results, and It is expected that the shear strength of the high volume fly ash cement concrete can be applied with the formula given in the concrete structural design code of KCI. When considering the fly ash content ratio, the shear strength of high volume fly ash cement concrete according to fly ash conctent ratio shows as having a far greater correlation than if it is not considered to fly ash content ratio. So, even though existing code can be appliable for non consideration of the fly ash content ratio, we proposed a formula that is much more relevant than that of concrete structural design code of KCI.

• The Korean Society of Law and Medicine
• /
• v.16 no.1
• /
• pp.221-254
• /
• 2015

The amendment of the Korea Civil Code will take place July 1, 2013. One of the most import issues related to adult guardianship system is a part. Though more than 100 new provisions, the revised Civil Code fundamentally reformed the guardianship system to establish a system to meet the diverse and complex needs of those who need a guardian and ensure due process. The new adult guardianship system intended to respect dignity and human right of mentally incapacitated adults, to guaranee their autunomy and to minimize the public interventions for assisting them. The new guardianship system for vulnerable adult has three kinds of legal guardianship system (adult guardianship, limited guardianship and specific guardianship). Mental patients forced the hospitalization of the mental health code and will be treated as an agreement incapable person. In principle an agreement incapable person has capacity of consent. The consent of the mental patients are admitted first. It is advisable to medical care only by the consent of the guardian when the the mental patient do not agree ability. If the mental patient do not agree with the mentally ill, but there should be a supervisory capacity for a guardianship of the couple guardian supervision. In conclusion, it not lost the capacity to consent to inpatient mental illness called. Therefore, we must discuss in detail the scope of the agreement for the mental patients. Mental Health Act amendments are necessary in accordance with the amended Civil Code.

• Journal of Korean Society for Geospatial Information Science
• /
• v.22 no.1
• /
• pp.31-39
• /
• 2014

The trend of information service and its utilization has been gradually evolving due to the technological breakthrough in IT industries and the spread of smart phones. Especially regarding smart phones, a vast array of applications are being developed and employed for the purpose of providing real time information. Recently, numerous studies have been made and applied in regards to the efficient management and the supply of cadastral control point information. This research has developed and applied the NFC Cadastral Control Point, an advanced version of QR code Cadastral Control Point, which is installed and utilized in Dong-gu Ulsan, Korea, and an application that can utilize both the QR code and the NFC. In addition, this research continues on to analyzing the utility of the two methods that the survey use of a General Cadastral Control Point and the NFC Cadastral Control Point. Having implemented both methods, NFC Cadastral Control Point outweighed its counterpart in terms of the damage it gets from the outside influence and availability. Moreover, through developing Cadastral Control Point that could apply both the QR code Cadastral Control Point and NFC Cadastral Control Point, the research saw tremendous improvements compared to the survey method using the previously existing reference point performance. The results conveyed the fact that cadastral information application was time saving, convenient, and efficient in terms of finding information. Henceforth, with government's administration over Cadastral Control Point and with the development of more application for providing information, a nation-wide monitoring of Cadastral Control Point is considered possible and an efficient usage of information service is expected as well.

• Advances in concrete construction
• /
• v.9 no.1
• /
• pp.43-54
• /
• 2020

This paper presents an innovative stress-function variational approach in formulating the interfacial shear and normal stresses in an externally bonded concrete joint using carbon fiber-reinforced plastic (CFRP) plies. The joint is subjected to surface traction loadings applied at both ends of the concrete substrate layer. By introducing two interfacial shear and normal stress functions on the CFRP-concrete interface, based on Euler-Bernoulli beam idea and static stress equations of equilibrium, the entire stress fields of the joint were determined. The complementary strain energy was minimized in order to solve the governing equation of the joint. This yields an ordinary differential equation from which the interfacial normal and shear stresses were proposed explicitly, satisfying all the multiple traction boundary conditions. Lamination theory for composite materials was also employed to obtain the interfacial stresses. The proposed approach was validated by the analytic models in the literature as well as through a comprehensive computational code generated by the authors. Furthermore, a numerical verification was carried out via the finite element software ABAQUS. In the end, a scaling analysis was conducted to analyze the interfacial stress field dependence of the joint upon effective issues using the devised code.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.1
• /
• pp.47-54
• /
• 1993

For the numerical analysis of free oscillation characteristics in a harbor with general boundary and bottom topography, finite element method is applied. The governing Helmholtz equation is transformed into a generalized matrix eigenvalue problem using the standard finite element procedure. A computer code is developed for the numerical evaluation of natural frequencies and free oscillation modes. In the eigensolution process, a shifting strategy is devised for the treatment of numerical singularity. Scaling of coefficient matrix is also found to be effective for the alleviation of numerical ill-conditioning. For the test problems, firstly, analytical and numerical solutions are compared and validity of the code is obtained. Hence the method is successfully applicable for the real-world problems with general geometric boundaries and bottom topography.

• Earthquakes and Structures
• /
• v.9 no.1
• /
• pp.93-109
• /
• 2015

Based on the reconnaissance of buildings in Dujiangyan City during 2008 Wenchuan earthquake, China, structural damage characteristics and the spatial distribution of structural damage are investigated, and the possible reasons for the extraordinary features are discussed with consideration of the influence of urban historical evolution and spatial variation of earthquake motions. Firstly, the urban plan and typical characteristics of structural seismic damage are briefly presented and summarized. Spatial distribution of structural damage is then comparatively analyzed by classifying all surveyed buildings in accordance with different construction age, considering the influence of seismic design code on urban buildings. Finally, the influences of evolution of seismic design code, topographic condition, local site and distance from fault rupture on spatial distribution of structural damage are comprehensively discussed. It is concluded that spatial variation of earthquake motions, resulting from topography, local site effect and fault rupture, are very important factor leading to the extraordinary spatial distribution of building damage except the evolution of seismic design codes. It is necessary that the spatial distribution of earthquake motions should be considered in seismic design of structures located in complicated topography area and near active faults.

• Earthquakes and Structures
• /
• v.9 no.4
• /
• pp.893-910
• /
• 2015

Earthquake safety of existing buildings has gained considerable importance after earthquakes which have occurred in our country especially in the last 30 years. Performance based assessment methods have been widely used for existing reinforced concrete structures. This study aims to investigate the earthquake performances of the building stock located in Van Lake basin in Eastern Anatolia of Turkey. The case study of buildings has been modeled on and the structural performances have been determined by employing the non-linear methods described in the latest Turkish Earthquake Code published in 2007. The Van lake basin is located on the very seismically active in a region. On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey. The earthquake ground motion was recorded as about 0.1g in Bitlis province. Performance evaluations have been performed by taking samples from each district consisting urban building stocks of Bitlis. A total of 16 reinforced concrete buildings have been evaluated. Among them, 53% of those buildings were determined in the Fully Operational performance level; 13% of them in the Life Safety performance and 34% of them could not be evaluated because of the ratio of the effective mass of first mode to the total mass of the buildings was smaller than 0.70. Therefore, incremental equivalent seismic load methods, which are a part of Turkish Earthquake Code -2007, cannot be used.

• Steel and Composite Structures
• /
• v.9 no.5
• /
• pp.457-471
• /
• 2009

This study investigates the role of accidental torsion in seismic reliability assessment. The analyzed structures are regular 6-story and 20-story steel office buildings. The eccentricity in a floor plan was simulated by shifting the mass from the centroid by 5% of the dimension normal to earthquake shaking. The eccentricity along building heights was replicated by Latin hypercube sampling. The fragilities for immediate occupancy and life safety were evaluated using 0.7% and 2.5% inter-story drift limits. Two limit-state probabilities and the corresponding earthquake intensities were compared. The effect of ignoring accidental torsion and the use of code accidental eccentricity were also assessed. The results show that accidental torsion may influence differently the structural reliability and limit-state PGAs. In terms of structural reliability, significant differences in the probability of failure are obtained depending on whether accidental torsion is considered or not. In terms of limit-state PGAs, accidental torsion does not have a significant effect. In detail, ignoring accidental torsion leads to underestimates in low-rise buildings and at small drift limits. On the other hand, the use of code accidental eccentricity gives conservative estimates, especially in high-rise buildings at small drift limits.