• Journal of the Korea Institute of Building Construction
• /
• v.20 no.2
• /
• pp.147-153
• /
• 2020

It is important to estimate the optimal construction cost at the early stage of the project. In this regard, conceptual cost estimate is an important factor for estimate optimal construction cost. However, domestic conceptual cost estimate are only used as cost per unit area according to the building type, and it's accuracy is not high. Hence, the purpose of this study is to calculate the approximate quantity and cost for reinforcing bars, concrete, and formwork by presenting a regression formula based on the total floor area of the common work items in the frame work. In order to verify the accuracy and validity of the regression formula presented in this study, a comparative analysis was performed by applying the regression formula and the traditional approximate quantity take-off method to real cases. As a result, the estimated error rate of the traditional method was -102~+55%, and exceeded the estimated conceptual cost estimate accuracy range of -50~+100% suggested by AACE(American Association of Cost Engineering). On the other hand, the error rate of the regression formula method presented in this study was -6.4~+11.62%. This can be used not only for conceptual cost estimate range of accuracy, but also for detailed estimates. However, it is necessary to analyze the factors that affect the unit price as well as quantity in order to calculate the appropriate cost.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1C
• /
• pp.19-29
• /
• 2008

As a part of study to develop LRFD (Load and Resistance Factor Design) codes for foundation structures in Korea, reliability analyses for driven steel pipe piles are performed and the target reliability indices are selected carefully. The 58 data sets of static load tests and soil property tests conducted in the whole domestic area were collected and analyzed to determine the representative bearing capacities of the piles. The static bearing capacity formula and the Meyerhof method using N values are applied to calculate the expected design bearing capacity of the piles. The resistance bias factors were evaluated for the two static design methods by comparing the representative bearing capacities with the design values. Reliability analysis was performed by two types of advanced methods: First Order Reliability Method (FORM), and Monte Carlo Simulation (MCS) method using resistance bias factor statistics. The static bearing capacity formula exhibited relatively small variation, whereas the Meyerhof method showed relatively high inherent conservatism in the resistance bias factors. Reliability indices for safety factors in the range of 3 to 5 were evaluated respectively as 1.50~2.89 and 1.61~2.72 for both of the static bearing capacity formula and the Meyerhof method. The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, based on the reliability level of the current design practice and considering redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.31 no.1
• /
• pp.53-61
• /
• 2018

Ballast track requires constant maintenance work due to progress of track irregularity. Fast Hardening Track(FHT) has been developed to reduce the maintenance effort done by injecting fast hardening mortar in aged ballast to convert slab track. For the application of FHT to a railway bridge, post-installed anchors should be placed at center of the track segment to fix it on bridge. This paper presents track-bridge interaction analysis results with FHT considering stiffness and strength of post-installed anchor, age of FHT concrete and friction between FHT and bridge deck surface. Based on the analysis results, this study suggests when is good to install the anchors and allow normal operation of passing train.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.581-584
• /
• 2003

Recently, construction industry has an interest on the maintenance area of construction facilities to maximize utilization of the each facility. This study suggests an interactive electronic technical manual for bridge facility to improve quality and to ensure safety of the bridge facility. The improvement method of bridge maintenance system consists of the basic information ell the facilities, maintenance manuals and measurement system. And the suggested system is based on the facilities, maintenance manuals and measurement system. And the suggested system is based on IETM (Interactive Electronic Technical Manual), and this study defines and develops a $BF\_IETM (Bridge Facility\_ITEM$ as the bridge maintenance system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.40-47
• /
• 2003

The main purpose of Construction Management(CM) is the improvement of efficiency and effectiveness of the project with construction methodologies systematically and technically. This pilot project Dong Myeong Service Area and Gas Station project among 5 projects designated and supervised by Ministry of Construction and transportation(MOCT), is to reduce cost, to maintain and control schedule, to keep proper quality, Claim and Risk through Partnering, Design Review, Constructability, Value Engineering and Project Management Information System(PMIS) and so on. Major factors of CM Plan are introduction of the phased and classified Construction Management Services from initiation of project to completion and adaptation of CM technologies and guide the implementation methodologies of the CM Pilot Project in CM construction market.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.27 no.4
• /
• pp.274-279
• /
• 2015

Wave data acquired over eleven years near Sokcho Harbor located in the central area of the east coast were analyzed using spectral method and wave-by-wave analysis method and its major wave characteristics were examined. Significant wave heights were found to be high in winter and low in summer, and peak periods were also found to be long in winter and short in summer. The maximum significant wave height observed was 8.95 m caused by the East Sea twister. The distributional pattern of the significant wave heights and peak periods were both fitted better by Kernel distribution function than by Generalized Gamma distribution function and Generalized Extreme Value distribution function. The wave data were compiled to subdivide the wave height into intervals for each month, and the cumulative occurrence rates of wave heights were calculated to be utilized for the design and construction works in nearby construction works.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.629-633
• /
• 2004

The number of claims and disputes among project participants has been steadily increasing last a few years and it creates numerous conflicts and problems in the domestic construction industry. One of the root causes of claims and disputes can be explained by the fact that project objectives of participants are offer different and not aligned. This research is considered as a pre-study of developing a strategy to mitigate conflicts such as claims and disputes in the domestic construction industry by utilizing Alternative Dispute Resolution (ADR) techniques. This research focused on improving standard contrast documents to establish a systematic dispute resolution process which emphasize the ADR method. To do so, several well-recognized contract documents developed by FIDIC, AIA, ECC were throughly investigated and analyzed using a benchmarking process. Result of the research propose needs of improving the domestic construction document's some clauses and the details will be further Investigated through surveys and expert's opinions.

• Magazine of the Korea Concrete Institute
• /
• v.9 no.4
• /
• pp.155-165
• /
• 1997

Since the biggest time-dependent prestress loss of reactor containment structure is due to creep of concrete. the creep is one of important structural factors to be considered for the safety maintenance in the containment structure during design. construction and main enance. This paper is about the creep charactoristies of concrete for the reactor containment structure. In this paper, creep test was performed to show the creep characteristics of reactor containment concrete structure made of the type-V cement. Then, in order to evaluate the applicability of creep prediction equations of recently revised Korean Concrete Standard Specification(KSCE-96) and Japanes Concrete Standard Specification. ACI-209. CEB/FIP-90. and HANSEN, creep test results were compared with prediction results obtained from he equations. From the comparisons, it was shown that the equation of th KSCE-96 predicts creep for younger concrete than 1 year, better than the other equations and that all of the equations predicts creep, for older concrete than 1 year, smaller than test. From regression analysis. a creep prediction equation which effectively predicts creep of concrete due to loading after 1year was proposed.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.27 no.2
• /
• pp.142-147
• /
• 2015

Wave data acquired over seven years near Daejin Harbor located in the north central area of the east coast was analyzed using spectral method and wave-by-wave analysis method and its major wave characteristics were examined. Significant wave heights were found to be high in winter and low in summer, and peak periods were also found to be long in winter and short in summer. The maximum significant wave height observed was 6.59 m and was caused by Typhoon No. 1216, SANBA. The distributional pattern of the significant wave heights and peak periods were both reproduced better by Kernel distribution function than by Generalized Gamma distribution function and Generalized Extreme Value distribution function. Meanwhile, the wave data was subdivided by month and wave height level and the cumulative appearance rate was proposed to aid designing and constructing works in nearby coastal areas.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.7 no.1 s.24
• /
• pp.1-9
• /
• 2007

This study does by purpose that propose shear resisting force equation of reinforced masonry wall that is reinforced by GFRP(glass fiber reinforced polymer) based on result that is noted through cyclic loading of masonry wall and a shaking table experiment of mock that reflect identifying marks of masonry building which is constructed in domestic. It was Rocking mode to dominate failure of masonry wall in the experiment results, and the equations of UBC show the most resemblant value with experiment results. Through this study, propose the shear force equation of GFRP strengthened masonry wall as following. $$V_n=0.02A_n{\sqrt{f'_m}}+0.022b_gh_g(1+2{\alpha})^3{\sqrt{f_g}}(N/mm^2)$$.