• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.42-52
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• 2021

The cost of remodeling parking lots of apartment houses accounts for about 20 percent of the total cost of remodeling. This means that when the remodeling cost of the underground parking lot is known, it becomes possible to estimate the total construction cost. The standard of estimation referenced when calculating the construction cost is difficult to apply to calculating the remodeling cost. Thus, a construction cost estimation model that reflects the characteristics of remodeling construction is necessary. This study developed a basic construction cost estimation model for expansion remodeling of underground parking lots of apartment houses that calculates the approximate cost of construction by reflecting the characteristics and design elements of remodeling. Based on literature review and consultation with experts, 37 activities of underground parking lot remodeling construction were derived. In order to enable calculation of approximate construction cost before the remodeling design drawing is finalized, the quantity calculation formula and unit price for each activity were presented. Based on expert advice, 13 factors that affect the increase in construction cost and weights of each factor were determined. As a result of applying three cases of remodeling complexes to the basic cost estimation model, the accuracy was confirmed to be 93 percent on average.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.355-358
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• 2002

Since the 1960s, though there were brisk supply in apartment housing, there were no preparation in standard for to extend the life(durability) of apartment housing by maintaining the $social{\cdot}physical$ aspect of apartment housing, and in standard maintenance system. So problem such as facilities safety and residence environment has occurred. Like the condition written above, efficient usage of housing resource by the maintenance of apartment housings in a state of great urgency. In service aspect of apartment housing, establishment of accurate long term repair plan and estimate of repair appropriation fund can prevent housing's fast-deterioration. But to the performers of the maintenance, like house managers and the tenants at the subject building has little awareness of necessity in establishment of accurate long term repair plan and accumulation of repair appropriation fund. Unestablishment of long term repair plan arises problem such as approval of repair appropriation fund's unreasonable accumulation. Hence, for the utmost performance of apartment housing and to extend the economic life of a building, the method of establishment of long term repair plan and estimate of repair appropriation fund on reliable basis is to be proposed.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.597-608
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• 2011

It has been often noted as a problem that as there are no objective and clear criteria for the repair cost estimate of persistent defects, when a claim arises in relation to an apartment construction, significantly different amounts of compensation may be given for similar defects based on the experience and tendencies of the construction experts asked to make a judgment. For this reason, this research aims to present defect managers with a more reasonable and objective estimation criteria and a system to determine the repair cost of defects based on an analysis of relevant factors. The research findings show that the historical cost system is applied first, and then a standard of estimation is used to estimate the cost for the items that are not included in the historical cost system. The criteria for the repair cost for each defect is as follows: the repair cost for defects arising from a regulation violation is determined by calculating the reconstruction cost of the parts in question after demolishing them; the repair cost for progressive defects is determined based on a contribution ratio proportional to the age of the building; the repair cost for repetitive defects is calculated by considering an alternative to maximize the intended function of the defective parts; and the repair cost for value depreciation defects is determined based on the ratio of the warranty period to the lapsed years. However, repair cost estimation for dual value depreciation defects should be studied in future research.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.5
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• pp.163-170
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• 2006

Recently, piezocone penetration test is frequently used in order to estimate the characteristics of soft ground with standard penetration test, generally used in the past. In this study, the correlation of standard penetration test, piezocone penetration test and driving resistance of vertical drain is analyzed in order to increase the confidence for determination of soft ground depth. As the results of each zone, the relation between standard penetration test and piezocone penetration test shows qc=(1.09~1.63)N at the soft ground, determined by 5/30 N value which is decided for soft ground criteria. And qc=(1.21~1.98)N was shown at the point of compressible layer, evaluated by the preconsolidation pressure. And driving resistance of vertical drain is $65{\sim}70kgf/cm^2$ which is equal to $10kgf/cm^2$ of cone penetration resistance.

• 기술발표회
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• s.2006
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• pp.261-269
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• 2006

Recently, piezocone penetration test is frequently used in order to estimate the characteristics of soft ground with standard penetration test; generally used in the past In this study, standard penetration test, piezocone penetration test, driving resistance of vertical drain were used in order to increase the confidence for determination of soft ground depth. And the compressible layer was determined by the comparison between the preconsolidation pressure and the designed increase pressure. As the results, the relation between standard penetration test and piezocone penetration test shows $q_c$=(1.09~1.63)N at the soft ground, determined by 5/30 N value. And $q_c$(1.21~1.98)N was shown at the point of compressible layer, evaluated by the preconsolidation pressure. And driving resistance of vertical drain is 70 f/$cm^2$ which is equal to 10kgf/$cm^2$ cone penetration resistance.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.303-312
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• 2006

The main objective of this experimental study is to examine the feasibilities of each testing method with various kinds of grip systems for the analysis of tensile strength of GFRP(glass fiber reinforced polymer) reinforcing bars. Three types of grip systems were examined such as resin-sleeved pipe-type grip proposed by CSA(Canadian Standard Association), frictional resistance type metal grip by ASTM(American Standard for Testing and Materials) and wedge-inserted cone-type grip normally used in prestressing tendons. Also, mechanical properties of GFRP rebars with different surface deformations were investigated for each different type of testing grip used in this study. All testing procedures including specimens preparation, set-up of test equipments and measuring devices were made according to the CSA S806-02 recommendations. From the test results, it was found that the highest tensile strengths of GFRP rebars were observed when tested by resin-sleeved grip system regardless of their different surface deformations. But tensile strengths of GFRP rebars by ASTM grip system are only 10% less than those by CSA grip system. On the other hand, CSA grip is not only difficult to prepare but also not disposable. Therefore, ASTM grip system is recommended as a practical alternative to estimate the tensile strength of GFRP rebars.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.82-92
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• 2018

Considering that earlier stage of construction project has a great influence on the possibility of lowering of environmental load, it is important to build and utilize system that can support effective decision making at the initial stage of the project. In this study, we constructed an environmental load estimation model that can be used at the early stage of the project using basic design factors. The model was constructed by using the artificial neural network to estimate environmental load by applying to planning stage (ANN-1), basic design stage (ANN-2). The result of test, shows that average of absolute measuring efficiency and standard deviation of ANN-1 and ANN-2 were 11.19% / 5.30% and 9.59% / 3.09% each. This result indicates that the model using the input variables extended with the project progress has high reliability and it is considered to be effective in decision support at the initial design stage of the project.

• Korean Journal of Construction Engineering and Management
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• v.23 no.3
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• pp.3-12
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• 2022

In general construction project planning ratio of manpower and quantity of outputs produced, such as the construction estimate standard, is used as the criterion for labor productivity. This method is highly effective in construction projects with repetitive work, however, there is a limit to apply in large-scale projects with high complexity. This is because the influence of non-work time caused by various work interruption factors that act complexly on the productivity of the project is greater than the average labor productivity derived from the performance data of the project. Therefore, this study proposes a productivity measurement method that can evaluate the characteristics of construction works and the cause of non-working time. To this end, first, detailed work processes and their non-work factors for each work type are defined, and the Adv-FMR technique is developed for quantitatively measuring them. Next, based on the concept of obtainable productivity, methods for comparative productivity analysis by work type, evaluating non-work factors, and deriving productivity improvement methods are proposed. Finally, a case study is conducted to validate that the analysis results based on Adv-FMR data can support the decision-making of construction managers on productivity management.

• Korean Journal of Construction Engineering and Management
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• v.11 no.5
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• pp.53-64
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• 2010

Remodeling becomes the significant issue in the aspect of the resource recycling, because it does not demolishes the whole buildings, but a part of main structure. However, compared with new construction, remodeling has several problems of adding the repair and rehabilitation works, using the partial demolition method, and having difficulties of making decision due to disagreement between several owner organizations. BIM, which is the total solution for managing and producing information during whole life cycle of the buildings, seems to be the right solution for the way to address these issues. has a possibility for solving the problems. Therefore this paper provided the framework and database for applying the BIM in the remodeling, and proved the applicability of the BIM database in the remodeling project through the case studies.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.155-165
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• 2004

Hydrological model which is proper to watershed characteristics and analysis purpose must be used when we analyze water resources. But, although proper model is used, if objectivity and reasonability of data is low it is difficult to get good results from the model. So it is very important to decide the data which is used in selected model and estimate parameters by using the applied data. In this study, temporal and spatial data was constructed as standard data of test site and stored in HyGIS (Hydrological Geographic Information System) DB. A system which extracts temporal and spatial data required to run hydrological model from HyGIS DB by connecting TOPMODEL with HyGIS was developed. In this system, we can extract temporal and spatial data which is needed to run TOPMODEL from HyGIS DB and estimate model parameters by using genetic algorithm. We found that HyGIS and the system connected with TOPMODEL was effective to make temporal and spatial data used in TOPMODEL and estimate model parameters. From this study, we suggested the possibility that HyGIS could be applied properly to another hydrological model, too.