Ung-Kyun Lee

Improvement of estimating method for construction management service fee by case study

The objective of this paper is to suggest the improvement of estimating system for construction management (CM) service fee through the analysis of the previous literatures and criteria and case study. In order to do this, this paper considered the relevance of existing criteria to estimate the CM service fee, the condition of input ratio of engineering resources in the real cases, and current utilization strategy of nonresident technical engineers. Based on the analysis, the following problems were identified; a) the different estimating system for CM fee and construction supervision fee, b) impractical estimating system for the CM fee, and c) inappropriate allocation of human resources for CM. Consequently, this paper suggested the following 4 items for the improvement of the existing system; (1) modification of the current structure of CM fee calculation, (2) rationalization of current level of the CM fee which is required to be raised approximately 5.4 percent compared to design or supervision fee, (3) securement of elasticity of the input ratio of engineering resources from the inception phase, and (4) development of the utilization strategy of nonresident engineers based on the technical requirement of the jobsite. Thus, it is anticipated that this research would affect the compensation package of CM in order to make the estimation process of CM service fee more efficient and to revitalize CM as business.

Mass concrete curing management based on ubiquitous computing

Abstract: With the spread of networking and computing technologies, ubiquitous computing is a concept attracting increasing attention in industrial development and innovation. In this study, a mass concrete curing management system (CMS) is introduced to investigate the possibility of applying ubiquitous computing to jobsite project execution. The proposed CMS consists of three parts—wireless data acquisition, strength estimation, and an alarm. A case study is performed to validate the CMS in the mat foundation of a high-rise building construction. This system will allow the project engineers or managers to make timely decisions about the cooling operation of the pipe cooling system, which removes hydration heat from the concrete with embedded cooling pipes in the structure, and about the timing of formwork stripping. This suggests that the productivity and efficiency of construction management can be improved by adopting a ubiquitous computing environment in construction.

Performance assessment model for robot-based automated construction systems

An adjusted assessment model based on benefit-cost analysis (BCA) is proposed for evaluating the economic efficiency of automated construction technologies. In contrast to conventional BCA, the model does not compare monetary values, but the differences in benefits and costs between traditional and automated construction methods. To verify the usefulness of the model, it was applied to a real-scale building construction project that used a fully automated building construction system, and the face validity of the model was confirmed. The results indicate that the model can support decision makers in identifying valuable benefit factors and in assessing the cost effectiveness of the system.

Case study of a synchronous hydraulic jack-up system for constructing high-rise residential buildings

In recent years, contractors have frequently needed to apply innovative technologies to fulfil architects’ creative and intricate designs. They have often encountered abnormal construction conditio...

A study on the economic analysis of high-rise residential-commercial building that is made by precast concrete

The increase of hish-rise residential-commercial buildings is required to cut down a term of works and the cost of construction. Reinforced concrete structures and steel framed reinforcement concrete that are commonly used have the difficulty in reducing them. Therefore, the purpose of this study is to propose a new precast concrete complex system and to analyze its economical feasibility. The economic analysis is performed through comparing the cost of a high-rise reinforced building that was already constructed with that of the new proposed precast concrete system, which is limited to structural frame work of typical floors. This study shows that the proposed precast concrete complex system is economical. Further research should be directed at including the influence of a term of works.

Robotic technologies for the automatic assemble of massive beams in high-rise building

In this paper, we introduce a new technique for automatic construction of steel frames in high-rise buildings. Basically, we combine advanced robotic technologies to building construction techniques. Four main topics will be developed such as: 1) Planning and synthesis of automatic construction system (ACS); 2) Development of construction factory(CF) system with climbing oil-pressured robot; 3) Core techniques for automatic assembly for steel frames; and 4) Intelligent resource management system. We expect that this new technique will increase the construction efficiency and will alleviate the manpower shortage problem in the aging society. For the development of the proposed system, two main ideas will be suggested. The first idea is to utilize a transportation system for the robot. One of the main problems of the automatic construction is that the size of the construction factory is very huge while that of the robot is not. To alleviate the problem, we suggest a transportation system which combines a rail with a boom. The second idea is to use a wire suspended positioning system. In the construction, it is a main issue to bring the guiders and beams in a pre-planned position with an accuracy of 2 mm. Nowadays, it is operated by two skilled workers. Through our research, We want to implement it automatically by utilizing the wire suspended positioning system which is controlled by the cable of a tower crane and multiple wires.

An analysis of the utilization of defect deposits for apartment complexes

This study analyzed the actual use of defect deposits for financing long-term expenses (that is, expenses incurred within 4?10 years of building completion) and for financing short-term expenses (that is, expenses incurred within 3 years of building completion). Therefore, 36 cost data on the expenses financed out of defect deposits for apartment complexes were collected from construction companies and analyzed using statistical methods. The findings revealed that 62.6 percent of defect deposits were spent to resolve actual defects, and 37.4 percent were spent resolving resident complaints. Furthermore, these results are valid regardless of the location of the complexes. As such, these results could be of significance when establishing or revising regulations regarding the repair of the long-term defects of apartment complexes.

Improvement on the Non-standardized Name Use of Chinese Granite for Korean Building Constructions

The purpose of this study is to analyze the problem of confusing the names of Chinese granite used in Korean construction work and suggest the improvement plans for them. Interviews of the experts from the stone company, studies on the existing research literature, and analyses of construction work documents of the 23 construction works which used Chinese granite were carried out to analyze the real condition of name confusion of granite stone. In the analytical result of the real condition, name confusion was classified into 4 types and problems derived from it were done into 4 ones. An additional survey was carried out targeting 34 masonry experts to draw the improvement plans based on the analytical results of the real condition of name confusion. The results show that the most fundamental solution is to continue to make efforts to use exact names when main agents related to construction works communicate with each other regarding Chinese granite stone and the process to make out construction contract documents.

Assessment of Requirements for Successful Mobile Project Management Information Systems

The objective of this study is to assess the requirements of tablet PC-based PMIS applications designed for use on construction sites to determine whether these new programs can play a significant role in increasing the efficiency of a project. In this research, the current market conditions of PMIS running on a tablet PC were analyzed. In addition, two industry surveys were conducted. A research team interviewed some industry experts and identified fourteen useful and desirable functions that can be incorporated into tablet PC-based applications and project management tools. Through a questionnaire survey, the most effective functions for the tablet PC-based PMIS were identified. The three top-rated functions among those suggested were Contact Information for Job-Related Personnel; Receive and Respond to Submittals, RFIs, and Notices; and Problem Solving for Design and Engineering Issues. The results of this research are expected to provide helpful information for mobile application developers and members of other interested groups in the construction industry.

Integrated Lifting Model of Planning and Operation for Finishing Works in Tall Building Construction

The objective of this study is to propose an integrated lifting model of planning and operation for finishing works in tall building construction. The model consists of five components: lifting schedule chart, lifting load leveling, lifting equipment planning, lifting TACT and lifting table. The model was designed to provide a more practical lifting planning and operating method for construction managers as well as to cope with unexpected schedule delays. To validate the proposed model, a case study was performed in building a construction project; questionnaires were distributed in order to evaluate its effectiveness compared with the original method. A case study showed the following results. (1) The model is estimated to provide more practical lifting planning alternatives compared with the original method to construction managers. (2) The model can be a valuable management tool in terms of the lifting operation of construction lift. (3) The model can be provide an effective method to cope with unexpected situations through the integration of lifting planning and operation. Therefore, It is expected that the proposed model can be employed as practical means to the planning and operation of construction lift at construction sites.