• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.1
• /
• pp.29-35
• /
• 2019

The unit modular system is a type of prefabricated construction method that completes the building by uniting the modular units on site by transporting the unit module structure manufactured in the factory to the site. Since the unit module structure is not only the frame but also the finished form including the inner and outer materials, it is most likely to be brought into the field. Therefore, not only the damage of the inner and outer materials but also deformation of frame structure due to the vibration generated during the transportation of the vehicle, And it is necessary to take appropriate methods when transporting the module structure. However, there are no methods to prevent modular structure damage due to vehicle vibration in domestic and foreign modular transportation guidelines or standards. In this study, we investigate the vibrations during the vehicle transportation of the module structure through the road driving test, identify the vibration frequency characteristics of the vehicle through FFT analysis, and propose a vibration reduction methods for module transportation.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.3
• /
• pp.489-501
• /
• 2017

The collapse accidents during a open ground excavation in urban areas not only lead to human injuries and material damages in the construction site, but also lead to road sinks and damages to the adjacent facilities due to settlement of ground around the construction site. Therefore, during a open ground excavation in the urban areas, it is necessary to thoroughly prepare for prevention of collapse accidents, and consider whole construction stage such as planning, design and construction. In this study, the priorities to be managed mainly were obtained in order to prevent collapse accidents during a open ground excavation. After analyzing results from past accidents cases for open ground excavations, priorities were evaluated regarding collapse-inducing elements using the Delphi technique which is a decision-making method by consensus among experts. As a result, insufficient groundwater treatment, bad geotechnical investigation and instability on construction, etc. were obtained as priorities for prevention of collapse accidents.

• Journal of Construction Engineering and Project Management
• /
• v.3 no.4
• /
• pp.20-25
• /
• 2013

Variation in construction means modification of design, changes in quality, quantity of work including the alteration of standard of materials or goods to be used in the work and the removal from site any kind of material not in accordance in the contract. In Ghana, Variation order has become major issue in the construction industry. This had resulted in cost overruns, delay and in some contracts dispute, between parties. The aim of this paper was to identify the root causes of variation; effects of variations on projects in Ghana and the means of reducing the impact of variation order. The method of the study involved literature review, primary data collection, interview and closed - ended- questionnaires. Mean Scores Method was used to rank the identified factors causing variation. Analysis Of Variance Test was use to test for the significant difference between means among the professional groups. The study revealed that most causes of variation were change of design by client and inadequate working details. Establishment of oversight project management committee and flow of information were identified as means of controlling variations during project administration.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.10a
• /
• pp.411-418
• /
• 2002

In domestic road construction sites, the compaction control based on strength are widely performed through the direct method with high accuracy, such as Plate Loading Test or Field CBR test. It is impossible to manage all construction sites using the direct method because the direct method requires heavy reaction loads and long measurement time. Therefore, it is necessary to apply the indirect method that could control the relative density of construction sites on the whole. Indirect methods, such as Cone Penetration Test and Fall Cone Test, require extra time for data analyzing and fixed area for test device. In this paper, the field applicability of Soil Impact Hammer (SIH) was investigated comparing with the results of field measurement tests and laboratory compaction tests. SIH developed by Japan Construction Administration and Asanuma Ltd., is a kind of indirect methods for compaction checking. According to the results of SIH performed in domestic road construction site, the subgrade reaction modulus obtained from SIH are similar to that from Plate loading tests in the range of 10 to 40. In comparison with laboratory compaction test, similar compaction line are shown in the dry side of optimum moisture contents.

• Korean Journal of Construction Engineering and Management
• /
• v.12 no.6
• /
• pp.42-53
• /
• 2011

This study is to present a method of compiling consistently accurate construction cost estimates in minimum of time. There are two kind of applications for estimating system based on quantity-per-unit and the daily work-crew. The former system is still applied 45% as a estimating method to construction job site by the second half of 2010. However, it is necessary for quantity-per-unit to complement the defect of standard integrating specification and improve the integrating method to the various construction conditions. The later system is intended to represent a standard or basic core which can be adopted in many type of construction estimating used across the wide variety of construction in advanced countries. In this study daily work-crew based on productivity is applied to the representative B.O.Q Item in road project. These results are compared to productivity of Japan and U.S.A estimated under the similar circumstances.

• Journal of architectural history
• /
• v.19 no.6
• /
• pp.155-171
• /
• 2010

King Seong carried out the large-scale construction transferring the capital from Wungjin (Gongju) to Sabi (Buyeo) in 538. But because most of the Buyeo area was the low swamp in the time, it needed above all to form a site before transferring the capital. Until recently, in addition to the scientific excavation, the relief excavations for the construction of new building or the formation of road were conducted on many sites in the Buyeo area. As a result, many remains which were formed on the low swamp including the temple site of Neungsan-ri, Dongna Castle, the remains of Ssangbuk-ri (280-5 Bukpo, Hyeonnaedeul) and the remains of Gua-ri were identified. Also in these remains, the various engineering construction methods irrespective of the nature of remains were used for the purpose of the soft ground reinforcement as follows: mattress method of construction, pile designation, stone alignment, filing of decomposed granite soil, culverts and storage tanks. Especially, the mattress method of construction and the pile designation are thought to be the traditional engineering construction method at least in that they are appeared since the Three Han Sates era. And these soft ground construction methods had an effect on the construction of reservoir in Japan at the time. In the future, the construction method for soft ground reinforcement shall be concerned and studied further in the architecture and the civil engineering as well as the archeology.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.23 no.6
• /
• pp.187-200
• /
• 2020

Despite the eco-friendly route plan, road slopes were collapsed due to road construction, resulting in human and property damage. To solve this problem, the Ministry of Land, Transport and Maritime Affairs established guidelines in 2009 to conduct a test-bed for slope recording considering the conditions of the site and the ecological environment, and divided them into recording quality and economic evaluation. The following results were obtained by analyzing 183 construction methods of cut-soil sections at 60 sites from 2012 to 2018 for road slope afforestation research. Straw net+seedspray, vegetation media spray method 1T, 3T were used the most, and vegetation media spray method 3T(patent) was excellent in quality, and straw net+seedspray was excellent in economics. As a result of analyzing the market unit price and the construction unit price, vegetation media spray method submitted the construction unit price at up to 60% lower than the market unit price. As a result of the analysis of the key factors of the greening method evaluation, the economic assessment had the greatest influence on all evaluation items. Problems in the evaluation method of revegetation were first identified as problems in the allocation of points and secondly as problems in the evaluation criteria. As for the improvement of the economic assessment criteria, the method was proposed to evaluate the same method based on market unit price when the same method was constructed, and not to conduct an economic assessment if there was a difference in market unit price between methods, or to add weight to the scores. Based on the monitoring data of 60 road slopes, this study drew up problems and improvement measures. However, with regard to scoring, research on appropriate scoring is needed by examining the current status.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.7
• /
• pp.71-80
• /
• 2010

Korea is considered to be a seasonal frozen soil area that thaws in the spring, and freezes in winter. In the current design codes for anti-freezing layer, the thickness of anti-freezing layer is calculated by the depth frozen due to the temperature condition. Therefore, there is a tendency of over-design and applying uniform thickness without the consideration of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential to study the structural appropriateness of pavement layer and bearing capacity besides the seasonal and mechanical properties of pavement materials to take an appropriate and reasonable design of the road structure. In this paper, the evaluation of frost susceptibility on subgrade, ant-freezing layer, subbase was conducted by means of the mechanical characteristics and model experiment. The temperature, heaving amount, unfrozen water contents and freezing depth of soil samples, the subgrade, anti-freezing layer, subbase soils of road construction site were measured to determine the frost susceptibility.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.935-940
• /
• 2008

To maintain the primary stage of design, it is not too much to say that drainage systems should has been to maintain the most factor in earthwork structures. The durability of earthwork structures has about over 90 years as like concrete structures and has easily used to construction materials. Even if is a good earthwork materials, it hasn't lose design life at inadequate drainage system. In case of railway was frequently performed a maintenance works after construction 5 years because embankment site hasn't installed a concrete duck. In this study, the drainage standard of railway reviews the technological levels of drainage system by comparing the code for design of railway and road.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.12
• /
• pp.145-151
• /
• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.