• Geomechanics and Engineering
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• v.32 no.5
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• pp.503-512
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• 2023

In tunneling projects, a significant part of the costs is spent on segment production. By more economically producing, the cost of tunnel construction can be greatly reduced, especially in long and large-diameter tunnels. In the present study, the effect of using the Carousel method in the improvement of the production system performance compared to the conventional Static system has been studied. To carry out the research, a quantitative comparison of cost and production time was carried out for two production methods using the available documentation. The opinions of experts have been obtained using questionnaires and qualitative comparison of cost, time and production quality was done by implementation of statistical analysis. The SPSS software and the univariate t-test were used to analyze the questionnaires. According to the results of statistical analysis with SPSS, the use of the Carousel method will reduce production time and costs along with increasing manufacturing quality. According to the documentation analysis, the Carousel method reduces the cost of production by almost 30% and leads to a reduction of the production time to approximately 40% of the Static moulds system. The Carousel method has a higher production rate, efficiency, and better performance. Research into quantifying the benefits of Carousel method in the production system performance is very limited. This comparison is based on real information from the under construction Tabriz Metro project. This article can be very helpful in choosing the best production method.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.467-470
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• 2006

The earth volume which is the basis of all the construction has gone through great development so far with the use of construction machine; however, systematic studies on the related area is in need since the appropriate compound engineering method of earth volume equipments which is a key factor for shortening the project duration and cost reduction is not systematically established and it is dependent on experience. Reasonable mechanical earth volume should take into consideration of performance and characteristics of the equipment, the kind of project, scale and conditions in advance. Also, the optimum compound engineering should be planned by selecting several available scales of equipment. In this study, the earth volume estimate model is established for optimum compound engineering of earth volume equipment for mechanized earth volume equipment loading and moving stage among many stages of earth volume task using system dynamics technique. The optimum compound engineering model of the earth volume equipment produced as a result of this is expected to make reasonable decisions in the shortest time in selecting earth volume facility.

• Journal of the Korea Institute of Building Construction
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• v.12 no.2
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• pp.152-160
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• 2012

The development of building must be accompanied with construction technology and performance of materials. In particular, wet processes have a high level of dependence on manpower and a low level of diversification of materials used. This study aimed to determine the applicability of various materials for wet process, mechanized construction and eco-friendly building materials through a comparison with dry premixed mortar. As a result, it was found that resin plaster and gypsum plaster's strength is lower than that of dry cement mortar, but their mechanization application, construction simplification, smoothness and bond strength are higher than that of dry cement mortar. And estimate that is valid as workability, bonding strength, eco-friendly building material in occasion of gypsum plaster.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.421-435
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• 2017

Recently, due to the saturation of ground structures and the overpopulation of pipeline facilities requires to development of underground structures as an alternative to ground structures. Thus, mechanized tunnel construction of the shield TBM method has been increasing in order to prevent vibration and noise problems in construction of the NATM tunnel for the urban infrastructure construction. Tunnel construction plan for the tunnel line should be formed in a sharp curve to avoid building foundation and underground structures and it is inevitable to develop a shield TBM technology that suits the sharp curve tunnel construction. Therefore, this study is about the structural stability technology of the articulation jack, shield jack and skin plate for the shield TBM thrust in case of the mechanized tunnel construction that is a straight and sharp curve line. The construction case study and shield TBM operation principle are examined and analyzed by the theoretical approach. The torque of the cutter head, the thrust of the articulation jack and the shield jack, the amount of over cutting for curve is important respectively in shield TBM construction of straight and sharp curve line. In addition, it is very important to secure the stability of the skin plate structure to ensure the safety of the inside worker. This study examines the general structure and construction of the equipment, experimental simulation was carried out through numerical analysis to examine the main factors and structural stability of the skin plate structure. The structural stability of the skin plate was evaluated and optimizes the shape by comparing the loads of the articulation jack by selecting the virtual soil to be applied in a straight and sharp curve line construction. Since the present structure and operation method of the shield TBM type in domestic constructions are very similar, this study will help to develop the localized shield TBM technology for the new equipment and the vulnerability and stability review.

• Korean Journal of Construction Engineering and Management
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• v.19 no.3
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• pp.3-10
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• 2018

In recent years, mechanized construction has become commonplace due to increases in the scale and complexity of construction, and construction machinery is a major factor in successful construction. However, even though the proportion of construction machinery is increasing, analysis of the work capacity of construction machinery is inadequate. In addition, since the standards for all construction machines are currently not defined in quantity-per-unit, the construction period is arbitrarily applied according to the operator at the time of the construction plan. As a result, the construction period of the actual construction is insufficient, and rushed work or construction delays occur. Therefore, in this study, in order to calculate the construction period of the piling work of the pile driver used in the PRD method more accurately than the existing method, the formula for calculating the time required for the piling work of the pile driver was established by collecting piling time data from the daily task reports through the field survey. If the precise construction period of piling work is estimated based on the results of this study, it will be possible to prevent the rushed work and construction delays that occur due to the short construction period.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.153-166
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• 2017

Recently, the construction industry has been pursuing economical construction by introducing improved construction equipment and methods. However, in many cases, the equipment operation according to the intuition of the field manager and in the manner of traditional methods impedes the increase in effectiveness in terms of productivity and economy. The performance of new construction equipment has rapidly improved; however, the maximum effect of mechanized construction cannot be obtained unless the effective management and operation methods are implemented. According to the expert survey, it has been discovered that the problems of conventional construction equipment operation methods can be classified into several categories: allocation of construction equipment that is not suitable for the construction work, the combination of equipment that does not take into consideration real-time field situations, the decline in the skill of the construction equipment drivers, and lack of real-time access to necessary information. This paper proposes a construction equipment management system to solve these problems. The construction equipment management system can provide a method to maximize the work rate of the construction equipment fleet by developing an equipment allocation plan based on field conditions, whenever necessary, and transferring this information to the construction equipment drivers in real time. Ultimately, it is believed that the application of the construction equipment operation system in the field will make it possible to reduce carbon emissions by improving productivity and reducing fuel consumption.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.29-40
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• 2019

Mechanized constructions have been frequently increased in soft ground below sea bed or river bed, for urban tunnel construction, and for underpinning the lower part of major structures in order to construct a safer tunnel considering various risk factors during the tunnel construction. However, it is difficult to estimate the subsidence behavior of the ground surface due to excavation and needs to be easily predicted. Thus, in this study, when a twin tunnel is constructed in the soft ground, it is proposed a simpler equation relating to the settlement behavior and a corrected formula applicable to soft ground and large diameter shield tunnels based on the previously proposed theory by Peck (1969). For this purpose, it was analyzed to long-term measurement values such as the amount of maximum settlement, the subsidence range by ground conditions, and interference volume loss due to the parallel construction, etc. As a result, a equation was suggested to predict the amount of maximum settlement in the soft sediment clay ground where is located at the upper part of the excavation site. It is turned out that the proposed equation is more suitable for measurement data in Korea than Peck (1969)'s.

• Geomechanics and Engineering
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• v.37 no.3
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• pp.223-241
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• 2024

Evaluating the performance of Tunnel Boring Machines (TBMs) stands as a pivotal juncture in the domain of hard rock mechanized tunneling, essential for achieving both a dependable construction timeline and utilization rate. In this investigation, three advanced artificial neural networks namely, gated recurrent unit (GRU), back propagation neural network (BPNN), and simple recurrent neural network (SRNN) were crafted to prognosticate TBM-rate of penetration (ROP). Drawing from a dataset comprising 1125 data points amassed during the construction of the Alborze Service Tunnel, the study commenced. Initially, five geomechanical parameters were scrutinized for their impact on TBM-ROP efficiency. Subsequent statistical analyses narrowed down the effective parameters to three, including uniaxial compressive strength (UCS), peak slope index (PSI), and Brazilian tensile strength (BTS). Among the methodologies employed, GRU emerged as the most robust model, demonstrating exceptional predictive prowess for TBM-ROP with staggering accuracy metrics on the testing subset (R² = 0.87, NRMSE = 6.76E-04, MAD = 2.85E-05). The proposed models present viable solutions for analogous ground and TBM tunneling scenarios, particularly beneficial in routes predominantly composed of volcanic and sedimentary rock formations. Leveraging forecasted parameters holds the promise of enhancing both machine efficiency and construction safety within TBM tunneling endeavors.

• Magazine of the Korean Society of Agricultural Engineers
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• v.21 no.2
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• pp.21-27
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• 1979

Canal construction is not the only area in which mechanization has advanced with great strides. All phases of the construction industry, including earthmoving, land clearing and levelling, road construction, and drainage and water control projects, have benefited from today's technological advancements. Lasers, an excellant example of advanced technology, have been refined for use as guidance systems for construction machinery, increasing accuracy and the speed of operation. The use of explosives by contractors is becoming more commonplace. One of the most valuable modern tools available today is the two-way radio. On today's sophisticated projects a single machine being down can frequently stop the progress of the entire project, delaying hundreds of men and machines from completing their assigned work for the day. The use of two-way radios in all the pickups and cars being used on a project facilitates communication so that emergency repairs can be effected immediately, and costly down time on any project can be reduced to a minimum. Not every construction project is suitable to mechanization. However, on the majority of projects mechanization has a great deal to offer the Korean contractor, and all contractors, in savings of time and money. Each and every project being considered by a contractor, should be closely examined for the most effective and efficient machinery application available. The International Commission on Irrigation and Drainage (ICID) has formed a committee on construction techniques being used in canal construction today. Two publications are now available describing the advances made in recent years. Standards for construction have been established for mechanized systems and this information is being distributed worldwide.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1137-1140
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• 2005

Automatic welding has been used frequently on pipeline projects. The productivity and reliability are most essential features of the automatic welding system. The mechanized GMAW process is the most widely used welding process and the carriage and band system is most effective welding system for pipeline laying. This application-oriented paper introduces new automatic welding equipment for pipeline construction. It is based on cutting-edge design and practical welding physics to minimize downtime. This paper also describes the control system which was designed and implemented for new automatic welding equipment. The system has the self diagnostic function which facilitates maintenance and repairs, and also has the network function via which the welding task data can be transmitted and the welding process data can be monitored. The laser vision sensor was designed for narrow welding groove in order to implement higher accuracy of seam tracking and fully automatic operation.