Impact Variables of Dump Truck Cycle Time for Heavy Excavation Construction Projects

Song, Siyuan,Marks, Eric,Pradhananga, Nipesh Korea Institute of Construction Engineering and Ma 2017 Journal of construction engineering and project ma Vol.7 No.2

The cycle time of construction equipment for earthwork operations has a significant impact on project productivity. Elements that directly impact a haul vehicle's cycle time must be identified in order to accurately quantify the haul cycle time and implement strategies to decrease it. The objective of this research is to scientifically identify and quantify variables that have a significant impact on the cycle time of a dump truck used for earthwork. Real-time location data collected by GPS devices deployed in an active earthwork moving construction site was analyzed using statistical regression. External data including environmental components and haul road conditions were also collected periodically throughout the study duration. Several statistical analyses including a variance analysis and regression analysis were completed on the dump truck location data. Collected data was categorized by stage of the dump truck cycle. Results indicate that a dump truck's enter idle time, exit idle time, moving speed and driver visibility can significantly impact the dump truck cycle time. The contribution of this research is the identification and analysis of statistically significant correlations of variables within the cycle time.

Analysis and Life Prediction of Bearings in Dump Truck’s Final Drive

장기(Q. Zhang),류성기(S.K. Lyu),허철수(Z.Z. Xu),김동욱(D.G. Kim) 한국트라이볼로지학회 2011 한국트라이볼로지학회 학술대회 Vol.2011 No.4

Construction equipment is heavily loaded during normal operation. In dump truck, the drive axle is one important component which its working ability has a great impact for the whole transmission system. And bearing is main part of the drive axle which its accuracy, vibration and reliability is critically affective for drive axle’s capability and life. For the characteristics of bearings in dump truck, the rotation speed and service load is high, and radial runout exists during the operation. All of these factors would cause bearing’s failure beyond its original life. In this paper, the final drive of dump truck is analyzed and modeled. The bearings of input shaft, output shaft and differential axle are investigated under the six load cases. Therefore, the bearings’ life is predicted and the maximum contact stress is obtained and compared.

토공 운반경로 탐색 시스템 개발에 관한 연구

강상혁,박수현,서종원 대한토목학회 2018 대한토목학회논문집 Vol.38 No.6

This study presents a geographic information system based dump truck route exploring system (DRES) which provides constructionmanagers and hauling operators with efficient route information that can improve earthmoving productivity by reducing hauling time. The system is comprised of Network Analyst from Esri as a route exploring engine and a network data model. The network data modelincludes information on weight limit of bridges, height limit of pedestrian overpasses, and one way that impedes dump trucks’ hauling efficiency. A construction manager is expected to input origin and destination point in the user interface, and the system generates an efficient route that avoids bridges with weight limit or pedestrian overpasses with height limit. The system was applied to a real earthmoving project to test its applicability, and it was found that the system functions as intended. 본 연구에서는 건설관리자 및 덤프트럭 운전자에게 효율적인 토사 운반경로 정보를 제공하기 위한 ‘덤프트럭 운반경로 탐색 시스템(DRES)’을 구축하였다. 이 시스템은 Esri사에서 제공하는 ‘네트워크 애널리스트(Network Analyst)’를 분석 엔진으로 탑재하고 있으며, 경로 데이터는 네트워크 데이터 모델을 활용한다. DRES는 사용자가 출발지(현장)와 목적지(사토장 혹은 토취장)를 선정하면 덤프트럭이 효율적으로 운행할 수 있는 경로를 도출해내도록 구현되었다. 이 경로는 덤프트럭의 운행이 금지된, 제한중량이 있는 교량이나 높이제한이 있는 육교 등을 우회하여생성된다. 개발한 DRES를 사례 현장에 적용한 결과 운행 제약 조건들을 회피하는 경로를 도출하여 운전자에게 더욱 효율적인 경로 정보를 제공하는 것으로 나타났다.

노천광산 덤프트럭의 최적 운반경로 분석을 위한 지형경사가 고려된 벡터 네트워크 자료의 생성 방법

박보영(Boyoung Park),최요순(Yosoon Choi),박한수(Han-Su Park) 한국암반공학회 2013 터널과지하공간 Vol.23 No.5

최근까지 노천광산을 대상으로 덤프트럭의 최적 운반경로 분석을 수행한 연구들은 주로 래스터 자료를 사용하였다. 그러나 래스터 자료는 격자 해상도에 따라 운반경로가 zigzag 형태로 심하게 왜곡될 수 있으며, 경로의 위상관계를 고려할 수 없는 한계가 있다. 벡터 네트워크 자료를 사용할 경우에는 이러한 문제점들을 해결할 수 있으나, 지형경사에 따른 덤프트럭의 성능 변화 특성이 최적 운반경로 분석시 반영될 수 있도록 할 필요가 있다. 본 연구에서는 노천광산 덤프트럭의 최적 운반경로 분석을 위해 지형경사에 따른 덤프트럭의 이동속도 변화를 반영할 수 있는 벡터 네트워크 자료의 생성 방법을 제시하였다. 수치지형모델 제작, 운반도로 디지타이징, 지형 경사도 계산, 경사도를 반영한 트럭의 이동속도 및 이동시간 계산 순으로 자료의 생성 작업이 진행된다. 제시한 벡터 네트워크 자료 생성 방법의 적용성과 효과를 알아보기 위하여 인도네시아 파시르 석탄노천광산의 로또 남부 채광장을 대상으로 간단한 사례연구를 수행한 결과, 제시한 방법이 ArcGIS Network Analyst 소프트웨어와 쉽게 호환이 가능하며, 최적 운반경로 분석시 지형경사에 따른 덤프트럭의 이동속도 변화를 효과적으로 반영할 수 있음을 확인할 수 있었다. Previous studies for analyzing optimal haulage routes of dump trucks in open pit mines mostly used raster data. However, the raster data has several problems in performing optimal route analyses: ⑴ the jagged appearance of haulage roads according the cell resolution often causes overestimation of the travel cost; ⑵ it difficult to trace the topological relationships among haulage roads. These problems can be eliminated by using vector network data, however a new method is required to reflect the performance characteristics of a dump truck according to terrain gradient changes. This study presents a new method to create vector network data with the consideration of terrain gradient for analyzing optimal haulage routes of dump trucks in open pit mines. It consists of four procedures: ⒜ creating digital elevation models, ⒝ digitizing haulage road networks, ⒞ calculating the terrain gradient of haulage roads, and ⒟ calculating the average speed and travel time of a dump truck along haulage roads. A simple case study at the Roto South pit in the Pasir open pit coal mine, Indonesia is also presented to provide proof that the proposed method is easily compatible to ArcGIS Network Analyst software and is effective in finding optimal haulage routes of dump trucks with considering terrain gradient in open pit mines.

쓰레기 매립장 주변 농촌 주민들의 삶의 질 연구

이명경,최준열,김인경,조영아,김영신,정혜진,김리나,이영규,조영태,Lee, Myung-Kyung,Choi, Jun-Yeol,Kim, In-Kyoung,Cho, Yeong-Ah,Kim, Young-Shin,Jung, Hye-Jin,Kim, Li-Na,Lee, Young-Kyu,Cho, Young-Tae 대한예방의학회 2006 예방의학회지 Vol.39 No.4

Objectives: This study aims to examine if a garbage dumping site has real and negative influence on the quality of life (QOL) for the nearby residents. The net effects of the residential distance from the garbage dumping site and from the garbage truck route were investigated for five domains of the QOL. Methods: Two hundred fifty seven Shin-dong Myeon residents, Chun-cheon Si, participated in a self-administrated survey. The Shin-dong Myeon garbage dumping site began operating in 1996. ANCOV A with generalized linear models and multiple regression analysis were performed. Results: Descriptive analyses show that a residence nearby a garbage dumping site is negatively associated with the physical and environmental domains of the QOL. The residential distance from the garbage truck route does not exert any significant effect on various domains of QOL, except for the environmental domain. On the multivariate analysis, the residents living near the garbage dumping site tended to have a significantly negative QOL in the physical and environmental domains. However, the distance from the garbage truck route did not show a significant nor substantial effect on the QOL. The demographic and socioeconomic control variables are associated with a number of the QOL domains, and their patterns are consistent with the general expectations. Conclusions: The results indicated that a garbage dumping site is considered to be an environmental hazard among the nearby residents according to the lower scores on the physical and environmental domains of the QOL. The findings from this study provide comprehensive understanding on the residents' QOL, and they may help politicians and policy makers make decisions for appropriate interventions.

Research and implementation of new-type supercapacitor and battery hybrid energy storage system

Liu, Jian,Wang, Yang,Wu, Yangjie,Li, Yang,Wang, Xiangsheng The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

When a dump truck brakes, it is difficult to effectively absorb the braking energy due to the transient mutation of braking energy. At the same time, braking energy production is too high to store easily. Focusing on these problems, this paper proposes a new type of two-stage series supercapacitor and battery (SP&B) hybrid energy storage system (ESS). Using the characteristics of supercapacitors, which can charge and discharge quickly with large currents, the system combines the supercapacitors with a battery with a high energy storage capacity. This allows sudden large currents to be absorbed and released rapidly, while large amounts of energy can be stored. This system can also reduce the charge and discharge times of the SP&B to meet the working requirements of dump truck braking while improving the service life of the system. After completion of the research and implementation of the proposed SP&B hybrid ESS, a laboratory dynamic model was set up as an experimental platform and vehicle operation experiments were performed. The obtained results show that the energy recovery efficiency of the hybrid ESS can reach 53.5%, which can realize both security and stability for dump truck braking energy recovery and utilization (BER&U) systems.

이산요소법을 이용한 벌크 재료 시뮬레이션에 의한 덤프 트럭 데크 하중산출에 대한 연구

유승훈,우호길 한국전산구조공학회 2020 한국전산구조공학회논문집 Vol.33 No.3

To reduce fuel consumption by reducing the weight of the deck of a dump truck and to design an eco-friendly deck, accurate structural analysis is required. To date, the load on the deck has been calculated based on the hydrostatic pressure or by applying the earth pressure theory. However, these methods cannot be used to determine the non-uniformity of the load on the deck. Load distribution varies depending on the size distribution and interaction of aggregate particles. Compared with the finite element method, the discrete element method can simulate the behavior of aggregate particles more effectively. In this study, major properties were obtained by measuring bulk density and repose. The deck of a 15 ton dump truck was simulated using the obtained properties and bumping, breaking, and turning load conditions were applied. EDEM, which is a discrete element analysis software, was employed. The stress and strain distribution of the deck were calculated by NASTRAN and compared with the measured values. The study revealed that the results derived from a DEM simulation were more accurate than those based on mathematical assumption. 덤프 트럭 데크의 경량화를 통한 연료 소비를 줄이고 에코 친화적인 설계를 위해서는 정확한 구조 분석이 필요하다. 지금까지 데크의 하중은 정수압 또는 토압 이론을 기반으로 계산되었다. 이 방법으로 데크의 하중 불균일을 계산할 수 없다. 하중 분포는 골재 입자의 크기 분포 및 상호 작용에 따라 달라진다. 이산요소법은 유한요소법보다 효과적으로 골재의 거동을 시뮬레이션할 수 있다. 본 논문에서는 벌크 밀도와 안식각을 측정하여 주요 특성을 얻었다. 15톤 덤프 트럭 데크는 범핑, 브레이킹 및 회전 시의 운동 조건을 적용하여 얻은 하중을 사용했다. 시뮬레이션은 이산요소해석 소프트웨어인 EDEM을 사용했다. 데크의 응력 및 변형 분포는 NASTRAN에 의해 계산되었다. 측정된 값과 비교하였고, 이를 통해 DEM 시뮬레이션의 결과는 수학적 가정에 의한 결과보다 정확함을 확인하였다.

Interaction analysis for vision-based activity identification of earthmoving excavators and dump trucks

Kim, Jinwoo,Chi, Seokho,Seo, Jongwon Elsevier 2018 AUTOMATION IN CONSTRUCTION - Vol.87 No.-

<P><B>Abstract</B></P> <P>Activity identification is an essential step to measure and monitor the performance of earthmoving operations. Many vision-based methods that automatically capture and explain activity information from image data have been developed with economic advantages and analysis efficiency. However, the previous methods failed to consider the interactive operations among equipment, and thus limited the applicability to the operation time estimation for productivity analysis. To address the drawback, this research developed a vision-based activity identification framework that incorporates interactive aspects of earthmoving equipment's operation. This framework included four main processes: equipment tracking, action recognition of individual equipment, interaction analysis, and post-processing. The interactions between excavators and dump trucks were examined due to its significant impacts on earthmoving operations. TLD (Tracking-Learning-Detection) was adapted to track the heavy equipment. Spatio-temporal reasoning and image differencing techniques were then implemented to categorize individual actions. Third, interactions were interpreted based on a knowledge-based system that evaluates equipment actions and proximity between operating equipment. Lastly, outliers or noisy results were filtered out considering work continuity. To validate the proposed framework, two experiments were performed: one with the interaction analysis and the other without the analysis. 11,513 image frames from actual earthmoving sites in total were tested. The consequent average precision of activity analysis was enhanced from 75.68% to 91.27% after the interaction analysis was applied. In conclusion, this research contributes to identifying critical elements that explain interactive operations, characterize the vision-based activity identification framework, and improve the applicability of the vision-based method for the automated equipment operations analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A vision-based method classifying types of equipment operations </LI> <LI> Activity identification of excavators and dump trucks from two-dimensional images </LI> <LI> A framework presents equipment tracking, action recognition of individual equipment, interaction analysis, and post-processing. </LI> <LI> Performance improvement through interaction analysis of heavy equipment </LI> </UL> </P>

특수형태근로종사자의 집단적 이익대변 구조

김영문 전북대학교 부설법학연구소 2011 法學硏究 Vol.32 No.-

Nach der ständigen Rechtsprechung des Koreanischen Obersten Gerichtshofs sind arbeitnehmerähnliche Personen, insbesondere self-employed Fahrer(cargo truck owner-drivers and dump truck owner-drivers) keine Arbeitnehmer. Daher dürfen sie nach dem Gesetz zur Gewerkschaft und Beilegung(GGB) keine Koalition bilden. Aber in der Tat haben sie Gewerkschaften gebildet. Diese Gewerkschaften sind Mitglieder der Spitzenorganisation der Gewerkschaften. Das Arbeitsministerium hat dieser Organisation nach § 9 Ⅱ des GGB gefordert, dass die als Arbeitnehmer nicht qualifizierten Fahrer aus den Gewerkschaften ausgetreten werden sollten. In der vorliegenden Arbeit geht es damit um die Struktur einer kollektiven Interessenvertretung für arbeitnehmerähnliche Personen,die wegen ihrer wirtschaftlichen Abhängigkeit soziales Schutzes bedürftig sind. Dump truck owner-drivers und cargo truck owner-drivers haben ein System der kollektiven Interessenvertretung entwickelt. Einerseits haben das betroffene Ministerium, die Vereinigung der Fahrer und die Vereinigung der Arbeitskräfte der Fahrer Nutzenden aufgrund des 'corporatism' eine Komitee zur Zusammenarbeit zu gemeinsamen Interessen, etwa der Harmonisierung zwischen dem Angebot und der Nachfrage der Fahrzeugen. Andererseits haben die Vereinigung der Fahrer und die Vereinigung der Nutzenden ein Formular zum einheitlichen Vertrag zum Kern der Arbeitsbedingungen, insbesondere zum Tarif für den Beförderungspreis, der als eine Mindestarbeitsbedingung eine Rolle spielt. Auf der Betriebsebene können die Vereinigung und jeder Nutzer über dieses Tarifniveau hinaus besseren Beförderungspreis verhandeln und abschliessen. Diese Struktur bedeutet nicht, dass man alle Arbeitskräfte 'arbeitnehmerisieren' sollte und totale arbeitsrechtliche Schutzregelungen auf diese 'arbeitnehmerisierten' Personen anwenden sollte, sondern dass man das Arbeitsrecht externalisieren sollte, so dass man nur einen Teil des Arbeitsrechts auf den Kern der Arbeitsbedingungen der arbeitnehmerähnlichen Personen, etwa den Beförderungspreis, anwenden will. Dieses Modell kann man auch auf andere organisierte arbeitnehmerähnliche Personen übertragen. 대법원 판례에 따르면 특수형태근로자들의 노조법상 근로자성이 부정된다. 따라서 이들의 노동조합 결성도 문제가 된다. ILO는 특수형태근로종사자들의 단결권보호를 우리 정부에 권고한 바 있다. 특수형태근로종사들도 경제적 종속성으로 인하여 사회적 보호가 필요하므로 집단적 이익대변구조를 만들어 줄 필요가 있다. 덤프트럭 종사자와 화물트럭 지입차주의 경험으로부터 먼저 수급조절과 불법적 다단계, 유류대 보조와 같은 정책적 문제를 해결하기 위해서 정부 주도의 노사정협의체가 필요하고, 단가와 같은 핵심적 근로조건에 대해서는 표준계약서를 만들어개별사업장 단위에서 교섭할 수 있는 구조를 만들어 주어야 한다. 물론 이를 위한전제조건으로는 특수형태근로종사자들이 조직화되어야 한다. 이와 같은 집단적 이익대변구조는 전체 노동력 제공자들을 근로자화하여 노동법을 전면적용하는 것이아니라, 핵심적인 근로조건들에 대해서 노동법의 일부를 적용하는 노동법의 외재화(externalization of labour law)의 한 방편들이다.

Cost 절감형 Deck 개발을 위한 15톤 덤프트럭 적재함의 구조해석에 관한 연구

임경채 한국기계기술학회 2020 한국기계기술학회지 Vol.22 No.5

This study aims to respond to the market of Tata Daewoo commercial vehicles in emerging countries (Southeast Asia) lightweight and cost-saving type for the production of dump trucks with secured price competitiveness requested to develop a square deck, and accordingly. This study is a 15-ton dump modified the reinforcement frame of the side gate to reduce the weight of the new truck model deck. It is designed to maintain the strength of 80% or more of the existing gate by (reducing input material). The system and structure rationalization proceeded.