Calculation analysis of bulldozer's productivity in gravitational transport on open pits

Scientific paper - Original scientific paper

• Title (croatian): Analiza proračuna učinka dozera pri gravitacijskom transportu na površinskim kopovima
• Author: Mario Klanfar https://orcid.org/0000-0003-1629-873X
• Author: Trpimir Kujundžić
• Author: Darko Vrkljan
• Author's institution: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mining and Geotechnical Engineering)
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mining, Petroleum and Geology Engineering; Mining

Abstract (english)

Analysis of accuracy and calculation applicability of bulldozer's productivity in gravitational transport on open pits has been conducted by comparing computational values obtained by theoretical formulas and results of field measuring. The magnitude of the volume of blade load and the speed of bulldozer's motion, which are the main factors for assessment of machine productivity, have been measured and compared at the same length of transport. Significant deviation of computational specified bulldozer's productivity has been noticed with regard to the ones measured in real conditions. Calculation improvements have been suggested in order to better approximate real exploitation effects by introducing new formulas for the volume of blade load and the speed of bulldozer's motion. The curvature of bulldozer's blade has a substantial effect on the volume of pile in front of blade, and it is not negligible in the calculation. By comparing computational values of different authors, deviations between 3 % and 40 % from measured values have been obtained. The new proposed formula with a 3 % deviation has been proved to be the most accurate. Theoretically calculated maximum speed of bulldozer's motion by means of engine power significantly deviates from the actual measured speed (>49 %). The speed of bulldozer's motion according to the rimpull diagram and the adjusted formula that represents a universal rimpull characteristic of the bulldozer, is applicable in transport where the influence of blade load pushing resistance is prevalent to the bulldozer's speed (deviation <16 %). Bulldozer's speed of motion backwards is more reliable to determine by experience because deviation of computational value (>160 %) introduces a significant error in the productivity assessment.

Abstract (croatian)

Analiza točnosti i primjenjivosti proračuna učinka dozera, pri gravitacijskom transportu otkrivke na površinskom kopu, provedena je usporedbom računskih vrijednosti dobivenih prema teoretskim obrascima i rezultatima terenskih mjerenja. Mjerene su i uspoređene vrijednosti obujma vučne prizme i brzine kretanja dozera, koji su osnovni faktori za određivanje učinka stroja, u uvjetima iste duljine transporta. Uočena su znatna odstupanja računski određenih učinaka dozera u odnosu na izmjerene u stvarnim uvjetima. Predložena su poboljšanja proračuna u cilju približavanja stvarnim eksploatacijskim učincima uvođenjem novih obrazaca za obujam vučne prizme i brzinu kretanja dozera. Zakrivljenost noža dozera ima znatan utjecaj na obujam vučne prizme i nije zanemariva u proračunu. Usporedbom računskih vrijednosti po različitim autorima dobivena su odstupanja između 3 % i 40 % od mjerenih vrijednosti. Najtočnijom se pokazala novopredložena formula s odstupanjem od 3 %. Teoretski proračunata maksimalna brzina kretanja dozera prema snazi stroja, značajno odstupa od stvarne izmjerene brzine (>49 %). Brzina kretanja dozera prema vučnom dijagramu, te prilagođenoj formuli koja predstavlja univerzalnu vučnu karakteristiku dozera, primjenjiva je u slučaju transporta gdje prevladava utjecaj otpora vučne prizme na brzinu dozera (odstupanje <16 %). Brzinu kretanja dozera unatrag pouzdanije je odrediti iskustveno, jer odstupanje računske vrijednosti (>160 %) uvodi značajnu pogrešku u procjenu učinka.

• Keywords (english): bulldozer; exploitation of mineral raw materials; gravitational transport; machines' productivity; mining
• Keywords (croatian): dozer; eksploatacija mineralnih sirovina; gravitacijski transport; rudarstvo; učinak strojeva
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Tehnički vjesnik
• Numbering: vol. 21, no. 3, pp. 517-523
• p-ISSN: 1330-3651
• e-ISSN: 1848-6339
• URN:NBN: urn:nbn:hr:169:980801
• Publication: 2014
• Document URL: https://hrcak.srce.hr/123316
• Type of resource: Text
• Access conditions: Open access
• Created on: 2021-03-22 12:56:30