Question

A contractor wants to explore using a 7U blade on a 240 hp dozer. The material is a dry, noncohesive silty sand and must be moved a distance of 200 ft from the beginning of the cut. It is estimated the material will swell 4%, from bank to loose state. Both visibility and traction should be satisfactory. Job efficiency is assumed to be equivalent to a 50-min hour. The U-blade width is 13 ft I in with 3.25 ft of wing width, and a height of 5 ft 1.1 in. The wing angle is 28.0 deg. Assume an average push speed of 3 mph and a return speed of 4 mph. Calculate the direct cost of the proposed earthmoving operation in dollars per bcy. Assume that the O&O cost for the dozer is $89.50 per hour and the operator's wage is $19.00 per hour plus 30% for fringes and workers compensation. 7.7

Can you please solve this one.

Answer 1

The ideal maximum production for D7 blade and must be moved at the distance 200 ft. Refer the graph "Dozing production estimating curve" the ideal production is 430 lcy/hr. The bank weight for this project is 110 lb/cf. Convert the cubic feet to cubic yards P. = 1101' /, x 27x cf су су -29701b/bcy Calculate the loose weight of the material using the relation: 2970 100 -2855.7691b/lcy -28561b/lcy Calculate the material weight correction using the relation: Material weight correction 23001blcy Substitute 2856 Ib/lcy for L

23001b/lcy 28561b/1cy 0.81 Material weight correction For skill operator the operation correction factor is 0.75 For non-cohesive soil, the material type correction factor is 0.8 For slot dozing operating technique the operating technique correction factor is 1.20 For satisfactory visibility condition visibility correction factor is 1.00 Calculate the efficiency factor using efficiencyfactor- 30min the relation: 60 min 0.833 For power, shift machine transmission the correction factor is 1.00 The blade adjustment factor is 1.00. For zero grade, the grade correction factor is 1.00 Calculate the total correction factor as below: m ateri al weight correctionxoperation correction factorxmaterial type correction factor Total correction factoroprating technique correcti on factorxvisibility correction factorxefficiencyfactor xmachinetransmission factorxblade adjustmentfactorxgrade correction factor 0.81x0.75x0.8x1.20x1.00x0.833x1.00x1.00x 1.00 -0.4858

Calculate the production rate using the relation: Productio (LCY)-Total correction factorxideal production 0.4858 x4301cy/hr -208.8941cy/hr Coavert the loose cubie yard to bank cubic yard as below: Production (BC)-208.894ley/h1 121ev bcy су 186.51bcy/hr Calculate the O &O cost for the dozer as below: o8Ocot-" Production BCY) $89.50 /hour Production (BCY $89.50/hour 186.51bcy/hr S0.4799 /bcy Calculate the operator's wage as below: operation wage cost-"Producion(BCY) $19.00/hour $19.00/hour 186.51bcy/hr S0.102/bcy

Calculate the fringes and worker's compensation as below $19.00 hour. 3090 fringes and worker's compensation cost) Production (BCY $19.00 /hour x 3090 186.51bcy/hr -$0.031/bcy Calculate the direct cost of the proposed earthmoving operation in dollars per bcy as below Direct cost-S0.4799Њеу +S0.102 Љсу + S0.031 /bcy S0.6129/bcy

Answer 2

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