Question

A truck will haul an average load of 15 cy, heaped capacity, and loose measure per load. Use average values of swell factors in Table 7.3 on p. 131 of your textbook to determine the volume of the truck in bank measure when the material is sand, ordinary earth, dense clay, and well-blasted rock.

Then, using an Excel spreadsheet, determine the number of trucks required to move material in the following scenario:

A project requires 40,000 cy of compacted fill that must be completed in 32 working days. The fill material will be hauled to the site in 21 cy loose measure trucks. The cycle time for a truck is 40 min. per trip. The swell factor for the earth is 25% and the shrinkage factor is 10%. Assume 8 hours per day and a 45-min. effective hour. Determine the number of required trucks to complete the project in 32 days.

Deliverable:
Upon completion of this project, you will deliver an excel spreadsheet to include:

• Tables of all information (data) given in the problem
• Formulas that reference cells thus creating dynamic formulas that will change if information in the tables changes
• The final answer highlighted in yellow.

Answer 1

Given data:
Haul an average load of Track = L =	15	cy
Sand, Sw = 10% − 15%:
Assume Avg. swell factor = Sw =	12%
Volume in truck, B = L / (1 + Sw)
	B=	13.39	cy
Ordinary earth, Sw = 20% − 30%:
Assume Avg. swell factor = Sw =	25%
Volume in truck, B = L / (1 + Sw)
	B=	12.0	cy
Dense clay, Sw = 25% − 40%:
Assume Avg. swell factor = Sw =	35%
Volume in truck, B = L / (1 + Sw)
	B=	11.1	cy
Well-blasted rock, Sw = 50% − 80%:
Assume Avg. swell factor = Sw =	55%
Volume in truck, B = L / (1 + Sw)
	B=	9.7	cy

Required production ratefor compacted measure
Given,
Volume for compacted measure = L1 =	40000	cy
Completion time = T =			32	days
Production rate = L1 / T =	1250	cy/day
Production rate of one truck:
Given,
Swell factor for the earth = Sw =		25%
Loose measure payload in truck, L2 =	21	cy
Bank measure payload in truck, B = L2/ (1 + Sw)
		B=	16.8	cy
Shrinkage factor =	10%
Compacted measure payload in truck, C = (1 − Sh) B
		C=	15.12	cy/day
The cycle time for a truck is =   T     =	40	min. per trip.
8	hours per day and a	45	min. effective hour.
Total effective hour = te =	6	hour / day
Daily production rate = P = (C/T)x te x 60 min. / hour
for compacted measure	P =	136.08	cy/day,
Number of required trucks:
Required trucks = (Required production rate) / (production rate of one truck)
Required trucks =	P/C
	=	9	tracks

                                                                                                  Given data:                                             Haul an average load of Track = L =                             15      cy                                                      Sand, Sw = 10% − 15%:                                           Assume swell factor =                   12%                     Volume in truck, B = L / (1 + Sw)                                                       B=      13.39   cy                                                                      Ordinary earth, Sw = 20% − 30%:                                                 Assume swell factor =                   25%                     Volume in truck, B = L / (1 + Sw)                                                       B=      12.0    cy                                                                      Dense clay, Sw = 25% − 40%:                                             Assume swell factor =                   35%                     Volume in truck, B = L / (1 + Sw)                                                       B=      11.1    cy                                                                      Well-blasted rock, Sw = 50% − 80%:                                              Assume swell factor =                   55%                     Volume in truck, B = L / (1 + Sw)                                                       B=      9.7     cy                                                                                                                                                                                                                                                                                                                      Required production ratefor compacted measure                                           Given,                                          Volume for compacted measure = L1 =                             40000   cy      Completion time = T =                           32      days                                                    Production rate = L1 / T =                      1250    cy/day                                                          Production rate of one truck:                                           Given,                                          Swell factor for the earth = Sw =                               25%             Loose measure payload in truck, L2 =                            21      cy                                                      Bank measure payload in truck, B = L2/ (1 + Sw)                                                                 B=      16.8    cy                                                              shrinkage factor =              10%                             Compacted measure payload in truck, C = (1 − Sh) B                                                              C=      15.12   cy/day                                                          The cycle time for a truck is = T =                             40       min. per trip.         8       hours per day and a             45       min. effective hour.           Total effective hour = te =                     6       hour / day              Daily production rate = P = (C/T)x te x 60 min. / hour                                          for compacted measure           P =     136.08  cy/day,                                                                 Number of required trucks:                                              Required trucks = (Required production rate) / (production rate of one truck)                                           Required trucks =               P/C                                      =      9       tracks