CE 222/CEM 201 Life Cycle Engineering & Management of Constructed Facilities PDF

CE 222/CEM 201 Life Cycle Engineering and Management of Constructed Facilities 34 Equipment Productivity LEARNING OBJECTIVES Chapter 15 Explain terms related to equipment productivity List three states of soil and convert among them Calculate the productivity of equipment fleet 2 CONTEXT...

CE 222/CEM 201 Life Cycle Engineering and Management of Constructed Facilities 34 Equipment Productivity LEARNING OBJECTIVES Chapter 15 Explain terms related to equipment productivity List three states of soil and convert among them Calculate the productivity of equipment fleet 2 CONTEXT Focus in this lecture is on earth moving since it is equipment intensive. Similar derivations can be made for other operations. Ultimate goal: calculate cost/unit to use for estimating new jobs. Method: find units produced per hour by a system (Units/Hr).  the productivity of the system. 3 DICTATING MACHINE CHARACTERISTICS Cyclic capacity – the number of units produced per cycle – Size of machine – The state of the material – The unit to be used Cyclic rate – speed of an equipment piece The cycle of an equipment piece is the sequence of tasks, which is repeated to produce a unit of output (e.g. a cubic yard) A front-end loader is equipped with a 4 cubic yd blade. It completes a load-move-dump-return cycle in 5 minutes. (a) What is the cyclic capacity and what is the cyclic rate? 4 cy @ 12 cycles/hr (b) What is the productivity? 48 cy/hr (c) How long does it take to finish 200 cubic yd soil? ~4 hrs 10 min → 4.25 hrs 4 THREE STATES OF SOIL Bank: – Material in its natural state before disturbance – Often referred to as “in-place” or “in situ” – A unit volume is identified as a bank cubic yard (BCY) [cu yd (bank)] Loose: – Material that has been excavated or loaded – Often referred to as “bulk” or “bulking volume” – A unit volume is identified as a loose cubic yard (LCY) [cu yd (loose)] (bulk) Compacted: – Material after compaction – A unit volume is identified as a compacted cubic yard (CCY) Payment is based on compacted earth. 5 THREE STATES OF SOIL 6 iClicker Question Payment for earthwork is based on the volume of soil in which state? A Bank B Loose C Compacted D Any 7 iClicker Question Payment for earthwork is based on the volume of soil in which state? A Bank B Loose C Compacted D Any 8 VOLUME RELATIONSHIPS Volume varies, but mass is constant Therefore: Density[Bank] x Volume[Bank] = Density[Loose] x Volume[Loose] = Density[Compacted] x Volume[Compacted] 9 THE RELATIONSHIPS BETWEEN THE THREE STATES Introductory Example: Material Pounds per Cubic Yard, Bank Pounds per Cubic Yard, Loose Clay, natural 2,960 2,130 Percent Swell = [1 / (load factor) - 1] x 100 where: load factor = (pounds per cubic yard, loose) / (pounds per cubic yard, bank) Volume in BCY x [1 + (swell% / 100)] = Volume in LCY Volume in CCY / [1 – (shrinkage % / 100)] = Volume in BCY 10 TABLE OF MATERIAL CHARACTERISTICS 11 PRODUCTIVITY OF EQUIPMENT FLEET A front end loader has an output of 200 BCY of earth per hour. It loads a fleet of 3 trucks (capacity of 18 LCY each). The trucks haul the earth to a fill where it is compacted with a shrinkage factor of 10%. Each truck has a total cycle time of 15 minutes, assuming no delays. The earth has a swell of 20%. The job requires 18,000 CCY. How many hours are required to excavate and haul the material to the fill? FEL’s output = 200 BCY/hr → ? LCY → ? LCY/hr Job requires 18,000 CCY → ? BCY → ? LCY Production of 3-truck fleet = ? LCY/hr Hours required = ? 12 PRODUCTIVITY OF EQUIPMENT FLEET A front end loader has an output of 200 BCY of earth per hour. It loads a fleet of 3 trucks (capacity of 18 LCY each). The trucks haul the earth to a fill where it is compacted with a shrinkage factor of 10%. Each truck has a total cycle time of 15 minutes, assuming no delays. The earth has a swell of 20%. The job requires 18,000 CCY. How many hours are required to excavate and haul the material to the fill? FEL’s output = 200 BCY/hr → (200 x 1.2) = 240 LCY/hr Job requires 18,000 CCY → 18,000 / (1 – 0.1) = 20,000 BCY → 20,000 x 1.2 = 24,000 LCY Production of 3-truck fleet → 18 x 4 x 3 = 216 LCY/hr Hours required = 24,000 / 216 = 111.111 → 112 hrs Why? 13 iClicker Question A front end loader has an output of 200 BCY of earth per hour. It loads a fleet of 2 trucks (capacity of 25 LCY each). The trucks haul the earth to a fill where it is compacted with a shrinkage factor of 10%. Each truck has a total cycle time of 15 minutes, assuming no delays. The earth has a swell of 20%. The job requires 18,000 CCY. How many hours are required to excavate and haul the material to the fill? A 84 hrs. B 100 hrs. C 112 hrs. D 120 hrs. 14 iClicker Question A front end loader has an output of 200 BCY of earth per hour. It loads a fleet of 2 trucks (capacity of 25 LCY each). The trucks haul the earth to a fill where it is compacted with a shrinkage factor of 10%. Each truck has a total cycle time of 15 minutes, assuming no delays. The earth has a swell of 20%. The job requires 18,000 CCY. How many hours are required to excavate and haul the material to the fill? A 84 hrs. Production of 2-truck fleet → 25 x 4 x 2 = 200 LCY/hr B 100 hrs. Hours required = 24,000 / 200 = 120 → 120 hrs C 112 hrs. D 120 hrs. 15 PRODUCTIVITY OF EQUIPMENT FLEET, EXAMPLE A front end loader has an output of 200 BCY of earth per hour. It loads a fleet of 4 trucks (capacity of 18 LCY each). The trucks haul the earth to a fill where it is compacted with a shrinkage factor of 10%. Each truck has a total cycle time of 15 minutes, assuming no delays. The earth has a swell of 20%. The job requires 18,000 CCY. How many hours are required to excavate and haul the material to the fill? FEL’s output = 200 BCY/hr → (200 x 1.2) = 240 LCY/hr Job requires 18,000 CCY → 18,000 / (1 – 0.1) = 20,000 BCY → 20,000 x 1.2 = 24,000 LCY Production of 4-truck fleet = ? LCY/hr Hours required = ? 16 PRODUCTIVITY OF EQUIPMENT FLEET, EXAMPLE A front end loader has an output of 200 BCY of earth per hour. It loads a fleet of 4 trucks (capacity of 18 LCY each). The trucks haul the earth to a fill where it is compacted with a shrinkage factor of 10%. Each truck has a total cycle time of 15 minutes, assuming no delays. The earth has a swell of 20%. The job requires 18,000 CCY. How many hours are required to excavate and haul the material to the fill? FEL’s output = 200 BCY/hr → (200 x 1.2) = 240 LCY/hr Job requires 18,000 CCY → 18,000 / (1 – 0.1) = 20,000 BCY → 20,000 x 1.2 = 24,000 LCY Production of 4-truck fleet → 18 x 4 x 4 = 288 LCY/hr Hours required = 24,000 / 240 = 100 → 100 hrs 17 LOOK AHEAD More on Equipment Productivity 18