Podcast
Questions and Answers
What is the load factor if the pounds per cubic yard of loose material is 2,130 and the pounds per cubic yard of bank material is 2,960?
What is the load factor if the pounds per cubic yard of loose material is 2,130 and the pounds per cubic yard of bank material is 2,960?
If a front end loader has an output of 200 BCY per hour and the earth has a swell of 20%, what is the output in LCY?
If a front end loader has an output of 200 BCY per hour and the earth has a swell of 20%, what is the output in LCY?
How many total pounds are required for 18,000 CCY of material considering a shrinkage factor of 10%?
How many total pounds are required for 18,000 CCY of material considering a shrinkage factor of 10%?
What is the total volume in BCY needed for a job requiring 18,000 CCY, given a shrinkage factor of 10%?
What is the total volume in BCY needed for a job requiring 18,000 CCY, given a shrinkage factor of 10%?
Signup and view all the answers
If each truck has a total cycle time of 15 minutes, how many truck cycles are completed in one hour?
If each truck has a total cycle time of 15 minutes, how many truck cycles are completed in one hour?
Signup and view all the answers
What is the total production rate of a fleet of 2 trucks, each with a capacity of 25 LCY, in LCY/hr?
What is the total production rate of a fleet of 2 trucks, each with a capacity of 25 LCY, in LCY/hr?
Signup and view all the answers
How many hours are required to excavate and haul 24,000 LCY if the production of a 3-truck fleet is 216 LCY/hr?
How many hours are required to excavate and haul 24,000 LCY if the production of a 3-truck fleet is 216 LCY/hr?
Signup and view all the answers
What is the swell percentage formula used to calculate swell in volume?
What is the swell percentage formula used to calculate swell in volume?
Signup and view all the answers
What is the cyclic capacity of a front-end loader equipped with a 4 cubic yd blade that completes a cycle in 5 minutes?
What is the cyclic capacity of a front-end loader equipped with a 4 cubic yd blade that completes a cycle in 5 minutes?
Signup and view all the answers
Which unit volume is used to identify material in its natural state before disturbance?
Which unit volume is used to identify material in its natural state before disturbance?
Signup and view all the answers
How long does it take to finish moving 200 cubic yd of soil with a productivity rate of 48 cy/hr?
How long does it take to finish moving 200 cubic yd of soil with a productivity rate of 48 cy/hr?
Signup and view all the answers
Which term refers to the sequence of tasks repeated to produce a unit of output in equipment?
Which term refers to the sequence of tasks repeated to produce a unit of output in equipment?
Signup and view all the answers
What condition of soil refers to material that has been excavated or loaded?
What condition of soil refers to material that has been excavated or loaded?
Signup and view all the answers
What is the primary basis for payment in earthwork operations?
What is the primary basis for payment in earthwork operations?
Signup and view all the answers
What is the productivity when a front-end loader moves 48 cubic yards per hour?
What is the productivity when a front-end loader moves 48 cubic yards per hour?
Signup and view all the answers
Which of the following correctly describes the term 'cyclic rate'?
Which of the following correctly describes the term 'cyclic rate'?
Signup and view all the answers
What is the effective output of the front end loader when considering the swell factor?
What is the effective output of the front end loader when considering the swell factor?
Signup and view all the answers
How many total cubic yards of material does the job require after accounting for shrinkage?
How many total cubic yards of material does the job require after accounting for shrinkage?
Signup and view all the answers
What is the total production rate of a fleet of four trucks with a capacity of 18 LCY each?
What is the total production rate of a fleet of four trucks with a capacity of 18 LCY each?
Signup and view all the answers
If each truck has a cycle time of 15 minutes, how many cycles can each truck complete in one hour?
If each truck has a cycle time of 15 minutes, how many cycles can each truck complete in one hour?
Signup and view all the answers
What is the total hours required to excavate and haul the material with a 2-truck fleet?
What is the total hours required to excavate and haul the material with a 2-truck fleet?
Signup and view all the answers
Considering a shrinkage factor of 10%, how much material must be moved to achieve 18,000 CCY?
Considering a shrinkage factor of 10%, how much material must be moved to achieve 18,000 CCY?
Signup and view all the answers
What is the effective volume of material to account for swell, with a requirement of 20,000 BCY?
What is the effective volume of material to account for swell, with a requirement of 20,000 BCY?
Signup and view all the answers
How long does it take to complete the entire excavation and hauling process with a fleet of four trucks?
How long does it take to complete the entire excavation and hauling process with a fleet of four trucks?
Signup and view all the answers
Study Notes
Equipment Productivity
- This lecture focuses on earthmoving equipment, but similar calculations apply to other operations.
- The goal is to calculate cost per unit for estimating new jobs.
- The method involves finding the units produced per hour by a system (Units/Hr), which determines the system's productivity.
Learning Objectives
- Explain terms related to equipment productivity.
- List three states of soil and convert between them.
- Calculate the productivity of an equipment fleet.
Machine Characteristics
- Cyclic capacity: the number of units produced per cycle. Factors include machine size and material state.
- Cyclic rate: the speed of an equipment piece. The cycle is a sequence of tasks repeated to produce a unit of output (e.g., a cubic yard).
- Example: A front-end loader with a 4 cubic yard blade completes a load-move-dump-return cycle in 5 minutes.
- Cyclic capacity is 4 cubic yards.
- Cyclic rate is 12 cycles per hour.
- Productivity is 48 cubic yards per hour.
- It takes approximately 4 hours and 10 minutes to move 200 cubic yards of soil.
Three States of Soil
- Bank: Soil in its natural undisturbed state. Often referred to as "in-place" or "in situ". Bank cubic yard (BCY).
- Loose: Excavated or loaded soil. Often referred to as "bulk" or "bulking volume". Loose cubic yard (LCY).
- Compacted: Soil after compaction. Compacted cubic yard (CCY). Payment for earthwork is based on compacted earth.
Volume Relationships
- Volume varies, but mass remains constant.
- Density (Bank) x Volume (Bank) = Density (Loose) x Volume (Loose) = Density (Compacted) x Volume (Compacted).
- Example: 1 cubic yard (bank) = 1.0 cu yd and weights 2,000 lb. Bulking volume could increase this to 1.3 cubic yards.
Relationships Between Three States
- 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
Equipment Fleet Productivity
- A front-end loader can have output of 200 bank cubic yards (BCY) of earth per hour and loads a fleet of trucks.
- Each truck's capacity is known, cycle times are accounted for, and material swell/shrinkage is considered in calculations.
- The required time to process a specific volume of compacted cubic yards (CCY) is also calculated.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the fundamentals of equipment productivity, focusing on earthmoving equipment and its calculations. You'll learn to evaluate cost per unit, understand cyclic capacities and rates, and calculate fleet productivity. Test your knowledge on the principles that drive efficient operations in construction.
