Loading the lesson
Loading the lesson
Search AllRounder.ai
Search the courses, subjects, tracks, games and features, or jump straight to a page.
Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we will discuss the productivity curves and the ideal conditions under which they apply. Can anyone tell me why we might need to adjust these curves?
I think it's because real project conditions might differ from those ideal ones.
Exactly! For instance, if a machine is expected to work for 60 minutes but actually only works for 50, how would we find a correction factor?
We would calculate the efficiency as 50 divided by 60, right?
That's correct! The efficiency here is 0.83, meaning we need to apply this factor when estimating productivity. Remember, efficiency is crucial and can be remembered with the acronym 'E.F.' — Efficiency Factor.
Now, let's talk about soil density. What can happen if the soil density differs from what's specified in the productivity curve?
We have to calculate a correction factor based on the difference, right?
Yes! For example, if the ideal condition is 1365 kg/m³ but our actual soil density is 1750 kg/m³, we need to adjust accordingly. The correction factor here would be 1365 divided by 1750.
So that would mean our productivity is reduced because denser soil is harder to move?
Correct! A higher density means lower productivity, which is why we also discuss different material types, like the differences between cohesive and non-cohesive soils.
Let's discuss operator skill. How do you think the skill level of an operator influences the productivity curves?
If the operator is not very skilled, the productivity will be less than what the curves show, right?
Right! So we often use a correction factor for average skill. Now, what about different dozing methods—can anyone name a method that could enhance productivity?
Slot dozing! It seems to help reduce how much material spills over.
Exactly! Slot dozing increases productivity—remember, 'S.D. for Success' when you think of this method.
Lastly, let’s factor in cost estimation. How do we calculate cost per bank meter cube?
By dividing the hourly cost by the productivity rate in bank cubic meters, right?
Yes, that's a crucial formula! If we know our hourly cost is ₹1450 and our productivity in bank meters is 55.63, that would yield what cost?
₹26.06 per bank meter cube!
Great job! This cost estimation is vital for project bidding. Remember, think 'C.C.E.'—Cost Calculation Essentials.
Correction factors are essential for adjusting productivity estimates to real working conditions.
Job efficiency directly affects how machine productivity can be calculated.
Soil density must be considered when comparing productivity curves with project conditions.
Operator skill is a significant factor in estimating productivity.
Different dozing methods can lead to varying levels of productivity.
For every muck that's hard to tow, A correction factor helps us know.
Once upon a time, a bulldozer worked under the sun on hard soil. It struggled until a wise operator adjusted the machine’s settings, and suddenly, the work flowed smoothly—all because of the correction factors that made it easier!
S.O.F.T. - Soil density, Operator skill, Fundamental efficiency, Type of material - remember these factors that impact productivity!
FOCUS: Find Operator, Check Use of soil - a guide to remember the productivity checks!
Term
What is Job Efficiency?
Click to flip
Term
Define Material Type.
Click to flip
Term
What is a Correction Factor?
Click to flip
Term
What is Slot Dozing?
Click to flip
A numerical value used to adjust productivity estimates based on varying conditions.
The ratio of actual operating time to the expected operating time, typically expressed in minutes.
The mass per unit volume of soil, typically expressed in kg/m³, which affects the difficulty of movement.
Classification of soil (cohesive vs. non-cohesive) that influences how easily it can be moved.
A dozing method that enhances productivity by minimizing material spillage.
This section discusses productivity estimation for earthmoving operations, emphasizing correction factors for various conditions.
In this section, we explore the impact of correction factors on productivity estimation in earthmoving operations. Key aspects like machine efficiency, soil density, and operator skill are examined, highlighting the significance of applying appropriate adjustments to ensure accurate productivity and cost estimates.
In this section, we delve into the estimation of productivity for earthmoving operations using bulldozers. The section emphasizes that the productivity curves are valid only under ideal conditions, and corrective measures must be taken when conditions deviate from these norms. Key factors affecting productivity include:
Job Efficiency: The operational efficiency of the machine, especially when it works less than the full hour.
Soil Density: The difference between the soil densities used in productivity curves and the actual project conditions must be addressed to correct productivity values. For instance, if the ideal curve is based on a soil density of 1365 kg/m³ but the project soil density is 1750 kg/m³, adjustments must be made.
Operator Skill Level: The operator's experience plays a crucial role. The curves may assume an excellent operator; hence if the actual operator is average, a reduction factor is applied.
Material Type: Non-cohesive materials affect productivity differently than cohesive materials. The correction factor often decreases productivity.
Dozing Methods and Conditions: Specific techniques like slot dozing can enhance productivity, while others may hinder it based on visibility or grade percentage.
The calculation processes for the correction factors based on these conditions are outlined, ultimately leading to adjustments of the maximum production rates to derive costs per bank meter cube for the earthmoving operation.