Productivity rate for Embankment Fill

Hi Guys,



To make the information useful to our friend who asked, the summary is that in order to determine the productive rates, the following parameters must be determined:



1. Type of Machines used (size, age, condition).

2. Type of soil and terrain.

3. Method/ Sequence of work.

4. Of course worker productivity is alawys an issue.



This is a standard question in most Engineering Economy books.



With kind regards,



Samer

Mike,



Better double chek it is not a a 7-inch 45 rpm Tom Jones record.



I know Tom Jones was a British singer of the 70’s but we never watched the show. It was shown at the same hour a local singer was on TV. My mother always wanted to see the show but at home we practiced democracy where majority rules. My one years old younger brother would say, Mom, the only word he knew. My father would say local talent and so do I, we always won by the count of 3 to 1.



Best regards,

Rafael

Hi Rafael



I worked with a bulk earthworks contractor in the UK for 3 years in the late 1980’s.



It was when I first used lotus 123 to its full potential in developing an average mass haul calculation matrix for cut to fill volumes.



I still have the original somewhere but it is on one of those big acetate floppies.



It was when I was developing a record keeping system that required the foremen to write a simple 3 digit code against each earth movement that I learnt my nickname - The Fat Controller.



Best regards



Mike Testro

Mike,



Very good point, your scientific approach is the correct. Production rates are not fixed.



Even when new scrapers are faster than the older they are somewhat limited, in adittion to the fact new trucks and backhoes are becoming also more efficient. We use them frequently here as our landscape is 75% mountains, on our road design and construction we accommodate for minimum hauling distances, grade-ability becomes a major concern even when empty up the hill.



Good production references should provide you with different scenarios and combination of equipment as to simplify your preliminary estimate. That is why I advocate for references that provide you with the details; usually a brief description of the operation and the crew that includes equipment will do it. This is what is missing at the production rates shown in PP, if neither crew nor methods are provided production can be anything.



Gobinath question is in order, he cannot deppend on production rates as shown in PP.



Best regard,

Rafael

Hi Rafael



Scrapers are more productive on short hauls up to 0.5 km.



Over that there relatively slow speeds become uneconomical.



Best regards



Mike Testro.

Dear Gobinath,



I would also recommend that you check the type and size of machine that you will have on site. This is a Major Factor in determining the productivity rates.



Generally, the bigger the machines, the higher the productivity rates depending on the type of site layout you have.



With kind regards,



Samer

Don’t rule out moving earth with scrapers.

Hi Gobinath



It is not a good idea to leave your email address in the open forum.



Regarding your question the production rate depends mainly on the length of the haul route from your cut or borrow.



Assuming that your excavator can load 120 m3 hr then there is a formula to calculate the number of haul units.



Length of haul km x 2

Speed of haul units kmh

Volume of load m3

10 min loading + 10 min discharge.



You need to balance the number of haul units so that it will carry about 80% of the excavator production rate.



This has to be ballanced by the spreading and compaction rate and this depends on the material to be compacted.



Usually a D6 or D8 will spread the material towing a comaction unit.



Granular material can be vibro compacted

Cohesive clay has to be rolled with a colts foot or similar

Chalk is very tricky and needs special care depending on the moisture content.



Best regards



Mike Testro