Expert: Dan Griffin - 2/8/2008

Question
QUESTION: sir i want to know about the method for estimating earthwork for mounds and what is this dead man method

ANSWER: All earthwork amounts to cubic measurement of earth to be moved or changed.  Because of complex geometric shapes involved, earthwork quantities are usually guesstimates, though GPS and computer graphics is making it quite a bit more precise.  A mound sounds like a hemisphere to me, so the equation for the volume of a sphere is V = 4/3 × pi ×r3 where the radius would be the approximate height of the hill in question.  Divide the answer by two if you are only talking about the mound above ground.

Earthwork is cheapest if you can keep it on one site and put high spots in low spots without hauling dirt in or out.

Deadman is a term used most often for an earth anchor secured far back into a hillside that is attached to a wall to give additonal strength to the wall to prevent the hill pushing the wall over.  These can be buried timber, screwed in earth augers, drilled and grouted cable, and many other systems.  You would need to be more specific for further information.

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QUESTION: thanks for ur reply sir
but i am still unable to solve the question which states
EARTHWORK FOR THE MOUNDS IN THE LANDFORM WORK IN A LANDSCAPE IS ESTIMATED BY :-
1. AVERAGE END METHOD
2. BORROW PIT METHOD
3. DEAD MAN METHOD
4. PRISMOIDAL METHOD

of these i got the information for 3 except the dead man method

bt as per your answer i couldn't relate how the deadman method is linked with earthwork

as per my search i think the answer is prisoidal method as i gives the accurate, whereas average end also can be used but its not that precise

borrow pit as far as i could understand is for pits

can u please help me by providing the correct answer and give a breif about these methods

Answer
Pagya,  This forum is not here to answer your homework questions.  It sounds like you are taking a surveying class or a civil engineering course.  If you are taking a landscaping course I don't see you using the prismoidal or average end method unless this is a PGA golf course.  If it is a golf course you will most certainly be using the computer type data, if it is a decorative berm in a fancy front yard, you will doing by the seat of your pants(age, experience, and eyeball).

Earthwork estimating is really a matter of scale.  The earthwork necessary to make one residential lot buildable will not warrant any of the text book methods, a man with experience looks at the project and guesses how many days and how much equipment will be required to perform the tasks.  The work is much more influenced by access (mobilization and mechanization), haul routes, and weather.  The earthwork for a major shopping center or a highway demand the estimating care that you are studying.  These jobs are large enough to not be so affected by the small variables which will average out over time, but are very much subject to cubic volume of work.  Each dozer, dump, dynamite blast, and shovel is capable of moving some known quantity of material, in a fairly well known amount of time, using a known amount of fuel and manhours.

Note that all methods require a substantial correction for what I call the fluff factor.  The fluff factor is different for each type of spoil.  Mother nature keeps a typical clay soil compacted to about 88% Proctor, when you dig it out it has a much greater volume and you cannot take out one cubic foot and haul off one cubic foot, you will be hauling off quite a bit more.

I am in the construction business, so I know and use the borrow pit method if it is a large enough job to not simply perform based on experience.  I would consider it the most common in my trade.  It has nothing to do with a pit in the ground.  Establish a grid of a known dimension appropriate to the size of the job, shoot elevation on the grid corners, determine if it is a cut grid or fill grid, calculate the volume.  Add all cuts, add all fills, see if you are bouncing the site, hauling off, or bringing in.

I can remember studying the average end and prismoidal stuff, but I have not ever used either, other than as school work.  These would be much more useful in highway type work.  I don't remember that one or the other was more accurate.  These methods are done with total station information and computer software these days, it would amaze me if anyone is doing this work with ruler and calculator anymore.

I am not familiar with anything called a deadman method of volume estimating and suspect it is a red herring type answer on a multiple guess test.

Here is some web information:
<http://courses.washington.edu/cive316/lectures/lecture7/sld013.htm>
<http://www.civil.ubc.ca/courses/civl235/Lectures%20-%20Student%20Access/Civl235->