Requesting Help On a Project

[HopefulStudent]

Hello everyone, I would like to first introduce myself by saying that I am currently a senior at CSUF studying civil engineering and am currently taking a class on construction management and engineering.

I know that this is a long shot but, as my name states, I am a hopeful student and I am here requesting advice regarding earthwork in a project for the class that is completely hypothetical and made up by our group. If any terminology is used, please forgive me. I will try my absolute best to be as clear and accurate as possible.

We have a lot size of 300,000 square feet, 600' x 500' and on the land we are proposing to build a "steel minimill" that focuses on producing bar steel products. We understand that our land may not suffice for a steel minimill but all that aside, we are just looking for help regarding the earthwork. Now regarding the earthwork...

Essentially, what we have is a 6" stripping layer that we do not need over the entire lot area. This stripping volume came out to a total of about 5700 bcy. I understand that we would have to remove this layer prior to moving the soil for the cut and fills.

For the actual cut and fill volumes, we have a total cut of about 5300 bcy and and a total fill of 4900 bcy. This leaves us with about 400 bcy of soil that will be in excess at the end of the earthwork.

From here, because we are essentially the ones designing the project, we need to now look at the different types of equipment and the quantities of said equipment. This is sort of where my group and I are stuck and are looking for help. I am not looking for any exact answers, just some guidance, or suggestions. After we choose the equipment, we will be ready to do the calculations for the time but yes we need the equipment first.

At this point I am not sure what else to add to this post without digging myself a bigger hole than I may have already dug myself. With this being said, if anyone would be willing to help, I will be attaching all the pdfs of the drawings that I have made and converted to pdfs. I am willing to follow up on any questions that are asked of me. Thank you so very much to whoever reads this and , well, everyone in general and I hope that everyone remains in good health during these trying times.

 

[Cmark]

Earthmoving isn't really my thing but I've been around it long enough to give a few pointers/questions to get started.

First and foremost, what it the ground like. Sand, rock or something in between?
Bank yards and loose yards are not the same thing. What compaction is called for?
Budget?
Timeframe?

Do a google search for Caterpillar performance handbook pdf. Lots of good information pertaining to earthmoving.

 

[redneckracin]

Well, that's an interesting way to show cuts and fills. I normally have a plan set and cross sections or just use my site modeler. What kind of time frame do you need to have the materials moved? Technically a teaspoon will work if you have the time. Your schedule and budget will do as much to dictate your equipment as the total yardage will. Do you have to over excavate any weak subgrade? Do you have to proof roll material? or does it have to be nuked? Are you not assuming any wasted material due to poor qualities? Muck for instance. Don't forget, that 6" of topsoil that you are stripping needs to be put back. Also, with your construction phasing, will you require stockpiles? Do you have to lay any pipes or inlets before its at final grade or after?

I'll quit complicating things!

 

[HopefulStudent]

Thank you for the reply!

Earthmoving isn't really my thing but I've been around it long enough to give a few pointers/questions to get started.

First and foremost, what it the ground like. Sand, rock or something in between?
Bank yards and loose yards are not the same thing. What compaction is called for?
Budget?
Timeframe?

Do a google search for Caterpillar performance handbook pdf. Lots of good information pertaining to earthmoving.

In regards to the soil, it can be whatever we choose it to be because it is hypothetical. Perhaps, we will just consider the land is sandy.

In regards to the compaction, we can also choose the percent compaction(?) that we would like. I guess this means we would need to assume the unit weights of the soil and the compacted unit weights of the soil?

Budget and timeframe-wise, we plan to just make a couple of different hypothetical setups that would show, I guess, our analysis in coming up with a plan that is more efficient than another.

For example, in the end, I hope that we can be able to say something like this: If we use X and Y amount of machine A and machine B, it will take [insert duration] amount of time and [insert cost] dollars over using these other machines.

For the purposes of this assignment, cost values are not necessary but I do understand that, in practice, it would be one of the main considerations.

Yes, I did see someone mention that same manual and have a copy that I am looking through. Thank you for that!

 

[HopefulStudent]

Well, that's an interesting way to show cuts and fills. I normally have a plan set and cross sections or just use my site modeler. What kind of time frame do you need to have the materials moved? Technically a teaspoon will work if you have the time. Your schedule and budget will do as much to dictate your equipment as the total yardage will. Do you have to over excavate any weak subgrade? Do you have to proof roll material? or does it have to be nuked? Are you not assuming any wasted material due to poor qualities? Muck for instance. Don't forget, that 6" of topsoil that you are stripping needs to be put back. Also, with your construction phasing, will you require stockpiles? Do you have to lay any pipes or inlets before its at final grade or after?

I'll quit complicating things!

First off, thank you for the reply! I would definitely be interested in a lot of the details you mentioned but unfortunately, given the remaining duration left to complete this project, for the class, I do not think that I will be able to consider a lot of those things at this time.

Regarding the teaspoon, I believe that is what our professor is essentially trying to get us to avoid. Essentially, we have X amount of land and we are trying to find right combinations of types and quantities of equipment so that we don't end up with the teaspoon situation. Likewise, we also don't want cut our cake with a shovel, or bulldozer.

I am going to apologize ahead of time because, I do not think I have the knowledge or capacity to answer many of the questions you have asked. However, if it may help, we can assume ideal cases in all situations so that any calculations can be simplified and hopefully streamlined.

I do have a question regarding the stripping, however. In class we learned that the stripping, or topsoil, is essentially unusable for structural purposes. Having this in mind, and knowing that we would ultimately not have any landscaping in the final design, we decided to just consider it to be soil that would be hauled off the site, never to be seen again (by us).

Thinking a little more about this I guess I can form a better explanation of our setup:
1. I understand that the equipment available and budget available would dictate, as you said, just as much as the yardage.
2. However, for the purposes of the project, the yardage is really the only governing factor.
3. I apologize for repeating myself, but I think, this means is that we can come up with different setups with different amounts and types of equipment. Also, we should be aiming for very practical setups, possibly based off the fleet of existing companies.
4. This is essentially the point that my group and I have reached in the project.

I am not sure if this helps to clarify enough or there may be more information needed but it is all I have for now.

 

[CM1995]

5K bank CY's is not that much.

330 sized hoe, 2 - 25 Ton artics, D6N or R spreading and an 84" vibratory roller compacting. Have the trucks drive in top of the proceeding fill lift in order to speed spreading with the dozer and help with compaction. Your trucks should never back up if you can help it - always go in a circle with haul trucks. 2 weeks tops for stripping, cutting and filling. Compaction spec's should be 98% of the proctor with +/- 2% optimum moisture for an industrial building.

 

[AzIron]

Around here a guy would drop 2 621 scrapers a blade and water truck if the ground is real sandy then you might us 623 so you can elevate your load into the bowl no need for a roller with scrapers just dont dry dump your material process in the cut as you pick it up

The only catch is your top soil to strip 6 inches you need a 613 or 623 elevator dump it in a stock pile and slam trucks with a loader
Another way would be 627 push pulls would go pretty good if it's not like running sand

Either of those options would make that project a week or less

 

[HopefulStudent]

5K bank CY's is not that much.

330 sized hoe, 2 - 25 Ton artics, D6N or R spreading and an 84" vibratory roller compacting. Have the trucks drive in top of the proceeding fill lift in order to speed spreading with the dozer and help with compaction. Your trucks should never back up if you can help it - always go in a circle with haul trucks. 2 weeks tops for stripping, cutting and filling. Compaction spec's should be 98% of the proctor with +/- 2% optimum moisture for an industrial building.

Thank you for the reply!

In regards to using an excavator for digging out the pit for the foundation (mat) of a building, would the land first be graded to the desired elevations and then the pit excavated? I know this may be a very dumb question but I just want to make sure if this is correct or not.

Also, I am not completely familiar with the equipment models but, just to clarify...
The hoes and artic. trucks are responsible for the excavating and haul of the material.
The D6N , which is a dozer is used just for spreading out the land dumped by the trucks, preferably not through backing up as to keep the cycle flow more continuous and fluid.
The compactor is, well, responsible for compacting any fills to the desired/required densities.

Is this correct?

Regarding the compaction, if the land underneath the excavated land is at the desired density, compaction is not needed?
However, for any fill areas, compaction is required?

I am sorry for the many questions but once again, thank you for the reply! All these replies are quite helpful.

 

[HopefulStudent]

Around here a guy would drop 2 621 scrapers a blade and water truck if the ground is real sandy then you might us 623 so you can elevate your load into the bowl no need for a roller with scrapers just dont dry dump your material process in the cut as you pick it up

The only catch is your top soil to strip 6 inches you need a 613 or 623 elevator dump it in a stock pile and slam trucks with a loader
Another way would be 627 push pulls would go pretty good if it's not like running sand

Either of those options would make that project a week or less

Thank you for the reply!

I believe that our group decided to go with a clay that is dry for our land, however that may change things in regards to you reply.

Could you elaborate, if possible, the process that you described.

If it is a hassle, it is quite alright but I have only just learned of the different types of equipment so the exact functionality of all the different types of equipment is still not very clear to me.

Once again, thank you for the reply!

 

[HopefulStudent]

First of all thank you to everyone for the replies!

For anyone interested, I would like to share some updates regarding our project.
I have attached a copy of the calculations described further down in this post.

For the land, we decided that the land we would be working with is a dry clay.

I have attained a copy of the CAT Performance manual and have been using it as a reference. Moving on...

Because our professor wants us to explore different options, efficient or not, I decided to see what it would take to just push the land using dozers.

I saw a reply mentioning a D6N dozer for spreading and when I looked up the equipment, I learned that it could also be used for pushing earth given the use of the correct blade.

From here, I went and found a general production of one dozer in both lcy/hr and bcy/hr.

These were some of my assumptions/generalizations and information:

1) The dozer was a D6N XL with a 6.15 cy capacity SU blade.
2) For the push distance, I just used a value of 300 feet, for now.
3) For push speed, I used an average value of 2 mph, checking to make sure it could push the weight of the soil at capacity.
4) For return speed, I used 6 mph.
5) I considered a 0.05 maneuver time and a 50 minute work hour.

From these, I got a production value (for 1 dozer) of 85.65 bcy/hr.
Next, I fount the time it would take 1 dozer to push the 5333 bcy a distance of 300 feet. This value turned out to be 62.27 hours.
In units of working days (choosing 7 hours/day), I arrived at roughly 9 days for 1 dozer to push the land.
For 2 dozers, I got roughly 4 and a half working days.
For 3 dozers, I got roughly 3 working days.
For 4 dozers, I got a little over 2 working days.

Now here are some questions I have:
Do these numbers make sense? Are they practical?
Would you actually use this many dozers, or would you more or less? I guess You wouldn't use more unless you needed to meet some other time requirements.
Do my calculations really reflect the situation that I described where I have a 5333 bcy pile of land and X dozers pushing the land 300 ft?

Once again, I have attacked a copy of my calculations to this post.

I hope that my results are not total rubbish and that they are reasonable. Any feedback. suggestions, or comments would be greatly appreciated. In the end, I'm just here to learn.

Thank you everyone!

 

[AzIron]

Figure an 8 hour day gets you at best 7 hours of production realistically 6 and a half true production the rest of time is spent screwing around setting up lasers GPS or going to the j john and double checking stakes and layout

As far as using scrapers they are self loading if your in good clean clay that cuts you in paradise and can self load with a single engine machine non assisted to load but it requires a blade around to keep things level and finish you could get by with a dozer on gps to level and finish but it cost more to run and is slower in finish applications to run with scrapers

Scrapers cant export dirt or load trucks off site so they build a stockpile to be hauled off by loader and trucks witch means you have touched your export dirt twice that cost money so that is a negative but production and cycle times scrapers kill an excavator and truck especially on short hauls

Scrapers are big and heavy so they can wheel roll as they drive thru the fill for compaction so no need for a roller

This scenario really all comes down to ground conditions if your in alabama your probably not using scrapers they tend to submarine into that thick heavy clay mud if your in AZ you wouldn't have a problem with mud more likely your problem is rock

The dozer bet might be the way to go I have been on jobs where the push was just under half a mile with a dozer because it was still cheaper than excavator and trucks and the rock was so big you didn't want to use a scraper if your in gummy mud a dozer is not making full production clay sticks to other clay making more friction

Excavator and trucks is a little hard to be efficient on a 2 foot cut you would probably need a 5 foot wide bucket to load trucks efficiently and to slam trucks your still cleaning up behind the ex

I think if your under 800 feet dozes are still one of the cheapest options as long as your not in sand it will kill the under carriage

Small jobs pose efficiency problems hauling in 2 d6 size machines for 3 days is probably more expensive than the schedule is worth for a 2 to 3 day gain mob fees can end up being half a small job

 

[KSSS]

If the soil conditions are appropriate, I would opt for CaseIH quad tracks and a set of pans. When the conditions fit a pan, they are faster and cheaper.

 

[cuttin edge]

would scrapers be cost effective on a 600x500 lot. Wouldn't it be like digging a basement for my house with a 700 Hitachi? I'm thinking more like a D7 and a 950 with some tandem trucks to strip the top 6 inches. Maybe a 350 excavator to dig for the pad. You have to look at what it costs to move and demove the machines as well. Even the excavator and the dozer for stripping and loading. Moving scrapers, and wiggle wagons on and off site can be expensive. In my mind, 2 machines with tandem trucks is the way to go. That's how we would do it anyway. Maybe a smaller machine for backfilling the pad and digging services. A compactor is not that big of an expense if they want one.