Compaction that passes a 95% Procter density test?

[JBGASH]

We got a sewer job consisting of appox 800' and several manholes at a State of Mo. facility. The specs call for 95% compaction in all trenches and 98% in all pavement and road areas. The soil type is a clay loam with some moisture content to it. I have a vibratory plate compactor on a rubber tired hoe but am needing a quicker & better method. Any ideas or comments would be helpful. Thx Jeff

 

[Tones]

Wacker double drum vibrating sheeps foot trench rollers work well if the trench is wide enough and you don't get any lamanation. A compaction wheel on a hoe is also a go for compacting soils below subgrade and no hoses to couple if you have a quick hitch, just place the spoil with the bucket, unhook the bucket, couple the wheel and so on. Its about the fastest method of trench compaction I know and still passes the tests. If you haven't come across these things before, Google images compaction wheels for excavators

 

[monster76]

https://www.sunbeltrentals.com/equi...0250/plate-tamper-reversible-900lb-24in-wide/

I have a plate compactor like this and i ussually have a laborer push it around as i backfill

 

[grandpa]

It all depends on your soil type. The testing company will take a soil sample or two of the material to be tested so they can get a base line for the tests. I've found in sandy soil a smooth drum out packs a sheepsfoot, but in clay type soil the latter moves to the head of the class. Also, optimum moisture in the packing soil will be necessary.

 

[old-iron-habit]

For hand work we have found that a vibratory walk behind normally out performs a jumping jack in tight quarters. It is essential that the testing lab take a proctor and test the material to insure they are using the right setting on the test instrument. Optimum soil moisture is also critical as previously stated. Be careful to not get to much moisture, but insure you have enough. For machine work the vibratory smooth drums work seem to work the best. Check you lift spec. Most specs call for 6" lifts when looking for 95% compaction.

 

[humboldt deere]

I think I've worked some similar material. If we had a hard time getting 95 we would bring the moisture content a little past optimal, compact it, and then let it sit in the sun all day. The next day it would be cracked open and we would recompact dry and we could get 98-100 using a small ride on sheepsfoot. Are you testing with ASTM method?

 

[mowingman]

Is that 95% on a "standard" or a "modified" soil proctor test. The modified test is a LOT harder to meet the specs on. I vibrator plate will probably not get you where you need to be on either test method. As a former geotech engineer, I have run many failing tests on field soil compaction, and angered many job superintendents in the process. You an only imagine how well it goes when a 22 year old "hotshot" soils engineer tells a 50 year old project super. to "tear it all out and start over":shf

Jeff

 

[JBGASH]

It is a "standard" proctor test that is called out in the specs. What is the difference of the two ?

Is that 95% on a "standard" or a "modified" soil proctor test. The modified test is a LOT harder to meet the specs on. I vibrator plate will probably not get you where you need to be on either test method. As a former geotech engineer, I have run many failing tests on field soil compaction, and angered many job superintendents in the process. You an only imagine how well it goes when a 22 year old "hotshot" soils engineer tells a 50 year old project super. to "tear it all out and start over":shf

Jeff

 

[dayexco]

engineers determine the optimum moisture content for a reason. proper moisture is like a lubricant in an engine. just allows the soil particles to compress with less effort and more consistency. optimum moisture content is your friend.

 

[Multiracer]

If you can use the newsome wacker type double drum sheeps foot please do yourself a favor and get used to one. Some are even remotely run so the laborer can stay out of the cut while you fill with lifts.Plate compactors will not get you to 95% with any depth. Lift in small amounts and increase the depth of your lifts as the soil tester passes the first few lifts.
Your pavement areas should require a compaction using stone ?
Good luck and do not **** the compaction tester off on the first day !

 

[dayexco]

If you can use the newsome wacker type double drum sheeps foot.Plate compactors will not get you to 95% with any depth. Lift in small amounts and increase as the soil tester passes the first few lifts.
Your pavement areas should require a compaction using stone ?
Good luck and do not **** the compaction tester off on the first day !

we achieved density consistently with our allied hoe pack. vibe plates work extremely well where soils are a point or two over optimum and you can't run a sheepsfoot because it balls up like bubble gum.

 

[joispoi]

How wide is your trench? Can you put a vibratory drum roller in the trench? It's already been mentioned a couple of times, but moisture content is critical. This time of year, you probably don't have to worry about it being too dry. But rain can make it just about impossible to achieve 95%. Check the weather before you open anything up.

If they're testing compaction, they've done a proctor test and can tell you what the optimal moisture content is. A moisture meter doesn't cost much and will tell you what you're up against before you start.

It is possible to get a compaction result over 100%.

 

[mowingman]

A standard proctor and a modified proctor use the same test mold. Standard uses 3 layers of dirt, compacted with 25 thblows/layer, wi a 5.5# drop hammer, with a 12" drop. Modified uses 5 layers in the mold. Each layer is compacted with 25 blows/layer, using a 10# hammer and an 18" drop.
I other words, you beat the heck out of it using the modified method. This makes it much harder to meet the modified spec. out in the field, when putting in fill.
Jeff

It is a "standard" proctor test that is called out in the specs. What is the difference of the two ?

 

[CM1995]

It is possible to get a compaction result over 100%.

I have. It's not uncommon to get numbers a few points over 100% as the fill material can change slightly from the material used for the proctor. Conversely, I've gotten low numbers when material is compacted - no movement under a loaded dump truck.

JB, who's paying for the testing? I have one testing firm I do a lot of work with and it does make a difference if you have a relationship with the testing company. This doesn't mean any funny business goes on but it allows a more proactive approach when the numbers aren't meeting spec, instead of the tech just saying it failed, gets in his truck and leaves.

In the areas not in pavement do you have enough room to lay the trench back? What's the depth of the trench? What I have found is the quickest way to backfill and compact is to lay the trench open wide enough to get a 533E compactor in the trench, the bigger roller will compact quicker and allow deeper fill depths. I'll use a track loader or dozer to lay in the backfill while the track hoe is digging more mainline. I like this method as it allows a wider more cohesive backfill that helps eliminate any settling later on.

If I have the room, this is how I like to backfill -

View attachment 113584

In the pavement areas I would figure solid stone backfill.

What's the backfill requirement directly around the pipe - how much stone above the pipe?

 

[JBGASH]

CM, I will be hiring and paying for the testing.
The trench depths range from 4 to 16' deep. The deep trenches will be dug with a 48" bucket and all other a 36" bucket. Trench Saftey boxes and benching will be used to OSHA specs.
The pipe has 6" under and min of 6" over the the top of 3/4 clean rock. All road and pavement areas are back filled with AB-3 base rock.
We have did 3 sections of shallow depths done and will be getting the tester to come this week to see if we are close or have the 95% on them, I suspect we do not.. I like the idea of using a 533

 

[dayexco]

we ran 2 excavators, one dig, one compact. pulled boxes, kept excavation narrow as possible. anything over the depth of the box was OSHA'd and wheel rolled in with front end loader.

 

[CM1995]

16' is a deep trench but if you have the area to lay it back it still may be the best option. Most of the storm sewer we install is 4-8' deep which lends itself real well to the lay back and large roller type of compaction.

It's just so labor intensive and time consuming to compact with plate tamps or jumping jacks. Add the depth and you're tying up trench shields and a machine to place the backfill material and move the shields.

Even if you use an excavator mounting tamp of any kind, the tech still has to get in the trench to do a test.

 

[JBGASH]

Dayexco, did u dig it wide enough to get a wheel loader in the trench? Did u have compactor on the second excavator? If, so what type?

we ran 2 excavators, one dig, one compact. pulled boxes, kept excavation narrow as possible. anything over the depth of the box was OSHA'd and wheel rolled in with front end loader.

 

[JBGASH]

Cm, the deep parts, there is plenty of room to dig as wide as needed. The shallow parts are space limited.

16' is a deep trench but if you have the area to lay it back it still may be the best option. Most the storm sewer we install is 4-8' deep which lends itself real well to the lay back and large roller type of compaction.

It's just so labor intensive and time consuming to compact with plate tamps or jumping jacks. Add the depth and you're tying up trench shields and a machine to place the backfill material and move the shields.

Even if you use an excavator mounting tamp of any kind, the tech still has to get in the trench to do a test.

 

[CM1995]

Cm, the deep parts, there is plenty of room to dig as wide as needed. The shallow parts are space limited.

I would over dig and compact with a ride on roller, it'll go faster and be easier to achieve density.