Fixing The "low Bid"

dayexco

had a contractor that moved in here about 10 yrs ago, knocked the bottom out of our market, virtually was low bidder on everything he touched. 5 yrs later, he's broke, moved on. in his wake, he's left 1000's of feet of ditch that never got compacted properly, and now, the city and private property owners are losing their streets, parking lots at quite an expense to them. all because they wanted the low bid. these pictures are of a church that was built the last summer he was in town, he of course was low bidder for site utilities. their parking lot is nothing but a train wreck right now. they've hired us to cut/pull the asphalt, dig down to the pipe, haul the muck away, haul in good material, and recompact it so they can repave the lot. i should be thankful for the work, but yet peesed because as a taxpayer, we're having to pay to have somebody come in and correct the mess.

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someday, i'll be as patient as Nick.

dayexco

few more

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someday, i'll be as patient as Nick.

Darwin

work done right the first time=it will cost a fair $

work done twice = an even greater price

john1066

The problem will still be there tho the way the system is they will always go with the low bid.

sparehair

Cmon anybody can dig a ditch. I got a shovel. Dig a hole and put the dirt back what so hard about that. I'll take the lowest bidder!

funk5stacks

our inspectors would never let us get away with dirt backfill in a parking lot/ roadway. is there even a stone base under that asphalt?

cexcavation

Ditto here......that was the first thing I thought when I saw those pictures. Around here those trenches would have to be backfilled with rock all the way to the top, and the asphalt would have to be "T cut" in order to leave a ledge on both sides. Then they would have to hit it for compaction tests not to be less than 95%. Looks like a fun job Day

dayexco

i would question your inspectors expertise in soils.


why would you put in a dissimilar soil for your back fill material? were you to put a granular material for the whole excavation in an area where the original soil is a cohesive clay....in the winter months, the clay adjacent to the excavation will expand when freezing and the granular in the excavation stays put, leaving a 2-3" depression" where the excavation is, and will not go back down until the frost goes out in the spring. you have a reoccurring problem annually with that. what was done here, is we filled the excavation to w/in about 6" of the top of the asphalt with the clay. then we trimmed it back out to 1' down and compacted what we call "class 5" material, which is a crushed/manufactured gravel. when the paver comes, he'll dig out the top 3" and lay his mat leaving a 9" granular sub base for the asphalt.

as far as the density testing is concerned. we leave that up to the owner. we encourage them to do so, and if they refuse, make them sign a disclaimer, but some property owners are reluctant to add that additional expense to their projects. the problem with this particular excavation, is that it was never compacted, just a dig and doze, and it wicked up moisture from the surrounding soil, and they have a problem with their roof drains dumping right into the area of these excavations, filling the voids in the soil of the uncompacted soil causing it to fail and settle. the soil taken out of the excavation was at approximately 23% moisture....as you know, beyond the bubble gum phase, it was pure mud. the optimum for this material was 16%, and we were able to find surplus material that was at the +/- 2% allowance from a basement excavation 2 blocks away.

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someday, i'll be as patient as Nick.

Williams Ex Co

Gene, Can you 'overcompact' with that type of plate compactor? Enough to do damage to the utilities below? Most of what I do for the local municpality as far as trench work goes is done with a jumping jack in about 6'' lifts..... Wondering if I could use a smaller version of that compactor on my mini hoe....

dayexco

if you bed your pipe in sand or rock....i wouldn't worry about it. they're a GREAT time saver...it'd be my bet, that if you have one demo'd....you won't let the salesperson take it from the job....i REALLY recommend the Allied

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someday, i'll be as patient as Nick.

dayexco

we got about 1/2 done with the job, and my son suggested having the line televised to make sure we weren't moving the pipe around....lucky enough, it was in the area we hadn't done, but the 8" pvc line in 80' of it, had .92' sag in it. couldn't get his camera through it. pastor comes out, asks if it possible that the sag made all the toilets not want to flush properly. DUH! the line up to the point we're going to repair/replace....had some 2" deep "duck pond sags" along the way, but the church says they're going to try and live with that. man, this is sad 5 yr old church, having to tear up their parking lot, replace the sewer.

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someday, i'll be as patient as Nick.

tgeb

Thank goodness the sag was not in the areas you had already completed.

You probably would have been held accountable for that, good move getting the video in there when you did.

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Tom

www.gebcon.com

PipeGuy

why not a sheepsfoot trench compactor? soil seems plenty well-graded for it to be very effective.

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Fortunately I keep my feathers numbered for...for just such an emergency. -Foghorn Leghorn

earthmover

Pipeguy I was wondering the samething. I use sheepsfoot trench rollers all the time.

funk5stacks

standard drawings for the city requires DOT approved granular back fill (in pavement, ROW) that is tested by them while we back fill and must also meet their moisture requirements, which typically requires adding water. we still use a hoe pack in green areas to prevent settling and the mess you had to deal with.

dayexco

apparently, our what we all a clay/cohesive soil differs from that in the rest of the US. our excavators are all equipped with quick couplers, and auxillary hydraulics....for us, the sheepsfoot will give us faster/better results compaction wise "if" the soil conditions warrant it.....with our particular soils...the only way to make a wheel work in a cohesive soil..is to have it a minimum of 2 points below, maximum of 4 points below optimum moisture wise.....it's been our experience...that if close to optimum....to just run the vibe plate and be done with it. optimum moisture in our cohesive soils and a packwheel.....is like trying to roll bubble gum.

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someday, i'll be as patient as Nick.

dayexco

btw paul..."if you're looking for a vibe plate and your 2 and a 1/4 have aux hydaulics...i'll sell you a NEW vibe plate for it....i paid 13k for a new allied......this is a rockram, for $3500....just need hoses and 4 bushings. this unit is waaaaaaaaaaay too big for a mini.

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someday, i'll be as patient as Nick.

dayexco

thought you guys might like to see a pic of the sag. we never touched the elevation of the pipe shown here at all...all we did was dig along both sides, and bring rock back up so we had a decent/dry place to stand and work. we had to wait for ins. adjusters to show up and take pics for the church.

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someday, i'll be as patient as Nick.

Little

Looks good Day. All we use are the excavator vibrators they are great. Williams, using the vibratory machine plate, we generally stay a min. of 2.5 to 3ft above the pipe before using it. Around the pipe we jumping jack both sides where necessary.

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Commercial Construction, Central Jersey

The Cleaner

I agree... large compactor plates are very powerfull and you have to leave several feet above the pipe to not impact it too much. One time I was compacting an area and burst a water line underground. Had no Idea it happened so we left for the day and came back to find our entire area flooded with water.