Controlled fill QC 8

[amazing azza]

Starting on a new project. A small sugar cane processing plant in sunny Indonesia. We are scheduled to begin earthworks soon. Going to strip the vegetative layer (20 cm) and do a controlled fill with clay up to grade level for the main building. Total height of fill - 1 to 1.5m. I need help with specifying a QC procedure for this from the owner's side. Our spec is 95% MDD, 20cm lifts.

* Is it realistic to do sand cones on every lift? Several samples?

* I am planning to require a minimum size for the sand cone - 200mm cone with 4L jug.

* What is the proper equipment for compacting each lift? I have seen them simply rolling over the incoming fill with a dozer before. Dozer spreads and drives over, spreads and drives over.

 

[Ron]

I realize that equipment is scarce in your area, but using a smooth drum vibratory compactor on clayey/silty soil will give you problems. First, if the soil is wet (which it is apparently) you will experience a lot of pumping as the vibratory compactor will continue to dilate water to the surface or near surface. Second, if you do dry the soil out, your compaction method will cause crusting of the top surface and prevent compaction at lower levels.

A static sheepsfoot roller would be much better, even one that you can pull around behind a tractor.

You mentioned in your OP that you are required 95% MDD. Which method; standard or modified? Standard is more appropriate for your soil type. Getting 95% MDD with modified will be problematic in that soil.

At this point, I would proofroll the site with a heavy, rubber tired dump truck to find the "soft/pumping" areas and scarify them to allow them to dry quicker. If the whole site is mushy, then scarify or disc the whole site and start over with compaction after drying to about 1 to 1-1/2 percent over optimum. For this type of soil, compaction is easier and more efficient if your compaction takes place at or slightly above optimum moisture as it is drying back. If you wait until it dries to a couple of percent below optimum moisture you'll have a lot more difficulty getting compaction.

 

[amazing azza]

Thank you for the feedback Ron! How can one generally avoid the work in progress from being soaked by rain? Create a system of drainage ditches and a sump? Maybe cover area with polyethylene sheeting?

 

[BigH]

Ron - my experience is that modified would not be used for grade raising fill. Aaza - sad you couldn't get a padfoot or a pneumatic roller.

 

[Ron]

@BigH....I would agree considering the soil type. For sands and slightly silty or slightly clayey soils we would still use the Modified Proctor, even for grade fill if under buildings or pavements. For embankment, would use Standard Proctor. His original post did not specify whether Standard or Modified, so was just trying to clarify.

@azza....Obviously can't control the weather, you just have to accommodate with procedures. Drainage ditches and pumping are the better ways to handle a larger site. Usually a perimeter drainage swale with a diaphragm pump works well.

Good luck. Wet, clayey sites are tough to work with.

 

[amazing azza]

BigH, yeah.. I tried. Sheeps foot is non-existent, not sure why, it'd be perfect for the fill most frequently used around here. Pneumatics are all owned by the government and they don't rent them out. Private asphalt layers use front/back smooth rollers. The smooth vibrating rollers are coming from highway projects which are mostly handled privately.

Ron, sigh, indeed. Past two days have been tough. Despite some drying out on the surface, underneath it is still wet in some areas, up to maybe 30cm in the worst spots. The quarry where the fill is coming from is also wet, everything they send is wet. I could reject it all, but then I'd have no soil (I'll tell you guys some tales about procuring fill some other time, it's a mess). We're spreading it as thin as we can, but just as you guys said, the smooth roller is not compacting it very well. Changed the fill to one containing more gravel and sand, but it is still too clayey and too wet. All hope is that the weather stays good and this thing dries as we lay it.

I was originally targeting 95% modified, but after some preliminary measurements it does look very tough to reach indeed. Getting 85-ish % in bad spots, 90-ish % in better spots. I will re-build the proctor curve as a regular proctor using the new gravelly soil and set the new target at 95% regular proctor.

 

[1503-44]

"Mates - I think to remember what country we are looking at"

I've been detained for 24h just for having a map.

 

[Ron]

1503-44...elaborate please

 

[1503-44]

OK Ron, You asked. BigH's comment triggered an ancient memory. Starting up a 500 mile long pipeline through the Eastern Cordillera, along the border of Colombia and Venezuela in the late 80s narco-ELN territory. Extremely rough terrain with 0-5410m highest elevation. "Roads" were paved with a collection of boulders. Low swamp area roads were put in with 1m lifts. It was the Colombian Army's bad boy post region, the "Eastern Front" of South America. If we had a problem, we didn't want anybody's help, ELN's, the Army's, Dept Security DAS, or local police. The ELN blew up our pipeline and microwave towers at least once a week. We reverted to walki-talki control. Anyway after a helicopter split rotor, forced landing incident, I figured it would be good to have some kind of a minimal map of the region, so I'd know which direction to run if I had to. I started sketching one up. Bad idea. A cop at a check point decided he'd search my briefcase, found the walki-talki, the map and $500 in small bill local currency, the largest bill denomination in the country was =$10, so that wad could choak a horse, and told me I would have to talk to the lieutenant, so he took me into the village. The lieutenant wasn't posted there. He was in a town about 50miles away, so I had to stay at the police station until he could arrive the next day. They considered maps as military weapons of the AK47 level or higher. I can only imagine what would have happened if I had some kind of nuclear device on me at the time. I was temporarly deported just for not having received my work permit before the company flew us out there. Just a diving watch generated far too much attention as it was. Ever since that post I've always been overly conscious of trying to do everything with the absolute minimal amount of equipment, in a design, for construction, maintenance, well, for everything, especially with equiipment that has a lot of tech, or would otherwise be unfamiliar to LIPs, or thought of as a military weapon if they found it in my briefcase. In some parts of Saudi Arabia, an umbrella looks like a weapon. In eastern Turkey, everything is a weapon.

 

[BigH]

Thanks 1503-44 for your experience. I never had to work in an area like that but we had military accompany us when we traveled in Laos - of course, they carried. The MAG boys (Mine Advisory Group - all former British troopers never carried). We did have a few incidents - in one town on the contract 7 were killed and 13 houses burned by "guerrillas". Lots of military artillery snaked its way up into the region over the next few days.

 

[cvg]

travelled in choppers and trucks with armor plating in New Guinea. we were told to keep our heads down and don't look out the window because the snipers aim at the windows.