Monitoring elastic settlements
Monitoring elastic settlements
(OP)
I have a site where 2-3 meters of fill will be placed. The subgrade soils are unsaturated overconsolidated clays with the thickest layer of approx 3 m thick.
For monitoring settlements ,what could be the requirements? For example: what could be the max. "x" difference between 2 consecutive readings in order to stop the monitoring? Since I expect only elastic settlements to occur, I do not think that this settlement monitoring will take more than 2 weeks. Well, it will depend on how strict will be the amount "x".
For monitoring settlements ,what could be the requirements? For example: what could be the max. "x" difference between 2 consecutive readings in order to stop the monitoring? Since I expect only elastic settlements to occur, I do not think that this settlement monitoring will take more than 2 weeks. Well, it will depend on how strict will be the amount "x".





RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
HENRYZAU, BTW what does DOC stand for?
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
RE: Monitoring elastic settlements
If it's unsaturated and there connected air blebs remain, it's unlikely that permeability will influence change in void ratio. If it's near saturated (i.e., the remaining air is all in isolated blebs), then permeability will be a factor.
Do you have a well in the clay that shows no water?
Do you only have observations of a saturated sand above a clay layer and then concluded that the sand is perched on the clay (i.e., did you allow some story to prevail over reality)?
OCR of 2 is not that great!
I'd be all over the moisture contents, liquid limits, blow counts, oedometer data and I'd consider the nature of the risk.
Then again, it's just a slab on grade!
f-d
ípapß gordo ainÆt no madre flaca!
RE: Monitoring elastic settlements
I do not have a well, but based on our borings and knowledge of local geology, groundwater is at deep locations, no within the clay layer. Groundwater is within the gravelly limestone layers underneath the clay layers, about 10 meters below the interface the clay and gravel layers. There is not a soil layer above the clay layer. So, the soil profile is composed of clay soils overlying gravelly limestone soils.
Moisture contents are well below the LL. Blow counts are 7 in average. Unfortunately I do not have oedometer data for this site, but I do have oedometer data from past projects and know that our clays may have OCR between 2 and 4, perhaps more.
To minimize risks, I am thinking for settlement monitoring after fill placement and construction of slab-on-grade to begin after settlements are stabilized.