elastic settlement
elastic settlement
(OP)
I'm designing a shallow foundation of 3X6m and with 900tons I have SPT and CPT values of the layered soil. The soil's first 0.3 m is sandy to silty sand, 1.7m clay, 0.2m silty clay to clay, 1m clay, o.5m silty clay to clay. There is no water table. Where do you think I should place the foundation, and with what formula should I calculate the elastic settlement, and to what depth )depth of influence? Thank you all, any advice will be helpfull.





RE: elastic settlement
RE: elastic settlement
RE: elastic settlement
Since the surveys rule out the presence of water (it is implied for a certain depth below the foundation) how do we deal with consolidation?
If we get samples they'll be at least partially saturated in the lab, which is not the natural condition (assuming again that the groundwater level is well below the foundation depth).
In such a case the consolidation moduli meausred in the lab would be overconservative.
Do you guys ever reason in such terms? Do you evaluate the saturation ratio to estimate wheter the soil will behave more as a saturated or unsaturated material?
RE: elastic settlement
RE: elastic settlement
Or dilatometer tests where the pressuremeter is not widely used. In some instances it is observed that the edometric moduli calculated from the dilatometer surveys are significantly larger than the edometric moduli from lab tests. An explanation may be that, in unsaturated soils, the edometric modulus is closely related to the elastic modulus since consolidation phenomena do NOT occur. Unfortunately, I couldn't find any comments on that in the literature, even professor Marchetti, the inventor of the dilatometer, says nothing about these observations.
I wonder if it is the same with the pressuremeter (frequent disagreement between lab tests and pressumeter edometric moduli in similar soils).
RE: elastic settlement
RE: elastic settlement
RE: elastic settlement
For unsaturated clay that's fluvial in nature and when the natural moisture content is well below the liquid limit, I'd just use elastic theory and move on. . . A DPT or pressure meter would be a good tool for sure.
Disturbed clays that dry out can show a dry strength that's misleading. So, fills can be a problem if there is no compaction control and n-values are obtained in the summer. Especially for soils in the upper 5 ft or so.
Please recognize that your data only extends to 3.7 m and you are designing a footing that's 3 x 6 m. I'd think this is not sufficient.
f-d
¡papá gordo ain’t no madre flaca!
RE: elastic settlement
RE: elastic settlement
RE: elastic settlement