I am looking for methods, guidance, past experience with placement of fill on the submerged/upstream side of an embankment dam. Fill is just needed temporarily for a working/equipment platform. Depth of water is on order of 10 to 15 feet and need pad of height on order of 25 feet.
Given that SPT is not an exact science:
Should one apply a borehole diameter correction factor, CB (other than 1.0) when determining the N60 value, if mud-rotary methods are used?
My understanding is that it is used to account for stress relief in the larger diameter borings due to overburden...
I interpret the definition in ASCE 7 for 'service loads' to indicate that they apply solely to the serviceability state (e.g., settlement) and not the ultimate limit state (e.g., bearing capacity) in geotechnical design. Is my interpretation correct?
SERVICE LOADS: Loads imparted on a building...
How deep should a boring extend when areal fill is placed on a site of deep sand or clay?
For square and strip footings, depths of 2B and 6B would extend to isobar of 0.1q; however, for areal fill, what is prudent depth?
How are the Bousinesqq stress distributions influenced by shallow hard/dense layer like shallow rock?
Are they still applicable or do other factors need to be considered for assigning an influence factor?
Is bearing pressure the same as contact pressure?
Are these terms/concepts separated by soil structure interaction?
For example, if I have a box that is 10ft x 10ft in plan, 1-ft height fill with water, bearing pressure exerted will be 62.4 psf.
But because the ground responds uniquely, the...
I've seen statements to the effect that the long-term (effective stress) values for heavily oc clay result in a lower bearing capacity than would be achieved using undrained (total stress) parameters. Dilation and development of negative pore water pressure are mechanisms for decreased shear...
Is it reasonable to use rigidity factors? I would like to hear back from engineering community on this.
Some texts say they can be used if the site is well understood; but most engineers ignore for conservatism.
I haven't seen anything stating they should not be used.
I am curious how others are estimating settlement of very high soil/rock fills that are not conducive to DMT/PMT or similar drilling methods.
My best guess is that a plate load test, if could be made applicable based on rock size, performed on shallow lifts may be the only way to do this?
Regarding Elastic Settlements:
A lot of textbooks refer to 'elastic' settlement as 'immediate' settlement, but then throw in the caveats that it is time-independent and that no moisture change (i.e no volume change) can occur.
To me, this means it can only be an undrained condition and Eu only...
Why do geotechnical engineers often not mention slab on grade settlements, since they are often independent of the building?
Is there an acceptable level of movement for slabs (total/differential)?
What is an appropriate factor of safety for shallow foundations in uplift due to wind etc; for ASD load combinations.
I think, but could be incorrect that FS should be 1.0 since ASD reduces wind loads but have not found an appropriate reference.
At what depth are the shallow foundation bearing capacity theories valid?
Terzaghi assumed D < B; however, what is the assumption if using Meyerhoff Bearing Capacity Theory?
How is the equilibrium pore pressure determined?
Is it a measured or calculated value?https://files.engineering.com/getfile.aspx?folder=2f2c78e4-8373-4ad0-b88a-05dffba44a23&file=Pore_Pressure.PNG
Allowable Stress Design (ASD) is referenced commonly as a design method for bearing capacity failure; however it is not (that I've found) referenced to the failure modes listed below. As such, I'm curious if it applies to these as well.......or are these failure modes evaluated using Limit...
I am not overly familiar with LRFD methods for shallow foundations design.
Does this method just consider bearing capacity failure or is settlement evaluated separately?
How close can the capillary water break below a slab on grade be to the water table for optimum performance?
I'm assuming as long as the capillary water break is not overwhelmed, it would be okay.
