A bit of cohesion in the soil, some wall jogs, and less than 8 ft backfill height works in many cases. But when the temperature drops 30 Deg., or you backfill with soft cohesive soils or you have no wall jogs, then the stem wall will crack. It is a chance many spec. builders take...
See attached.
http://www.soilstructure.com/http://files.engineering.com/getfile.aspx?folder=05b02a6e-f018-4534-b452-d5e3cca654c8&file=Cantilever_Pile_in_CLAY.jpg
In the past, we have recommended crushable material between the retaining wall and the pool. This way, when the wall deflects, it doesn't push on the pool.
http://www.soilstructure.com/
If we are using the Net earth pressure method distribution on a cantilever pile, approx. 0.7H distance below base of excavation is the point of zero deflection. At this this point, the Passive resistance zone ends and the triangular net earth pressure jogs back to the Active zone. Therefore, we...
The first equation looks good to me. As far as reality, there is a lot of approximations to Ka, Ko and Kp. As you go down the wall height, friction angle can change. Also you go along the wall length, soils parameters can also change.
http://www.soilstructure.com/
This is friendly competition on how to calculate the at rest earth pressure coefficient for a given wall/soil scenario. Details are shown on the link below. Ends in couple of weeks.
https://www.hightail.com/download/bXBaOU1Uayt0QTNSc01UQw
http://www.soilstructure.com/
Over the design life of the retaining wall, the rock face may topple or move forward increasing the backfill earth pressure. So we can't rely on the active earth pressure just caused by the gravel. Talk with the soils engineer and the geologist. Some of these rock formations have out of plane...
Near the corners it can be argued that the earth pressure is at rest. That is possible, however, cantilever retaining walls designed for active earth pressure with eccentricity in the middle third and where the allowable bearing capacities are not exceeded, can withstand the at rest earth...
In addition to wannabeSE comments, if the pier length to diameter ratio is 10 or less, we recommend full length reinforcement. For piers with L/D > 10, we suggest you perform lateral foundation analysis and determine point of zero moment and that is a reasonable place to stop the drilled pier...
In addition to soil consistency, we need to know proximity to descending slope, compressibility & allowable bearing capacity for the 10 ft or so beneath the foundation.
The wind design & seismic codes have changed drastically since the 60's and this could be the reason why you have...
There seems to be three camps on this issue. Some designers take all the upward heel pressure in to consideration, some use 40% to 70% of that value and some ignore the entire upward heel bearing pressure. Same thing on the RetWall chapters in most RC books. When we make software, we don't know...
GeoBo-
Not sure if we can close the 200% or so gap that exists between us, but I will give a last try. I did a third check using Teng's method of granular soils and came up with 630 kN-m max. moment (see attached). So it seems that 400 to 600 kN-m is what I have found and you are around 1100...
avscorreia-
I also did simple analysis to double check my earlier rsults. If you convert the round section to an equivalent square pile and assume uniform lateral spring of SAND and then rotate the pile 90 degrees so that it becomes a beam on elastic foundation problem, we get rough values...
