Should I perform a slope stability analysis?

[geot88]

Hello guys,
I need some help on this project. I have attached the an image to understand it better.
I have this concrete structure that will support a 2-lane highway, 1-way per direction. The client asked to do the geotechnical investigation and calculate the bearing capacity of the strip footing. They didn't provide any load information.
However, I think I also need to calculate the slope stability of it. There is MH and ML from 0 to 3 meters, then SP-SM with N going from 5 to 50 the next 10 meters.

My doubt is; will the highway loads be transferred to the concrete structure, then to the footings and finally to the soil? Should I perform a slope stability analysis?

Thanks in advance, y'all

 

[oldestguy]

First off per your drawing, there is plenty of load information with that attachment for establishing what sort of investigation you need for bearing capacity.

Without a topographic map showing the overall site conditions, your question about slope stability can't be answered, yes or no.

 

[Doctormo]

To answer your question: Yes, the highway loads will be transferred to the arch and then to the footings. The US standard is to add a uniform 12 kM/m2 live load surcharge on the roadways. The actual design of the arch structures should be able to provide you with the loads at the foundation level per the analysis method used. (kN/m or kN/m2 for a footing width)

A slope stability analysis would not have much to do with the archs and foundation loads but would look at the roadways embankment slopes above and adjacent to the structure which would probably not work out well based on the 1:1 side slope shown in your figure. 1:1 fill slopes may be common where you work but they never satisfy a slope stability analysis without utilizing cohesion which is a subject onto itself.

My guess would be that the MH and ML foundation soils may not provide sufficient support, especially if wet. This would be determined from your soil borings, water table elevation, etc. There also may be erosion and scour concerns that require the footings to be deeper than necessary from a structural standpoint.