Aesthetically and practically a timber crib wall may be a solution but may cost slightly more - as your talking of sidewalks I assume your not in UK so I'm afrad I can't help on price.
I did my MSc at Bolton Institute in the UK and we used ANSYS for settlement and Flow Net type problems. I don't use it now but they possibly still teach it. The website address is www.bolton.ac.uk and the head of civil engineering courses is at sam1@bolton.ac.uk.
The guy teaching the ANSYS...
I am looking at a failing wall with a backfill with a phi value of 30 degrees and no cohesion.
One solution is to excavate the backfill and replace it with material with a higher phi value and/ or cohesion. One material being considered is dry mix concrete or possibly no fines concrete.
Has...
Condider a circular failure centred on the outside edge of the foundation. In order to fail the disturbing forces have to overcome frictional forces along the line of failure, which are influenced by normal pressures across the failure surface, and would also have to lift up the wedge of soil...
Purcupine walling is a proprietary block walling system with longitudinal ridges on the top which interlock with grooves on the base of the next block. When viewed end on the ridges make it look like a porcupine or hedgehog (with a stretch of the imagination) also good fun to leave a phone...
Stroud and Butler (1975) in The Engineering Beahaviour of Glacial Materials - -The Midlands Soil Mechanics and Foundation Engineering Society - give correlations between SPT N and Cu and Mv for glacial tills, which are commonly used in the UK.
A slope of 1 in 1 (45 degrees) sounds pretty steep for a slope in silty sands especially with groundwater present and may be borderline stable. Is the slope mainly bedrock and will the retaining walls involved supporting natural ground or fill?
As the wall is relatively low also try proprietary systems such as timber or concrete crib walling or gabions or maybe porcupine walling for lower sections? Design is simple, from tables etc or can be designed by the supplier.