Retaining wall / Slope stability design
Retaining wall / Slope stability design
(OP)
Can anyone give me any pointers as in the best way to go about checking the stability of an existing slope on which i am construction a 7.0m high reinforced concrete retaining wall which is retaining a highway. I have designed the wall but i am concerned about the concentration on load at the top of the slope which has a gradient of 1:2





RE: Retaining wall / Slope stability design
hope this helps
Andy Machon
RE: Retaining wall / Slope stability design
RE: Retaining wall / Slope stability design
Some jurisdictions will require a global stability analyses before issuing a permit for construction, and may even require that a geotechnical report include those analyses for general site development. Assigning shear strengh parameters, friction angle, cohesion, and unit weight of soil, should be carefully considered before performing the analyses. Too conservative and things won't work on paper that might be just fine in the real world. On the other hand, aggresive shear strength values need to be substantiated with laboratory testing.
Whoever is ultimately responsible for global stability should be a geotechnical engineer or have experience in that field, and should be fully knowledgeable of the local geologic conditions. It is also a good idea to get some peer review from other engineers before making a final jugdement regarding global stability. Check around. Someone who knows your area will know what works and what doesn't, technically, economically and politically.
RE: Retaining wall / Slope stability design
I'm thinking of using a geotextile sheeting to build up the slope behind the wall in stages and improve the angle of repose and hence reduce the pressure on the wall. Do you think this will be of any benefit
Kieran
BEng(hons),CEng, M.I.Struct.E, M.I.E.I.
RE: Retaining wall / Slope stability design
Consider that global stability generally refers to what is going on behind or beneath the wall, so reinforcing the top might not provide the solution that is wanted. If the wall is also reinforced with geogrid, geotextile, steel strips, etc. then the whole system will work together and the soil reinforcement at the lower part of the wall can enhance the global stability of the system by providing strength where it is most beneficial. Putting reinforcement at the top might not keep the soil from under the wall from sliding out.
Have you considered a mecanically stabilized earth (MSE) wall? That could help with global stability. If that is not feasible, i.e. reinforcement lengths require excavation too close to existing road or adjoining property, then some sort of foundation improvement below the proposed wall might be in order.