cantilevered retaining wall - sliding resisted by asphalt?
cantilevered retaining wall - sliding resisted by asphalt?
(OP)
Hi all,
I am working on a 6 foot cantilevered retaining wall that will have 4" of asphalt cast over the toe of the footing right up against the wall. Will the asphalt resist sliding forces?
thanks for the help
I am working on a 6 foot cantilevered retaining wall that will have 4" of asphalt cast over the toe of the footing right up against the wall. Will the asphalt resist sliding forces?
thanks for the help





RE: cantilevered retaining wall - sliding resisted by asphalt?
If you need further resistance, either use concrete or a concrete key.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: cantilevered retaining wall - sliding resisted by asphalt?
RE: cantilevered retaining wall - sliding resisted by asphalt?
RE: cantilevered retaining wall - sliding resisted by asphalt?
As above, asphalt will creep, especially in warm weather.
RE: cantilevered retaining wall - sliding resisted by asphalt?
RE: cantilevered retaining wall - sliding resisted by asphalt?
RE: cantilevered retaining wall - sliding resisted by asphalt?
RE: cantilevered retaining wall - sliding resisted by asphalt?
Typical modulus of elasticity of asphalt is 1.5GPa and Poisson's ratio ν=0.35, found from the attachment.
Assuming plane strain conditions for the asphalt and the wall, the one-dimensional compression modulus is:
D=E*(1-ν)/((1+ν)*(1-2*ν))= 2.4GPa
In addition, it is well-known that the active limiting conditions in the backfill is fully mobilized when the horizontal displacement of the wall divided by its height is approximately 1%, so horizontal displacement equal to 1%*2ft=0.02ft=0.06m=6cm is sufficient. The actual displacement will be below this value.
If you know the extent of the asphalt from the toe of the wall (the distance between the wall and the point where the asphalt ends), be it y, then you can check if the resultant force at the toe of the wall F, is lower than the quantity D*(4inch)*(6cm/y).
Here I assume that y=6m, so F<2446 KN/m.
The resultant force from the earth pressures at rest are equal to:
F=(1/2)*K0*γ*h^2=(1/2)*(1/2)*(20 KN/m^3)*(6ft)^2=20KN/m < 2446KN/m then it is ok.
There were not considered active earth pressures in order to be more conservative in the calculations. The above calculations are not rigorous but rather simplistic. They are intended to show only that the asphalt layer can resist the sliding forces of the wall, in terms of static stability.
But attention must be paid in cases that the asphalt layer is removed and re-paved, or if it gets warm (you have to check the variation of modulus of elasticity with temperature). Finally, possible erosion problems may arise uner the wall's foundation, and the result of this will be the reduction of the rotational resistance of the wall. Check the value of the equivalent soil rotational spring under the wall's footing.
Best regards,
George Papazafeiropoulos
________________________
Second Lieutenant, Hellenic Air Force
Civil Engineer (M.Sc.), Ph.D. Candidate
RE: cantilevered retaining wall - sliding resisted by asphalt?
IF YOU IGNORE CREEP.
Simple observation of asphalt on roads shows that it can suffer horizontal displacement, especially near traffic lights. Those squiggly white lines weren't painted that way.
RE: cantilevered retaining wall - sliding resisted by asphalt?