AASHTO Simplified Earth Pressure
AASHTO Simplified Earth Pressure
(OP)
In working with Figure 3.11.5.6-6 in the AASHTO LRFD Bridge Design Manual, I am finding conflicting opinions on how to handle the increased embedment of 1.2D. I consulted a Geotechnical engineer who stated the 1.2D is performed to achieve a F.S.=1.5. I reviewed references stating the 1.2 factor is used to account for differences between the simplified method and the conventional method and is not a factor of safety. Those references would apply a factor of safety by reducing the passive pressure (as I would commonly do), find the point of moment equilibrium and finally increase the embedment by 20% when using the simplified method.
I would appreciate it if anyone could share their thoughts, experiences or perhaps references that reinforce either position. Thank you in advance.
I would appreciate it if anyone could share their thoughts, experiences or perhaps references that reinforce either position. Thank you in advance.






RE: AASHTO Simplified Earth Pressure
RE: AASHTO Simplified Earth Pressure
They also require that KP be reduced by 1.5 for permanent walls and 1.25 for temporary walls, which is an additional safety factor.
I hope I didn't muddy up the waters for you.
RE: AASHTO Simplified Earth Pressure
RE: AASHTO Simplified Earth Pressure