Mechanically Stabilized Earth (MSE) Design
REA Wall performs the MSE design by any of several published design methods:
•NCMA
•AASHTO Simplified (ASD 2002)
•AASHTO LRFD
•Canadian Standard
Gravity Wall Design
•NCMA
Single depth design (multi-depth designs are done using the AASHTO methods)
•AASHTO Simplified (ASD 2002)
•AASHTO LRFD
•Canadian Standard
However, all the calculations have the same basic form:
1. Define the geometry of the wall section
2. Define the parameters for design
omoist unit weights of the soils
ostrength parameters - angles of internal friction, cohesion
oexternal surcharge loads and forces
oseismic accelerations if applicable.
3. Calculate the forces and moments of all the geometry
After all the forces and moments have been calculated the design methods suggest how the forces are applied and how the resulting stability is determined, whether by a working stress design method (NCMA, AASHTO Simplified) or by a Load Reduction Factor Design (LRFD) (AASHTO LRFD, BS8006, Australian Method). The basic design approach is the same, regardless of the method.
This chapter illustrates how REA Wall solves for the forces and moments based on the section geometry. Later, in the sections specific to design methods the final design steps will be discussed.
