Geosynthetic Reinforced Soil (GRS) Walls

2Lateral Earth Pressure and Rigid Earth Retaining Walls

When a significant change in grade is needed or desired in earthwork construction, one of four methods can be taken: (i) provide a stable slope, about 2:1 (horizontal:vertical) for granular soil without any concern of seepage (and about 4:1 with concern of seepage), to allow for gradual transition between the grades, (ii) construct a stable steepened slope with geosynthetic inclusion near the face of the slope to allow tighter transition between the grades, (iii) construct an earth retaining wall to allow an abrupt change in grade, and (iv) a combination of the above measures. The choice of method depends largely on the availability of space between the grades. An earth retaining structure is the method of choice when there is severe space constraint.

Earth retaining walls can be grouped into two categories: rigid retaining walls (gravity walls, cantilever concrete walls, crib walls, etc.) and flexible retaining walls (cantilever sheet pile walls, anchored sheet pile walls, etc.). Design and analysis for the former is typically based on classical earth pressure theories, while the latter is based on empirical pressure diagrams and charts. In this chapter, we shall focus our attention on rigid retaining walls. Compared to “reinforced soil walls” where the soil mass is internally stabilized by embedding tensile inclusion within the soil mass, the soil mass in “rigid retaining walls” (and “earth retaining walls” in general) ...