9.2.7 Counter berms

 

A counte rberm is used to provide weight thereby increasing the shear strength at the toe region of a slope. This is particularly useful for embankments over soft soil where the ground at the toe can move upward and form a bulge (Figure 7 & 8). By locating a counter berm where the upheaval is expected to occur, the resistance against sliding is also increased. Unless careful investigation and thorough analysis is made, there is a danger that the additional load imposed by the counter berm may increase the driving force rather than providing the added resistance against sliding and lead to failure.

 

Figure 7:  Counterberm to provide weight at toe of embankment.

 

Figure 8: Application of berm  to increase slope stability