The studied case is the left side embankment of Al-Salam canal which was originally a
formed one. Thus, the embankment is formed of dredged soft clay, organic materials, and gypsum
pockets and even layers within the embankment slope.
Due to the soft nature of the slope and the existence of organic layers such as peat, sudden
and progressive failures took place in the left side embankment. It should be noted that the peat
layer caused most of the slope failures and the gypsum pockets even caused local failures in the
slope accompanied by water piping when the water level in occasions of the nearby Al-Manazala
lake happen to be higher than that in Al-Salam Canal.
As a part of the strategic project of developing the Sinai Peninsula, it was decided to widen
the canal width, along with improving the capacity and widen the highway in the canal left side.
The slope height and inclination angle of the canal will remain the same after the proposed canal
widening, only the canal cross-section was increased by cutting 3.0 m from the berm in each side
in order to improve the canal water flow capacity.
There is an existing highway in the canal right side, with no apparent stability problems for
being a cut slope in a relatively stiffer soil. So, the canal left side embankment of soft soil was not
stable enough to sustain such widening along with the expected highway traffic loads, Al-Ashaal
et al., (1998). Field investigations were performed to evaluate the current slope status, and