Stabilizing Piles of Soft Cohesive Slopes: A Case History


Tarek N. Salem1, Mohsen Mashhour2, Rana Hassan3

1: Prof. of soil mechanics and foundations, Zagazig University, Egypt,
2: Prof. of soil mechanics and foundations, Zagazig University, Egypt,
3: Teaching assistant, Zagazig University, Egypt,



Slope stability is one of the most important problems in geotechnical engineering because failure could cause catastrophic environmental and human disasters, in addition to large economical losses due to such failure. The purpose of this paper is to study the effect of using piles in stabilizing the embankments of Al-Salam Canal in Northern Egypt. The canal left side is a formed soft clay embankment which is mainly formed from dredging and cleaning of the bottom of the nearby Al-Manzala lake. Sudden and progressive failures took place in the left side embankment over years for many reasons. These failures are mainly due to the nature of the soft clay forming the slope in addition to the existence of gypsum and peat pockets and thin layers within the slope in many locations. Thus, it was suggested to use a row of reinforced concrete piles to stabilize the left side embankment of the canal. Analysis of the slope stabilized by piles is performed using finite element analysis. Although the slope stabilizing piles were able to stabilize the slope to some extent, increasing the number of pile rows was not effective in increasing the safety factor in return. Another slope stabilizing technique is studied herein using lime treatment. The proposed lime treatment technique was effective in stabilizing the slope more than the slope stabilizing piles, even in the zones containing the peat layer.

Keywords: Slope Stability; Piles; Soft Clay; Peat; Lime Treatment; Numerical Analysis; Slope Stabilizing Piles.

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