Landslides and stability of coastal cliffs of Cox's Bazar area,Bangladesh

Successive applications of two-dimensional circular slip limit equilibrium analysis of slices have been made to the three sections of the Cox's Bazar Coastal Cliff. These three sections have been found to be stable (S), quasistable (QS), and unstable (U) with factors of safety (Fs) of 1.269 ± 0.01, 1.13 ± 0.0504, and 1.01 ± 0.058, respectively. In the quasistable and unstable sections, the slopes suffered shallow slidings with slip circles parallel to the surface of slopes.The main causes of these slidings are steepness of slopes, lack of vegetation cover, erosion of toe accumulations by run-off water and waves during high tides. The influence of the slope geometry and the material's strength properties of slopes on safety factors are evaluated. The steeper cliffs reach an unstable condition faster than the more gentle cliffs as their heights change by an equal amount. Again, the high cliffs reach an unstable condition faster than the lower cliffs as slope inclinations change by an equal amount. The safety factor increases with a corresponding increase of friction angle (ø°) and vice versa.Abbreviations BK Bahar chara to Kalatali chara - KR Kalatali chara to Reju khal - RI Reju khal to Boro Inani khal - Fs Factor of Safety - S Stable - QS Quasistable (semistable) - US Unstable