Effect of slope geometry on stability of slope in Almaty

Abstract

Landslides bring destruction to buildings, and nearby located structures and mostly occur in rural areas. Such hazard commonly takes place in mountainous areas in Central Asia. Kazakhstan region has highly vulnerable areas to rainfall-induced landslides in South-Eastern parts due to presence of many mountains. The purpose of the research is to demonstrate the effect of slope geometry on slope stabilityunder heavy rainfall in Almaty, Kazakhstan. Transient seepage analyses were conducted using Seep/W while limit equilibrium slope stability analyses were performed using Slope/W. 15 sets of numerical analyses were carried out on different slope angle and slope height incorporating the soil-water characteristic curve and unsaturated permeability and unsaturated shear strength of soil from Almaty. According to the obtained simulation results in GeoStudio software for seepage analysis, the pore-water pressure is increased almost for 80 kPa at the mid slope of each simulation. The change of FoS for the gentlest slope with 27 degrees slope angle is the lowest for 10 m slope height and the highest for 30 m slope height, whereas the change of FoS for slope with 45 degrees of slope angle (9%) is almost the same for all slope height.

Effect of groundwater level on slopes to construct the SWCC curve for unsaturated soil

“…The stability of a slope is quantitatively evaluated using a stability factor, denoted as Fs. This factor represents the ratio between the total moment of resisting forces, Mg (including cohesion and friction of the soil), and the total moment of driving forces, Mt (consisting of external loads, weight of the sliding block, water pressure, seepage pressure, and other relevant factors) [13]: …………….. (1) Where: [Fs] is permissible anti-sliding stability factor, dependent on the rank of the construction, as specified by regulations.…”