PSEUDO - STATIC ANALYSIS OF NAILED SOIL SLOPES

Abstract

Failure of soil slopes is observed under static loading, dynamic loading and rapid drawdown conditions. In the first part of present study, soil nails are installed at an inclination of 10 ,15  and 30 with the horizontal and subjected to tensile stresses. Nailing is carried out in homogeneous soil slope subjected to pseudo-static loading and assuming a planar failure surface passing through the toe of the slope. The global factor of safety is calculated analytically considering both resisting forces and driving forces. The influence of various factors like inclination angle of the nails with the horizontal, combinations of horizontal and vertical seismic acceleration coefficients along with soil friction angle on the factor of safety is studied. It is observed that factor of safety reduces with increase in seismic acceleration coefficients and inclinations angle of soil nails. Design charts obtained using the proposed method can be used for analysis of reinforced soil slopes under seismic conditions. In the second part of present study for logspiral failure surface the factor of safety variation is carried out by varying parameters like surcharge (q), apparent coefficient of friction (f), combinations of horizontal and vertical seismic acceleration coefficients (kh and kv). Moment equilibrium is used to calculate factor of safety for logspiral failure surface.