Seismic design of bilinear geosynthetic-reinforced slopes

The scenario of two tiered geosynthetic-reinforced slopes, where the upper tier is vertical and the lower tier is inclined at an angle, is termed as a bilinear geosynthetic-reinforced slope (BGRS) in this note. This note presents a pseudo-static limit equilibrium approach employing a top-down log spiral mechanism to determine the resultant reinforcement force in the lower tier required for global seismic stability. An example was presented to illustrate steps for achieving the resultant reinforcement force required for internal seismic design of reinforcement rupture and show how much the maximum reinforcement force at each layer is in line with its distribution function. The reinforcement force in the BGRS is subsequently compared with that in the equivalent geosynthetic-reinforced slope under different case. In addition, it is found that the resultant reinforcement force in the lower tier increases first and then decreases with an increase of height ratio of the upper tier to the BGRS.