External seismic stability of vertical geosynthetic-reinforced soil walls using pseudo-static method: Fid-Bau Portal

External seismic stability of vertical geosynthetic-reinforced soil walls using pseudo-static method

Ruan, Xiaobo / Sun, Shulin

Abstract Analysis of external stability of vertical geosynthetic-reinforced soil (GRS) walls is very important in the seismic prone zone. The scope of this paper is to obtain required minimum reinforcement length, L min, for external seismic stability of vertical GRS walls by pseudo-static limit equilibrium method. Then, L min can be calculated to resist sliding, eccentricity, and bearing capacity failure modes. The parameters considered include both horizontal and vertical seismic coefficients (k h and k v ), surcharge load (q), wall height (H) and the properties of retained backfill, GRS, and foundation soil. Results show that L min against sliding failure mode, L min,S , increases more quickly than that against the other two failure modes with the increase in k h , q, or unit weight of retained backfill, γ b , while L min,S decreases more quickly than that against the other two failure modes with increase in friction angle of retained backfill, ϕ b , or unit weight of GRS, γ r . For the different failure modes, the effect of k v on L min is not identical with the change of k h , and in addition, L min/H will tend to remain unchanged with the increase in H. In general, L min against bearing capacity failure mode, L min,BC, is larger than L min against the other two failure modes. However, L min,BC will be less than L min against eccentricity failure mode, L min,E , for k h exceeding 0.35, or friction angle of foundation soil, ϕ f , exceeding 37°, and L min,BC will also be less than L min,S for friction angle of GRS, ϕ r , being no more than 26°.