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, Lmin, for external seismic stability of vertical GRS walls by pseudo-static limit equilibrium method. Then, Lmin can be calculated to resist sliding, eccentricity, and bearing capacity failure modes. The parameters considered include both horizontal and vertical seismic coefficients (kh and kv), surcharge load (q), wall height (H) and the properties of retained backfill, GRS, and foundation soil. Results show that Lmin against sliding failure mode, Lmin,S, increases more quickly than that against the other two failure modes with the increase in kh, q, or unit weight of retained backfill, γb, while Lmin,S decreases more quickly than that against the other two failure modes with increase in friction angle of retained backfill, ϕb, or unit weight of GRS, γr. For the different failure modes, the effect of kv on Lmin is not identical with the change of kh, and in addition, Lmin/H will tend to remain unchanged with the increase in H. In general, Lmin against bearing capacity failure mode, Lmin,BC, is larger than Lmin against the other two failure modes. However, Lmin,BC will be less than Lmin against eccentricity failure mode, Lmin,E, for kh exceeding 0.35, or friction angle of foundation soil, ϕf, exceeding 37°, and Lmin,BC will also be less than Lmin,S for friction angle of GRS, ϕr, being no more than 26°.