Stability analysis of 3D geosynthetic–reinforced earth structures composed of nonhomogeneous cohesive backfills

• Published in: Soil dynamics and earthquake engineering (1984) 2019-11, Vol.126, p.105768, Article 105768
• Main Authors: Xu, Jingshu, Du, Xiuli, Yang, Xiaoli
• Format: Article
• Language: English
• Subjects: Cohesion; Cohesion nonhomogeneity; Dimensional stability; Earth reinforcement; Earth structures; Energy balance; Energy dissipation; Geosynthetic-reinforced earth structure; Geosynthetics; Internal energy; Limit analysis; Mathematical analysis; Parametric analysis; Pore water; Pore water pressure; Preliminary designs; Seismic activity; Seismic engineering; Seismic response; Seismic stability; Soil analysis; Soils; Stability analysis; Stability charts; Unfactored reinforcement strength; Water pressure
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2019.105768

Soils are assumed to be homogeneous in most designs of geosynthetic-reinforced earth structures (GRESs), thus ignoring the influences of the possible cohesion and cohesion nonhomogeneity of backfills. However, the actual stability of GRESs is directly influenced by the presence of cohesion and cohesion nonhomogeneity of backfills along with the three-dimensional (3D) character of GRESs. In the present study, a chart-based stability analysis of a 3D GRES composed of nonhomogeneous cohesive backfills subjected to the seismic excitation/pore water pressure is conducted by means of the limit analysis method. Work rates by seismic forces and pore water pressure are calculated based on the pseudo-static method and the pore water pressure coefficient, respectively; thereafter the energy balance equation is derived by equating the external work rates of the soil weight and seismic forces/pore water pressure to the sum of the work rate of the geosynthetics and internal energy dissipation caused by soil cohesion. The analytical expression of the required unfactored reinforcement strength is derived and the optimized solutions are consequently captured. A comparison is drawn to verify the present study and a parametric analysis is conducted thereafter to investigate the effects of the 3D character, cohesion nonhomogeneity, seismic excitation and pore water pressure on the stability of GRESs. Finally, a set of stability charts considering the 3D effects, cohesion nonhomogeneity, seismic force and pore water pressure on long-term stability is proposed for preliminary design purposes. •An advanced 3D failure mechanism is adopted to investigate the stability of GRESs in nonhomogeneous cohesive backfills.•Three different categories of reinforcement patterns are considered.•Analytical expressions of the required unfactored reinforcement strength of 3D GRESs are derived.•The effects of factors such as cohesion nonhomogeneity on stability of GRESs are investigated.•A set of stability charts is proposed for preliminary design purposes.