ABSTRACT
Shake table tests on two-tiered metal-strip MSE walls showed that the prevention of slip surface development in the lower half of the wall, improving seismic stability by increasing failure threshold acceleration, and mitigating acceleration amplification were the main advantages of using a two-tiered configuration in constructing MSE walls. This was also found that the use of an insufficient offset distance not only eliminated the advantage of the tiered configuration for reducing wall deformations, but also increased the wall crest displacement. Hence, 0.22 H was found to be as the minimum offset distance required when constructing MSE walls in a two-tiered configuration.
Acknowledgments
The authors wish to express their sincere thanks to Prof. R.J. Bathurst of the GeoEngineering Centre at Queen’s-RMC and Prof. A. Ghalandarzadeh at Tehran University for their kind assistance throughout this research effort.
Disclosure Statement
No potential conflict of interest was reported by the author(s).
Data Availability Statement
Some or all data, models, or code generated or used during the study are available from the corresponding author by request.
Notation
Basic SI units are shown in parentheses
Am acceleration amplification factor (dimensionless)
ay yielding acceleration (m/s2)
B backfill width (m)
Cf coefficient of fundamental period (dimensionless)
D offset distance (m)
DPenormalized permanent displacement (dimensionless)
Dr relative density (dimensionless)
DRrnormalized reversible displacement (dimensionless)
Dmax normalized maximum wall deflection (dimensionless)
Dn normalized seismic displacement (dimensionless)
D50medium grain size (mm)
E elastic modulus of soil (MPa)
Esttensile stiffness of reinforcement (GPa)
f frequency (Hz)
ff fundamental frequency (Hz)
g acceleration due to gravity (m/s2)
Gs specific gravity (dimensionless)
H total wall height (m)
H1height of the lower tier (m)
H2height of the upper tier (m)
kh horizontal seismic coefficient (dimensionless)
L Reinforcement length (m)
L1Length of reinforcements located in the lower tier (m)
L2Length of reinforcements located in the upper tier (m)
M Flexural resistance per unit width (kN.m/m)
N scale factor between prototype and physical model (dimensionless)
SH&SV Horizontal and vertical spacing between reinforcement (m)
Sglobalglobal reinforcement stiffness of the wall (kN/m2)
Tf fundamental period (second)
Tmax maximum mobilized tensile force (N/m)
Tn normalized reinforcement force (dimensionless)
Vs shear wave velocity (m/s)
εs cumulative shear strain (dimensionless)
γsoil unit weight (kN/m3)
∆x(max)maximum wall deflection (m)
∆xN(max)maximum normalized wall deflection (dimensionless)
αgoverning parameter the similitude rules (dimensionless)
σv confining pressure (kPa)
φp peak internal friction angle (degree)
φp-p post-peak internal friction angle (degree)