Seismic Design of Flexible Cantilevered Retaining Walls

Abstract

In this paper, the seismic behavior of embedded cantilevered retaining walls in a coarse-grained soil is studied with a number of numerical analyses, using a nonlinear hysteretic model coupled with a Mohr-Coulomb failure criterion. Two different seismic inputs are used, consisting of acceleration time histories recorded at rock outcrops in Italy. The numerical analyses are aimed to investigate the dynamic behavior of this class of retaining walls, and to interpret this behavior with a pseudostatic approach, in order to provide guidance for design. The role of the wall stiffness on the dynamic response of the system is investigated first. Then, the seismic performance of the retaining walls under severe seismic loading is investigated, exploring the possibility of designing the system in such a way that during the earthquake the strengths of both the soil and the retaining walls are mobilized. In this way, an economic design criterion may be developed, that relies on the ductility of the system, as it is customary in the seismic design of structures

Stability of Earth Retention System in Dry Cohesionless Soil Under Static and Seismic Condition

“…A typical cross-section of the excavation is shown in Figure 3. The soil properties namely, dry density, friction angle and initial shear modulus are taken from [8]. The coefficient of lateral earth pressure at rest (K 0 ) is taken as 0.426 (for φ equal to 35 o ).…”

“…The wall friction angle (δ) and the Poisson's ratio (μ) of soil are taken as 20 o and 0.30 respectively. The small strain shear modulus (G 0 ) and mean effective stress (p′) are related as [8] …”

“…However, very few studies have been done for analyzing the behavior of such type of excavation under seismic condition. Numerical analysis of embedded cantilever retaining walls in dry coarse-grained soil under seismic condition using Tolmezzo time acceleration history data has been analyzed in FLAC [8]. A number of studies has been done on other types of retaining walls such as gravity, cantilevered, anchored walls or mechanically stabilized earth retaining walls under seismic condition ( [9], [10], [11], [12], [13], [14]).…”

“…The effect of Tolmezzo earthquake which occurred in Italy is considered in the present study. The acceleration time history data has been taken from [8]. This history data is applied at the base of the model.…”

A two-rigid block model for sliding gravity retaining walls

“…The idea is that of defining a critical value of the acceleration, a c (¼ k c g), for an active type of soil-wall failure mechanism, and then computing the displacements of the wall due to a base acceleration a (¼k h g), by direct double integration of the relative acceleration (a À a c ). The underlying assumption is that, when the wall moves relative to its base, the absolute acceleration of the wall remains constant and equal to its critical value [4]. Only a few authors [33,23,31] apply a corrective factor to the relative acceleration, emerging from direct consideration of the equation of motion of the soil-wall system.…”