Deformation and failure modes of drystone retaining walls

Abstract

In this paper, the factors controlling the deformation of drystone retaining walls are investigated by means of discrete element analyses. It is shown that toppling failure of unweathered drystone retaining walls is likely to occur in a brittle manner, with wall crest deflections not exceeding 1% of the backfill height until the factor of safety (based on soil strength) falls below 1·05. A compressible sub-base and weathering of the blocks will both tend to reduce the backfill height at failure to below that indicated by a limit equilibrium analysis. Bulging failure is more likely to be associated with a deterioration in block joint stiffness due to weathering than a compressible sub-base, although the latter will decrease the reduction in joint stiffness needed to cause bulging failure. Bulging is much less brittle than toppling, and the proximity to failure of bulging walls could in some circumstances be assessed on the basis of the size of the bulge.

3D failure of a scale-down dry stone retaining wall: A DEM modelling

“…Consequently, 3DEC allows geotechnical or construction problems to be solved by a mixed discrete-continuum approach [13]. In the past, this code was used to get more insight into the behavior of plane DSRWs where pathologies observed on site and the behavior of specific DSRWs toward failure could have been reproduced [7,9,10,14].…”

“…Harkness [7] modeled Burgoyne's field experiments using UDEC code (DEM, ITASCA code) [8], confirming the qualitative results Burgoyne obtained. Also based on Burgoyne's tests, Powrie et al [9] and later Claxton et al [10], performed numerical simulations, studying the influence of the mechanical properties and geometry of blocks on the wall stability. Recently, Oetomo et al [11] modeled the behavior of slope DSRWs by two methods.…”

Assessing the two-dimensional behaviour of drystone retaining walls by full-scale experiments and yield design simulation

“…This ultimate loading height, h þ s , is the minimum value of h s over all virtual velocity fields, which verifies equation (2) ( 1, 0, 0) Ϫ Full-scale field trials on drystone retaining walls Aim of experiments. The experimental programmes undertaken in 2002-2003(Villemus, 2004) and 2007-2008(Colas, 2009) at the ENTPE aimed to provide a better understanding of drystone two-dimensional behaviour by way of calibration and validation simulations. Full-scale trials are essential to take into account the strong heterogeneity of drystone masonry, as well as the specificities of soil-structure interaction.…”

“…Second, when dealing with drystone retaining structures, it is necessary to take into account the backfill and the soil-structure interaction, which means that soil mechanics must be accounted for. Simulations on drystone constructions fall into two categories: (a) macro-mechanical approaches, where the masonry is treated as a continuous medium (Arya & Gupta, 1983;Cooper, 1986;Villemus et al, 2007;Mundell et al, 2009); and (b) micro-mechanical approaches (finite-or distinct-element methods), where the wall is represented as a combination of blocks (Dickens & Walker, 1996;Harkness et al, 2000;Powrie et al, 2002;Zhang et al, 2004;Claxton et al, 2005). In addition, only a few recent experiments have been undertaken on drystone retaining structures (Villemus et al, 2007;Mundell et al, 2010).…”

Modeling the 2D behavior of dry‐stone retaining walls by a fully discrete element method

“…Indeed, the user has the possibility to glue rigid circular bodies together generating more complex bodies. The approach considered in this work is different from previous numerical studies [9,10,19,20] which coupled a discrete method for blocks and a continuum model for backfill. At each time-step, the calculation runs in alternate between contact-force law and law of motion.…”