Advanced analysis of masonry retaining walls using mixed discrete–continuum approach

A study was carried out into extending the use of the mixed discrete–continuum approach for advanced numerical analysis of masonry retaining walls. This included incorporation of soil plasticity, irregular wall morphology and application to a real-life scenario to identify the causes of observed damage patterns. Backfill soil was simulated by way of a deformable continuous medium, while masonry units were represented as polyhedral rigid blocks interacting with each other. Upon validation, the approach was used to simulate the behaviour of an historical masonry retaining wall suffering from severe cracks, large deflections and partial collapse due to material degradation and differential soil settlement. To understand the progressive response of the structure better, a parametric analysis was performed on the tensile strength of masonry when the system was subjected to differential settlement. Further static analyses were performed to assess the capacity of the wall under uniform surcharge pressure. The results demonstrated the sensitivity of the macro behaviour of the wall to the tension capacity of masonry. The study also showed that the proposed modelling approach can provide useful performance information on existing retaining walls that are vulnerable, and that such validated numerical models should be used to determine any interventions and repairs.