An Investigation on the Formation of Cracks at the Corner Turns of the Modular Block Earth Walls

The design manuals for Geosynthetic Reinforced Soil Retaining Walls include the methodology for various conditions, except the case where the wall has a curved corner turn. Lately, some problems were reportedly associated with these types of walls. One of the typical problems is cracking/separation of the modular blocks. The most common method for analysing the behaviour of reinforced soil walls is a 2-D plane-strain analysis, which is insufficient for the current problem. Therefore, in this study, a 3-D finite-element (FE) model, that is capable of modelling corner turns, has been established. The main elements of the model are modular blocks, interface elements, soil, and reinforcements. As a first step, the performance of the FE model was evaluated by comparing the stress-strain response of a laboratory-scale wall with its counterpart in the FE program. Later, a large-size modular block wall model was created and run with various input parameters. The modelling results revealed that the reinforcement stiffness and the soil modulus are effective in the separation and cracking of blocks. It is considered that the cracking of blocks is related to an excessive stress build-up. These stresses reduced when the reinforcement stiffness increased. It is foreseen that the crack occurrence is less likely to happen under reduced stress.