Soil cracking modelling using the mesh-free SPH method

The presence of desiccation cracks in soils can significantly alter their mechanical and hydrological properties. In many circumstances, desiccation cracking in soils can cause significant damage to earthen or soil supported structures. For example, desiccation cracks can act as the preference path way for water flow, which can facilitate seepage flow causing internal erosion inside earth structures. Desiccation cracks can also trigger slope failures and landslides. Therefore, developing a computational procedure to predict desiccation cracking behaviour in soils is vital for dealing with key issues relevant to a range of applications in geotechnical and geo-environment engineering. In this paper, the smoothed particle hydrodynamics (SPH) method will be extended for the first time to simulate shrinkage-induced soil cracking. The main objective of this work is to examine the performance of the proposed numerical approach in simulating the strong discontinuity in material behaviour and to learn about the crack formation in soils, looking at the effects of soil thickness on the cracking patterns. Results show that the SPH is a promising numerical approach for simulating crack formation in soils

💡 Research Summary

The paper addresses the critical need for reliable numerical prediction of desiccation‑induced cracking in soils, a phenomenon that can dramatically alter mechanical strength, hydraulic conductivity, and overall stability of earthen structures. Traditional finite‑element (FEM) and discrete‑element (DEM) approaches struggle with large deformations, mesh distortion, and explicit tracking of fracture surfaces, which limits their applicability to realistic shrinkage problems. To overcome these limitations, the authors extend the mesh‑free Smoothed Particle Hydrodynamics (SPH) method for the first time to simulate shrinkage‑driven crack formation in soils.

The methodological framework begins with a concise review of SPH fundamentals. In SPH, the continuum is represented by a set of particles that carry mass, momentum, and internal variables; field quantities are approximated through kernel‑weighted sums over neighboring particles. This eliminates the need for a fixed mesh and naturally accommodates large strains and discontinuities. The authors embed a nonlinear elastoplastic constitutive model suitable for cohesive soils, combining an isotropic elastic backbone with a J2‑type plastic flow rule and a Mohr‑Coulomb shear failure criterion. To capture desiccation, an isotropic shrinkage stress tensor is introduced, which acts uniformly on all particles and mimics the tensile stresses generated by moisture loss.

A key innovation is the damage‑based fracture model. Each particle carries a scalar damage variable, (d\in