Organic polymer-based composite materials with favorable mechanical performance and functionalities are keystones to various modern industries; however, the environmental pollution stemming from their processing poses a great challenge. In this study, by finding an autonomous phase separating ability of fungal mycelium, a new material fabrication approach is introduced that leverages such biological metabolism-driven, mycelial growth-induced phase separation to bypass high-energy cost and labor-intensive synthetic methods. The resulting self-regenerative composites, featuring an entangled network structure of mycelium and assembled organic polymers, exhibit remarkable self-healing properties, being capable of reversing complete separation and restoring ≈90% of the original strength. These composites further show exceptional mechanical strength, with a high specific strength of 8.15 MPa g.cm⁻³, and low water absorption properties (≈33% after 15 days of immersion). This approach spearheads the development of state-of-the-art living composites, which directly utilize bioactive materials to “self-grow” into materials endowed with exceptional mechanical and functional properties.

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Rainfall-induced slope failures are a major category of slope failure, with incidents likely to increase with the predicted escalation of extreme rainfall events. Traditional numerical methods such as the finite element method are often restricted in their applicability to small deformation analyses. Therefore, incomplete descriptions of the failure mechanism and failure consequence may be obtained, due to the evolving deformations and progressive failure being ignored. A one-point, two-phase material point method (MPM) formulation is proposed to consider the influence of rainfall on slope failure. Due to the characteristics of MPM in capturing the large deformations, the complete failure process, from initiation to failure, of a slope subjected to rainfall infiltration is presented. The soil behaviour is described by a Mohr–Coulomb strain-softening model based on Bishop's effective stress. The two-phase analysis shows that the rainfall-affected slope is initially stable, until the soil shear strength reduces due to the reduction of suction in the slope starting from the surface, leading to a superficial failure mode, which in turn leads to a complete slope failure. Friction angle and residual cohesion are shown to play important roles in the development of the slope failure.

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The simulation of slope failures, including both failure initiation and development, has been modelled using the material point method (MPM). Numerical case studies involving various slope angles, heterogeneity and rainfall infiltration are presented. It is demonstrated that, by utilising a constitutive model which encompasses, in a simplified manner, both pre- and post-failure behaviour, the material point method is able to simulate commonly observed failure modes. This is a step towards being able to better quantify slope failure consequence and risk.

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The material point method is a finite element variant which allows the material, represented by a point-wise discretization, to move through the background mesh. This means that large deformations, such as those observed post slope failure, can be computed. By coupling this material level discretization to the spatial variability of the material generated by random fields and embedding this into a Monte Carlo framework, a new method called the Random Material Point Method (RMPM) has been developed. This method retains the advantages of the so-called random finite element method, that is, a risk based interpretation of the influence of spatial variability of the material properties, but additionally enables the effective modeling of large deformations to give a risk based interpretation of post-failure mechanisms. After a brief introduction to the RMPM methodology, the analysis of an idealized cohesion strain-softening clay slope is presented, which illustrates the influence of anisotropy of the material variability on the evolution of retrogressive slope failures. @en

The simulation of slope failures, including both failure initiation and development, has been modelled using the material point method. By utilising a constitutive model which encompasses, in a simplified manner, both pre- and post-failure behaviour, the majority of types of geotechnical slope failure can be observed in the simulations. This is a step towards being able to better quantify the consequences of slope failures and thereby to a better quantification of risk. Numerical case studies involving various slope angles, heterogeneity and rainfall induced slope failures are presented to demonstrate the ability of the method to simulate commonly observed failure modes.@en

The material point method (MPM) has the potential to simulate the onset, the full evolution and the final condition of a slope failure. It is a variant of the finite element method (FEM), where the material is able to move through the mesh, thereby solving one of the major problems in FEM of mesh tangling. The post-peak material behaviour is shown here to be of importance to characterise the
failure, with an exploratory sensitivity analysis being presented highlighting the differences in the simulations. Realistic failure modes can be observed.@en

Retrogressive and progressive slope failures are a dynamic process, in the sense that they involve a progressively changing scenario. This paper uses the contemporary material point method (MPM), to provide a view of how such failures develop. Two main scenarios are presented: (a) a relatively small slope, which, when subjected to an initial failure, is steepened, leading to the initiation of further failures retrogressing backwards; and (b) a long slope, where an initial perturbation (e.g. an excavation) triggers a series of failures that can retrogressively move up-slope.

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Rainfall-induced slope failures are a major cause of slope failure, with incidents likely to increase with the predicted escalation of extreme rainfall events. Traditional numerical methods such as the Finite Element Method (FEM) are often restricted in their applicability to small deformation analyses. Therefore, an incomplete description of the failure mechanism is given, in which the failure consequences, or evolving deformations and progressive failures, are ignored. A one-point, two-phase Material Point Method (MPM) formulation is proposed to consider the influence of rainfall on slope failure. Due to the characteristics of MPM in capturing the large deformations, a complete failure process, from initiation to failure, of a slope subjected to rainfall infiltration is presented. The soil behaviour is described by a Mohr– Coulomb strain softening model based on Bishop’s stress. A retrogressive failure mode with an initial shallow instability is observed during the slope failure. In contrast with a comparative total stress analysis, i.e. without consideration of pore pressures, the two-phase analysis shows that the rainfall-affected slope is initially stable, until the suction stresses are reduced leading to a superficial failure mode, which in turn leads to a complete slope failure. @en

The random material point method (RMPM), which combines random field theory and the material point method (MPM), is proposed. It differs from the random finite-element method (RFEM), by assigning random field (cell) values to material points that are free to move relative to the computational grid rather than to Gauss points in a conventional finite-element mesh. The importance of considering the effects of both large deformations and the spatial variability of soil strength properties in slope stability analyses is highlighted, by comparing RMPM solutions with RFEM and deterministic MPM solutions for an idealised strain-softening clay slope characterised by a spatially varying undrained shear strength. The risks posed by potential slides are quantified by the extent of retrogressive failure – that is, due to the tendency for secondary failures to be triggered by the removal of support from the remaining soil mass caused by the initial failure. The results show that RMPM provides a much wider range of solutions, in general increasing the volume of material in the failure compared with the RFEM solutions, which are usually limited to the initial slide. Moreover, the anisotropic nature of soil heterogeneity is shown to have a significant influence on the nature and extent of failure@en