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The research on the concrete structure built with self-healing materials brings inspiration to increase the safety and sustainability of underground structures in the whole life cycle. The utilization of microencapsulated healing agents in self-healing concrete has demonstrated efficacy in the repair of microcracks within concrete structures. Nevertheless, there exists a dearth of effective methodologies for assessing the impact of microcapsule parameters on the mechanical properties of self-healing concrete. This study introduces an innovative three-dimensional micromechanical model that can be utilized to analyze the micromechanical response of microencapsulated self-healing concrete under tensile loading conditions. The 3D micromechanical model is accomplished through the utilization of the elastic secant compliance tensor. Subsequently, a comprehensive examination is undertaken to analyze the progression of damage-healing in self-healing concrete incorporating microcapsules. Finally, a parametric investigation is conducted to elucidate the impact of the micro-parameters on the mechanical behavior of self-healing concrete. The present discovery holds significant implications for the development of microencapsulated self-healing concrete for underground structures, particularly in terms of establishing appropriate parameters. [ABSTRACT FROM AUTHOR]

The computational cost of discrete element modelling is high owing to the limitations of particle size and contact in fibre modelling. This paper proposes an optimised discrete element method (DEM) for a hybrid model of soil and fibres based on the fibre influence range. First, a relative velocity state function is established based on the relative motion state between the fibres and soil particles under undrained cyclic loading. Subsequently, the influence range of the fibres is determined using the relative velocity function based on the first few cycles of the undrained cyclic loading numerical tests. Cluster and clump models of the fibre are then generated based on the influence range of the fibre. Finally, a symmetrical shape of the optimised model is developed by extracting the distribution length of the edge curve of the influence range along the vertical direction of the axis. In this study, the proposed optimised DEM was validated through a series of undrained cyclic loading numerical tests on fibre-reinforced soil. The results of the optimised model were highly consistent with those of the traditional model, and the computational time was significantly reduced. The cyclic loading timing for determining the range of influence of the fibre was analysed. The optimised model based on the influence range of the 15th cycles not only restored almost the same results but also saved the calculation cost by nearly eight times. The optimised model established based on the influence range after the 15th cycles had a slight influence on the results. In addition, the applicability of the optimised model is discussed. This paper provides new insights into the establishment of a hybrid model of soil and fibres. [ABSTRACT FROM AUTHOR]

In this study, we propose a multivariate joint distribution model for marine soft soil using D-vine copula function. The model is based on detailed investigation data from a tunnel constructed in marine soft soil. The variation patterns of the mechanical and physical parameters of quaternary marine–land interaction sedimentary soft soil layers were analysed. First, a comprehensive database of marine soft soils was established on the basis of detailed field investigation data. The variability and correlations among the physical and mechanical performance indices of the soft soil were then analysed. Subsequently, optimal marginal functions for nine soil parameters were proposed on the basis of the fitting characteristics of the physical and mechanical performance parameters of the soft soil. Finally, 15 copula functions were used to establish a multivariate joint distribution model of the D-vine copula function for marine soft soil, and the effectiveness of the model was verified. This model offers flexibility for constructing multivariate joint distributions tailored to various characteristics of the correlation structure by leveraging several bivariate correlation structures. It can provide an effective method for accurately delineating the features of the correlation structure among multivariate geotechnical parameters and establishing a probabilistic transformation model for marine soft soil parameters. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation is one of the most attractive approaches to addressing the global freshwater shortage. However, achieving an integrated high evaporation rate, salt harvesting, and multifunctionality in evaporator is still a crucial challenge. Here, a novel composite membrane with biomimetic micro-nanostructured superhydrophobic surface is designed via ultrafast laser etching technology. Attractively, the double-transition-metal (V 1/2 Mo 1/2 ) 2 CT x MXene nanomaterials as a photothermal layer, exhibiting the enhanced photothermal conversion performance due to elevated joint densities of states, which enables high populations of photoexcited carrier relaxation and heat release, provides a new insight into the photothermal conversion mechanism for multiple principal element MXene. Hence, the (V 1/2 Mo 1/2 ) 2 CT x MXene-200 composite membrane can achieve a high evaporation rate of 2.23 kg m -2  h -1 under one sun, owing to the enhanced "light trap" effect, photothermal conversion, and high-throughput water transfer. Synergetically, the membrane can induce the directed precipitation of salt at the membrane edge, thus enabling salt harvesting for recycling and zero-emission of brine water. Moreover, the composite membrane is endowed with excellent multifunctionality of anti-/de-icing, anti-fouling, and antibacterial, overcoming the disadvantage that versatility is difficult to be compatible. Therefore, the evaporator and the promising strategy hold great potential for the practical application of solar evaporation., Competing Interests: Declarations. Conflict of Interest: The authors declare no interest conflict. They have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025. The Author(s).)