The reasonable value of good gradation characteristic parameters is key in designing and optimising soil-rock mixed high fill embankment materials. Firstly, the DJSZ-150 dynamic-static large-scale triaxial testing instrument was used for triaxial compression shear tests on compacted skeleton structure soil-rock mixture standard specimens. The changes in strength and deformation indicators under different gradation parameters and confining pressure were analysed. Then, based on the Janbu empirical formula, relationships between parameters K, n, and (sigma 1-sigma 3)ult and the coefficient of uniformity Cu and coefficient of curvature Cc were explored. Empirical fitting formulas for Duncan-Chang model constants a and b were proposed, establishing an improved Duncan-Chang model for soil-rock mixtures considering gradation characteristics and stress states. Finally, based on significant differences in particle spatial distribution caused by gradation changes, three generalised models of matrix-block stone motion from different particle aggregation forms were proposed. Results indicate the standard specimen's strength and deformation indicators exhibit significant gradation effects and stress-state correlations. The improved Duncan-Chang model effectively simulates the stress-strain relationship curve under different gradations and confining pressure, with its characteristics explainable based on the matrix block stone motion generalised model.

In this article, a one-dimensional non-isothermal diffusion model for organic pollutant in an unsaturated composite liner (comprising a geomembrane and an unsaturated compacted clay liner (CCL)) considering the degradation effect is established, which also includes the impacts of temperature on diffusion-related parameters, and employs a water content and pore-water pressure head relationship equation that better matches the experimental results. Subsequently, this model is addressed through a finite-difference technique, and its reasonableness is proved by comparing with the experiment measurements and two other calculation approaches. Following this, the analyses suggest that the diffusion coefficients' change induced by a rising temperature accelerates the diffusion rate, whereas such an alteration on partitioning coefficients has an opposite effect. Furthermore, the evaluation reveals that the non-isothermal state caused by an increasing upper temperature overall lowers the anti-fouling performance. The unsaturated composite liner's barrier function is weakened by an increment in residual water content of CCL, but enhanced by unsaturated layer thickness. It is also detected that the degradation effect should be considered if the degradation half-life <= 100 years. Lastly, a simplified approach for assessing the unsaturated composite liner's barrier performance is presented, which can provide guidance for its engineering design in a non-isothermal scenario.