The material foundation of soil and water conservation is built on the integrity of the highway plant slope. The proportional relevance of the components that affect slope quality was evaluated based on an environmental assessment and the actual characteristics of the highway slope. A system of four major indexes and twelve secondary indexes comprising plant traits, geometric factors, hydrological conditions, and vegetation conditions was developed to assess the stability of roadway plant slopes. The rough set theory approach and the analytic hierarchy process were used to solve the weights of the slope evaluation indexes. Based on a rough set and an analytic hierarchy process, an evaluation model is proposed. The model eliminates the inconsistency and uncertainty in the evaluated factors that are used to calculate the slope. The study was conducted in China. The highway plant slope of the Taihang Mountain highway in the Hebei province was evaluated using the assessment model after dividing the highway plant slope stability into four grades. According to the evaluation results, the model can be used as a reference highway plant slope stability study and provide technical help to prevent and lower slope safety accidents. The evaluation model can predict the slope quality of highway plants, demonstrating the efficacy and reliability of the evaluation methodology and approach.

In order to study distribution regularity of heterogeneity of micro-structure of asphalt mixture, this paper which is based on fractal theory starts with aggregate distribution of asphalt mixture, and calculates fractal dimension of aggregate of ten groups of asphalt mixture in AC-16C type by using double log coordinates. It will evaluate indirectly heterogeneity of asphalt mixture through the analysis of correlation between fractal dimension of aggregate and aggregate distribution. The study results indicate that with the enlargement of fractal dimension of aggregate, the ability of space stuffing will strengthen, the closely knit degree of aggregate strength; as the decrease of flat and elongated particle in coarse aggregate, the possibility of aggregate being crushed will drop, which will improve the homogeneity of asphalt mixture and decrease the possibility of early damage of asphalt mixture.

In order to study the tensile properties of a high-density polyethylene (HDPE) geonet for rainwater scour resistance and the micro properties of HDPE after tensile failure, a series of tensile tests on the HDPE geonet were carried out by the material testing system (MTS) tensile device. In this study, a correlation has been proposed to analyze the relationship between elongation and tensile strength of geonet material. The microscopic characteristics of the HDPE geonet were observed by using a scanning electron microscope SU8000. The high-density polyethylene geonet for rainwater scour resistance was evaluated based on mechanical performance and microstructure. The rainwater scour resistance properties of the high-density polyethylene geonet were estimated. It is determined that the geonet improved the rainwater scour resistance of the soil slope. The mechanical test results indicated that the longitudinal mechanical properties of the geonet are better than the transversal. The scanning electron microscope images of the geonet results confirmed that the polyethylene polymer produces fine and neat radial cracks during the tensile process of the geonet. The findings of this work are essential for the fundamental understanding, design, and application of the geonet.