Functionality Optimizing Study On Coal-bearing Soil Ecological Substrates

Abstract

Ecological restoration is of profound significance for protecting the ecology and engineering safety of coal-bearing soil (CBS) areas. However, the formulations of CBS ecological substrates have rarely been explored. The objective of this study was therefore to evaluate the effects of the CBS:soil ratio (1000:0 g, 750:250 g, 500:500 g, 250:750 g), fly ash content (0, 50 g·kg− 1, 100 g·kg− 1, 150 g·kg− 1), maize straw content (0, 20 g·kg− 1, 40 g·kg− 1, 60 g·kg− 1), and expanded polystyrene (EPS) content (0, 3 g·kg− 1,6 g·kg− 1, 9 g·kg− 1) in an orthogonal design to optimize an ecological substrate according to various physicochemical, nutrient content, mechanical, and vegetation parameters. The results indicated that the CBS:soil ratio had significant effects on the nutrient content and vegetation growth parameters; fly ash dramatically improved the mechanical parameters (shear strength, cohesion, and internal friction angle); maize straw significantly affected the physical parameters and improved the substrate nutrient content; and EPS was the most beneficial to the vegetation germination ratio. A CBS:soil ratio of 1:1 (500:500 g), fly ash content of 100 g·kg− 1, maize straw content of 50 g·kg− 1, and EPS content of 6 g·kg− 1 were determined to produce the optimal mix for the ecological restoration of CBS. The conclusions of this research provide theoretical and practical guidance for the ecological restoration and stabilization protection of CBS slopes.