护坡人工混凝土壤不同粒级团聚体分布特征及其抗蚀性研究

为了定量评价人工混凝土壤生态护坡基材的抗蚀性，室内测定了其团聚体分布特征和各抗蚀性指标，并与立地条件相似的自然土壤进行了对照分析。结果表明:与自然土壤相比，人工混凝土壤中 > 0.25 mm机械稳定性团聚体含量、> 0.25 mm水稳性团聚体含量R_0.25、平均重量直径MWD、几何平均直径GWD与有机质含量均显著提升，可蚀性因子K、结构破坏率PAD、分形维数D与分散率均显著降低；同时，抗蚀性主成分值提高了2.53倍。这均证实人工混凝土壤团聚状况和团聚度有所改善，抗蚀性较自然土壤有较大的提升。相关性分析表明 > 0.25 mm水稳性大团聚体含量R_0.25和有机质含量与其他抗蚀性指标之间均存在极显著的相关性。综合分析可知，由于添加了水泥和天然有机物料，人工混凝土壤的水稳性大团聚体含量和有机质含量明显提升，因此导致其稳定性与抗蚀性显著优于原材料之一的自然土壤。

Influence of Vegetation-growing Concrete on the Distribution and Anti-erodibility of Aggregates

In order to quantitatively evaluate the erosion resistance of base materials on the ecological concrete protection slope, the aggregates distribution characteristics and various erosion resistance indices were analyzed in laboratory, compared with the natural soil with similar site conditions. The results showed that the proportions of > 0.25 mm mechanical stability aggregates and > 0.25 mm water-stable aggregates, mean weight diameter (MWD), geometric mean diameter (GWD), and organic matter in the vegetation-growing concrete were higher than those in the natural soil. However, the structural failure rate (PAD), erodibility factor (K), dispersion rate, and fractal dimension (D) in the vegetation-growing concrete were significantly lower than those in natural soil. The principal component value of anti-erodibility of vegetation-growing concrete was 2.5 times higher than that of natural soil, indicating that the vegetation-growing concrete improved aggregation degree, and increased its anti-erodibility. Correlation analysis showed that the proportion of > 0.25 mm water-stable macroaggregates and organic matter were closely related to the other anti-erodibility indicators. Hence, the addition of natural organic materials and cement significantly increased the content of organic matter and the proportion of water-stable macroaggregates of vegetation-growing concrete, resulting in significantly better aggregate stability and anti-erodibility compared with that of natural soil.