有机磷农药污染黄土的强度及微观特性研究

为研究农药污染土的力学特性，开展了有机磷农药(草甘膦、草铵膦)不同含量、压实度、含水率、养护龄期条件下黄土的无侧限抗压强度试验，并对试样进行了微观结构分析。结果表明：污染黄土无侧限抗压强度随农药含量的增加而减小，草甘膦与草铵膦两种农药影响效果相似。污染黄土无侧限抗压强度随压实度和养护龄期的增加而增大，随含水率的增加而减小且逐渐趋于平缓。通过微观结构分析发现，农药侵入土体并未改变土中的矿物成分，而是吸附于土中的黏粒矿物上，与矿物层间离子发生反应，从而降低了层间的支撑作用，使得土体颗粒更为破碎，土中大孔隙增多、颗粒排列更加分散导致了土体强度的降低。

Strength and microscopic properties of loess contaminated by organophosphorus pesticides

In order to study the mechanical properties of pesticide-contaminated soil, the unconfined compressive strength test was carried out on loess under different organophosphorus pesticide(glyphosate, glufosinate) contents, compaction degrees, moisture contents and curing time. In the meantime, the microstructural characteristics of contaminated soils were also explored. The results show that the unconfined compressive strength of the contaminated soil decreases with the increase of pesticide content, and the influence of glyphosate on the soil is similar to that of glufosinate. The unconfined compressive strength of the contaminated soil increases with the increase of compaction degree and curing time, but decreases and levels off with the increase of moisture content. Microstructural analysis reveals that pesticide intrusion into the soil does not change the mineral composition of the soil, but adsorbs on the clay mineral particles in the soil, and reacts with the mineral interlayer ions to reduce the interlayer column support. Therefore, the addition of pesticides makes the particles more fragmented, increases the number of large pores in the soil, disperses the particles and reduces the strength of the soil.