酸雨对河道淤泥气泡混合土工程性质的影响

Influence of acid rain on engineering properties of foamed light soil with river sludge

通过渗滤法考察模拟酸雨对河道淤泥气泡混合土的侵蚀作用,试验过程中测定混合土试样的物理力学指标、渗滤液的pH值和Ca^(2+)浓度值以及矿物组分受酸雨渗滤影响后的变化规律,研究考察酸雨对混合土性质的影响。试验结果表明:酸雨导致河道淤泥气泡混合土中的矿物水解并以Ca^(2+)离子形式析出,导致混合土中性化。酸雨的酸性越强,土体中性化程度越高,在中性化过程中又有新的矿物生成,使混合土中矿物相对含量发生改变,导致混合土物理力学性质的变化;与正常雨水作用相比,经酸雨作用后的河道淤泥气泡混合土含水率和密度升高,强度降低,破坏模式向脆性化发展,并且酸雨的酸性越强,物理力学性质的变化越明显。

Impact of acid rain on foamed light soil with river sludge(FMLSS)was studied by percolation method.Physical and mechanical indexes of specimens,pH value and Ca 2+concentration of leachate,as well as the change of mineral composition of FMLSS after acid rain infiltration were measured during test,to investigate the influence of acid rain on properties of FMLSS.Experimental results show that acid rain results in the hydrolysis of minerals and dissolution in the form of Ca 2+ions leading to neutralization of FMLSS.It is found that the stronger the acidity of simulated acid rain,the higher the degree of neutralization.At the same time,new minerals are generated in the process of neutralization,which changes the relative content of minerals in the mixed soil and leads to the changes of physical and mechanical properties.Compared with those in the normal water condition,moisture content and density increase,while the peak strength decreases.In addition,the failure mode evolves to the brittle type after acid rain.Based on the results,it can be safely arrived at that the stronger the rain acidity,the greater the degree of physical and mechanical changes.