酸雨浸泡作用下云南红土的剪切特性

Yunnan laterite's shear character under the acid rain

根据云南省酸雨特点配制模拟酸雨溶液,考虑时间、pH值两个因素,采用浸泡的试验方法,研究酸雨作用下云南红土抗剪特性变化,最后对酸雨-红土间的作用机理进行分析.试验结果表明,总体上酸雨浸泡降低了红土的抗剪强度及其特征参数.酸雨pH越小,浸泡时间越长,红土抗剪强度折减越多;抗剪强度及其特征参数随pH值增大而波动增大,质量随pH值增大而先减小后增大;浸泡第1 d时,红土抗剪强度及其特征参数折减幅度最大,之后随浸泡时间增加而波动变化,质量随浸泡时间增加而波动减小;为解释上述几个结果,特对酸雨-红土相互作用过程进行分析,将其归结为酸雨-红土物理作用、酸雨-红土化学作用、酸雨-红土盐类溶解、置换、结晶等.

According to the feature of acid rain in Yunnan,acid rain solutions were prepared,and the soaking tests of Yunnan laterite were performed. The shear characteristics of Yunnan laterite was discussed under acid rain soaking condition,and the interaction mechanisms between acid rain and laterite were studied. The results showed that the shear characteristics of laterite and its related index were reduced after acid rain soaking. The small pH of acid rain and the long soaking time result in the reduction of shear characteristics. With the increase of the pH value,the shear characteristics and its related index fluctuating increased, and the mass of laterite decreased first and then increased. The shear characteristics of laterite and its related index decreased most on the first soaking day,and later fluctuating changed and the mass fluctuating decreased. In order to explore the reasons,the interaction process between acid rain and laterite was analyzed. The results showed that the physical action,chemistry action,and salt dissolution,exchange,crystallization action happened between acid rain and laterite,which generally produced the water-laterite softening,the water-laterite chemical reaction, the acid-laterite chemical reaction, the acid-laterite salt dissolution,exchange,crystallization and so on.