酸性污染土物理力学性质的室内试验研究

基于上海地区浅层软粘性土较易被污染,且通常工业污染中以硫酸污染最为严重这一原因,选用该地区浅层典型的淤泥质粉质粘土,通过室内浸泡方法制备酸性污染土,系统研究了不同浓度硫酸溶液、不同侵蚀时间对土体物理力学性质的影响,研究表明:随酸侵蚀时间的推移,土的含水量、孔隙比、液塑限都是随硫酸浓度的增加而增加;土的圆锥入土深度随着浸泡时间的延长、酸液浓度的增加而加大,微型十字板强度减小,直剪固快试验结果规律不明显;压缩系数随浸泡时间的延长呈增大的趋势,压缩模量呈减小的趋势,而压缩系数和压缩模量随酸液浓度的变化规律不明显.同时对污染土几种强度试验方法的有效性进行对比分析,表明直剪固快试验有效性差;微型十字板试验和圆锥入土深度试验结果相吻合,有效性好,建议采用微型十字板和圆锥入土深度试验进行污染土室内强度试验.

Research on physical-mechanical property of soil contaminated by acid in laboratory

In view of the Shanghai area shallow layer soft soil is easy to be polluted,and usually industrial pollution in sulfuric acid pollution is most serious,the region of the superficial layers of typical of silty clay was selected through indoor soaking method for preparing acidic pollution soil,the different concentration of sulfuric acid solution erosion was studied on different time physical and mechanical properties of soil,it showed that,with the acid corrosion time,soil water content,void ratio,liquid,plastic limit are with the sulfuric acid concentration increase with increasing soil depth;the cone with the extension of soaking time,acid concentration increase,the miniature cross board reduce strength,direct shear test results of solid fast not clear;compression coefficient with the extension of soaking time is increased,the compression modulus decrease,and the compression coefficient and compression modulus with acid concentration is not obvious.At the same time for pollute soil several strength test method is effective for comparative analysis,showed that direct shear test of solid fast differential validity;miniature vane test and cone penetration depth test results match,good effectiveness,recommende the use of miniature cross plate and tapere depth test pollution soil strength test.