工业废渣在湖相软土固化改良中的应用研究

Application study on industrial waste residue in the solidification andimprovement of lacustrine soft soil

为改善湖相软土承载力小、易压缩变形、含水率大的工程特性,提出采用粒化高炉矿渣(GGBS)作为主固化材料,电石渣和Na_(2)SO_(4)作为激发剂材料对湖相软土进行复配固化改良,并与水泥固化方案进行了工程性能对比试验。结果表明:单掺GGBS、电石渣或者Na_(2)SO_(4)均能提升软土强度,分别在12%、2.5%和4%掺量时达到强度最大值,但对于强度的提升程度较小;当采用GGBS(12.18%)+电石渣(2.3%)+Na_(2)SO_(4)(5.31%)的复配方案时,强度提升较为显著,28d龄期强度可以达到1107kPa,是原状软土的24.6倍,其强度改善效果与掺入13%水泥的固化改良效果相当;采用GGBS+电石渣+Na_(2)SO_(4)进行复配固化的软土稳定性强于采用水泥固化的软土,在经历9次干湿循环后,强度仅降低7kPa,而水泥固化组则降低了86kPa,复配固化改良软土具有更优越的工程力学性能。

In order to improve the engineering characteristics of low bearing capacity,easy compression deformation and high moisture content of lacustrine soft soil,it is proposed to use granulated blast furnace slag(GGBS)as the main solidification material,carbide slag and Na_(2)SO_(4)as activator materials for composite solidification and improvement of lacustrine soft soil.Engineering performance comparison tests are conducted with cement solidification schemes.The results show that single addition of the GGBS,carbide slag,or Na_(2)SO_(4)can all improve the strength of the soft soil,reaching the maximum strength at 12%,2.5%and 4%dosage respectively,but the degree of strength improvement is relatively small;When using the composite scheme with the GGBS(12.18%)+carbide slag(2.3%)+Na_(2)SO_(4)(5.31%),the strength improvement is significant,and the strength at 28 days can reach 1107 kPa,which is 24.6 times that of undisturbed soft soil.The strength improvement effect is equivalent to the solidification improvement effect with adding 13%cement;The stability of the soft soil stabilized with GGBS+calcium carbide slag+Na_(2)SO_(4)composite is stronger than that of the soft soil stabilized with cement.After 9 dry wet cycles,the strength only decreases by 7kPa,while the cement solidification group decreases by 86kPa.The composite solidification-improved soft soil has superior engineering mechanical properties.