| 张芊,陆海军,李继祥,张雄.渗沥液污染下水泥固化高岭土透水及变形特性[J].,2016,56(5):510-517 |
| 渗沥液污染下水泥固化高岭土透水及变形特性 |
| Hydraulic and deformation characteristics of kaolin solidified with cement under leachate pollution |
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| DOI：10.7511/dllgxb201605011 |
| 中文关键词: 水泥 高岭土 渗沥液 渗透 变形 |
| 英文关键词: cement kaolin leachate permeation deformation |
| 基金项目:国家自然科学基金资助项目(5147416811672216)；中国科学院岩石力学与工程国家重点实验室开放研究课题(Z014007,Z015006)；湖北省百人计划资助项目. |
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| 中文摘要: |
| 针对填埋场衬垫在高荷载作用下开裂破坏的现状，采用水泥固化高岭土，评价其抗渗、抗开裂及固结压缩特性，探究其作为填埋场衬垫材料的可行性．采用纯高岭土与水泥掺量5%、10%、15%的固化高岭土进行试验，室内模拟填埋场衬垫受渗沥液污染的工况，通过渗透试验测定水力传导系数，分析其抵抗污染物渗透能力；通过固结试验测定压缩系数，分析其固结压缩特性；通过干湿循环开裂试验测定开裂因子，分析其抵抗开裂变形特性．结果表明 试样水力传导系数随时间增加而下降，其中纯高岭土下降40.4%，而水泥固化后高岭土仅下降16.0%~27.1%．由于试验高岭土属于中压缩性土，试样孔隙比随荷载压力上升而下降，水泥掺量越多，孔隙比下降越少，200 kPa荷载下，0.25~64 min的轴向位移变化量占总变化量的65.1%~70.7%；掺入水泥后试样的开裂面积明显减小，最大开裂因子降幅达52.6%，水泥掺量10%与15%的试样开裂因子差别较小．水泥固化后高岭土的强度及抗开裂能力提高，满足作为填埋场衬垫材料的要求． |
| 英文摘要: |
| To solve the problem of landfill liner cracking caused by high loading, the hydraulic, cracking and consolidation compression characteristics of kaolin solidified with cement are explored, and the feasibility of the solidified kaolin used as landfill liner-soil material is evaluated. The kaolin and the solidified kaolin containing 5%, 10%, 15% cement are tested in the condition of simulated cases with leachate pollution. Penetration tests are performed to evaluate hydraulic conductivity and the resistance to contaminants permeability of samples. Compression coefficient and consolidation compression characteristics of samples are analyzed by consolidation test. Moreover, through cracking tests in drying-wetting circles, cracking intensity factor and anti-cracking properties of samples are analyzed. Based on the results of tests, hydraulic conductivity of kaolin decreases by 40.4% with the increase of time, while that of the solidified kaolin containing cement decreases 16.0%-27.1%. Since kaolin used in tests belongs to medium compressible soil, void ratio of samples decreases with the increase of load, and the more the content of cement is, the smaller the decrease in void ratio of samples is. The axial displacement changes between 0.25 min and 64 min account for 65.1%-70.7% of the total at 200 kPa. The cracking area of samples reduces after adding cement, and the maximum cracking intensity factor drops by 52.6%. The difference between the solidified samples containing 10% and 15% cement is small. Whereas the strength and anti-cracking ability of kaolin are improved, the solidified kaolin containing cement can be used as landfill liner-soil material. |
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