(1. School of Civil Engineering，Hexi University，Zhangye，Gansu 734000，China；
2. School of Resources and Safety Engineering，Chongqing University，Chongqing 400030，China；
3. State Key Laboratory of Coal Mine Disaster Dynamics and Control，Chongqing University，Chongqing 400030，China)
Abstract：The mechanical properties of stored tailings are the key factors that affect the stability of the tailings dam. Based on the method of chemically improving soil mechanical properties，the mechanical properties of the polymer improved tailings were studied. Results show that the shear strength of tailings improved by polyvinyl alcohol and sodium carboxymethyl cellulose is smaller than that of unimproved tailings. But the shear strength of the tailings improved by polyacrylamide and calcium lignin sulfonate are increased. Compared with the shear strength parameters of unimproved tailings，the cohesion of the tailings improved by polyacrylamide，sodium carboxymethyl cellulose，calcium lignin sulfonate are increased. The cohesion of the polyvinyl alcohol improved tailings is decreased. The internal friction angle of the polyacrylamide and calcium lignin sulfonate improved tailings are increased. The internal friction angle of the tailings improved by sodium carboxymethyl cellulose and polyvinyl alcohol is decreased. Among the four kinds of polymer materials，the improvement effect of polyacrylamide is most significant. After curing for 7 days，the mechanical properties of polyacrylamide-improved tailings tended to be stable. The shear strength of improved tailings increases with the increase of polyacrylamide concentration. Additionally，the results of immersion test，dry-wet cycle test and freeze-thaw cycle test show that polyacrylamide-improved tailings have good water stability and aging resistance.
MIRZABABAEIA M，ARULRAJAH A，OUSTON M . Polymers for stabilization of soft clay soils[J]. Procedia Engineering，2017，189：25–32.
[9]
REIS L G，OLIVEIRA R S，PALHARES T N，et al. Using acrylamide/propylene oxide copolymers to dewater and densify mature fine tailings[J]. Minerals Engineering，2016，95：29–39.
[7]
TA'NEGONBADI B，NOORZAD R. Stabilization of clayey soil using lignosulfonate[J]. Transportation Geotechnics，2017，12：45–55.
[2]
SHAMSAI A，MOHYEDDIN B，AYATOLLAHI S，et al. Geotechnical characteristics of copper mine tailings：a case study[J]. Geotechnical and Geological Engineering，2007，(25)：591–602.
[6]
VINOD J S，INDRARATNA B，MAHAMUD M A A. Stabilisation of an erodible soil using a chemical admixture[J]. Proceedings of the Institution of Civil Engineers-Ground Improvement，2010，163(1)：43–51.
[1]
YIN G，WEI Z，WANG J G. Interaction characteristics of geosynthetics with fine tailings in pullout test[J]. Geosynthetics International，2008，15(6)：428–436.
[3]
LEI H Y，XU Y G，LI X，et al. Effects of polyacrylamide on the consolidation behavior of dredged clay[J]. Journal of Materials in Civil Engineering，2018，30(3)：04018022.
[5]
CRUSE R M，LARSON W E. Effect of Soil Shear Strength on Soil Detachment due to Raindrop Impact[J]. Soil Science Society of America Journal，1977，41 (4)：777–781.
[8]
张 涛. 基于工业副产品木质素的粉土固化改良技术与工程应用研究[博士学位论文][D]. 南京：东南大学，2015.(ZHANG Tao. Study on Technology and engineering application of silt solidified by lignin[Ph. D. Thesis][D]. Nanjing：Southeast University，2015.(in Chinese))
[10]
DWARIA R K，ANGADIA S I，TRIPATHY S K. Studies on flocculation characteristics of chromite’s ore process tailing：effect of flocculants ionicity and molecular mass[J]. Colloids and Surfaces A，2018，537：467–477.
[11]
DASH M，DWARI R K，BISWAL S K，et al. Studies on the effect of flocculant adsorption on the dewatering of iron ore tailings[J]. Chemical Engineering Journal，2011，173(2)：318–325.
[13]
申培武，唐辉明，汪丁建，等. 巴东组紫红色泥岩干湿循环崩解特征试验研究[J]. 岩土力学，2017，38(7)：1 990–1 998.(SHEN Peiwu，TANG Huiming，WANG Dingjian，et al. Disintegration characteristics of red-bed mudstone of Badong Formation under wet-dry cycles[J]. Rock and Soil Mechanics，2017，38(7)：1 990–1 998.(in Chinese))
[15]
董金梅，徐洪钟，朱定华，等. 不同水环境下高分子材料改性粉土的试验研究[J]. 岩土工程学报，2013，35(7)：1 316–1 322.(DONG Jinmei，XU Hongzhong，ZHU Dinghua，et al. Experimental study on silty soil modified by polymer materials under varying water environments[J]. Chinese Journal of Geotechnical Engineering，2013，35 (7)：1 316–1 322.(in Chinese))
[12]
中华人民共和国行业标准编写组. GB/T50123－2019土工试验方法标准[S]. 北京：中国计划出版社，2019.(The Professional Standards Compilation Group of People?s Republic of China. GB/T50123－2019 Standard for geotechnical testing method[S]. Beijing：China Planning Press，2019.(in Chinese))
[14]
许 雷，刘斯宏，鲁 洋，等. 冻融循环下膨胀土物理力学特性研究[J]. 岩土力学，2016，37(增2)：167–174.(XU Lei，LIU Sihong，LU Yang，et al. Physico-mechanical properties of expansive soil under freeze-thaw cycles[J]. Rock and Soil Mechanics，2016，37(Supp.2)：167–174.(in Chinese))
2020, Vol. 39 
