秸秆纤维黏土混合料作为填埋场衬垫材料可行性研究  

Feasibility study of clay containing straw fiber as landfill liner material

作　　者：陆海军[1] 陈威[1] 董祎挈 

机构地区：[1]武汉轻工大学多孔介质力学研究所,湖北武汉430023

出　　处：《大连理工大学学报》2014年第3期323-328,共6页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(11002102);武汉市青年科技晨光计划资助项目(201271031419)

摘　　要：为保证填埋场衬垫防渗系统的安全性,采用秸秆纤维对压实黏土衬垫系统进行改良,以提高衬垫系统的承载能力及抗开裂特性.通过无侧限抗压强度试验、直剪试验、固结试验与抗开裂试验,探讨了秸秆纤维改良黏土的强度特性、变形特性和抗开裂特性,并以此对秸秆纤维黏土混合料作为填埋场衬垫材料的可行性进行评价.试验结果表明,秸秆纤维改良黏土具有较高的承载能力与抗开裂能力,秸秆纤维黏土混合料可以作为填埋场衬垫材料.秸秆纤维掺量对改良黏土的强度特性影响显著,随纤维掺量的增加,改良黏土的无侧限抗压强度先增大后减小,破裂形态由脆性破坏逐渐过渡为塑性破坏;黏聚力c、内摩擦角φ、压缩模量Es先增大后减小;压缩系数αv、压缩指数Cc则出现先减小后增大的趋势.最佳秸秆纤维掺量为0.30%,此时改良黏土的最大抗压强度达到459.15kPa,满足填埋场衬垫的工程强度要求.秸秆纤维掺量为0.30%的改良黏土,其开裂因子仅为0.008 1.For the purpose of operating impervious system of the landfill liner safely,improving bearing capacity and anti-cracking characteristics of the landfill liner,straw fiber was chosen as liner system of modified compacted clay.Through unconfined compressive test,direct shear test, consolidation test and anti-cracking test,strength,deformation and anti-cracking characteristics of modified clay with straw fiber were observed to evaluate the feasibility of straw fiber clay mixture as landfill liner material.Experimental results show that straw fiber clay mixture can be used as landfill liner material with higher bearing capacity and anti-cracking ability.Strength characteristics of modified clay are influenced significantly by the content of straw fiber.With the increase of fiber content,unconfined compression strength of modified clay increases firstly and then decreases; fracture morphology transforms gradually from brittle fracture to plastic failure;cohesion c,internal friction angleφand compression modulus Esincrease firstly and then decrease;compression coefficient αv,compressive index Ccfirstly decrease and then increase.The best content of straw fiber is 0.30%. At this time the maximum compressive strength of modified clay reaches 459.15kPa to meet the requirements of landfill liner about engineering strength.For the modified clay with 0.30% of straw fiber content,the cracking factor is only 0.008 1.

关 键 词：填埋场衬垫 秸秆纤维 改良黏土 承载能力 开裂因子 

分 类 号：TV131.2[水利工程—水力学及河流动力学]