欠固结淤泥质吹填土压缩-渗透非线性特性试验研究ExperimentalStudyonNonlinearCharacteristicsofPemeabilityandCompressibilityofSoftClay领域:水利工程作者姓名:路江鑫导师:夏开文教授企业导师:侯晋芳高工天津大学建筑工程学院二零壹伍年拾贰月独创性声明本人声明所呈交的学位论文是本人在导师指导下进行的研究工作和取得的研究成果,除了文中特别加以标注和致谢之处外,论文中不包含其他人已经发表或撰写过的研究成果,也不包含为获得天津大学或其他教育机构的学位或证书而使用过的材料。与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示了谢意。学位论文作者签名:签字日期:年月日学位论文版权使用授权书本学位论文作者完全了解天津大学有关保留、使用学位论文的规定。特授权天津大学可以将学位论文的全部或部分内容编入有关数据库进行检索,并采用影印、缩印或扫描等复制手段保存、汇编以供查阅和借阅。同意学校向国家有关部门或机构送交论文的复印件和磁盘。(保密的学位论文在解密后适用本授权说明)学位论文作者签名:导师签名:签字日期:年月日签字日期:年月日摘要随着沿海地区经济建设迅速发展及城镇化进程的加快,内河航道清淤疏浚及滩涂浅海区围海造陆工程大规模推进,吹填厚度越来越大。加固前吹填淤泥尚处于流动状态,其含水量远大于液限,属于欠固结土。通过试验发现,吹填淤泥在小应力阶段,压缩-渗透非线性变化较大,与大应力状态下存在较大差别,工程实际表明,采用大应力状态下渗透系数和压缩系数来计算吹填土的固结问题存在较大偏差。传统的固结理论假定压缩系数和渗透系数为常数,没有考虑土体压缩渗透非线性特性,不符合实际。本文以天津滨海新区围海造陆工程为背景,对不同吹填区土质做了充分调研,选取具有代表性的东疆港区(TJDG)、临港工业区(TJLG)、南港工业区(TJNG)吹填土为试验土样,利用GDS高级固结仪对吹填土的固结渗透特性开展试验研究。具体研究内容为:(1)基于GDS高级固结仪对三种不同液限(41.50%、50.25%、46.75%)吹填土开展连续的固结渗透试验,得到不同液限吹填土在特定固结压力下或孔隙比下的渗透系数。(2)基于试验结果,对吹填土压缩渗透特性进行分析探讨,采用4种非线性渗透模型及3种非线性压缩模型对试验数据进行线性拟合及综合分析并确定模型参数,获得适用于天津地区吹填土的最佳非线性压缩、渗透关系。(3)通过对模型参数对比分析,发现同一模型不同液限土体,模型参数不同,为研究软黏土压缩性、渗透性随土质和孔隙比变化的普遍规律,采用液限孔隙比eL对试验数据进行归一化处理,引入归一化参数e/eL,提出采用Chapman-Richard成长模型对吹填土压缩性、渗透性进行描述。建立了吹填土kv-e/eL拟合方程及e/eL-p关系拟合曲线。(4)针对基于Chapman-Richard成长曲线获得的吹填土kv-e/eL及e/eL-p拟合方程,收集和整理国内外29组渗透试验数据及12组高含水量软黏土压缩试验数据对其有效性进行验证,得到具有普适性的软黏土压缩性及渗透系数预测表达式,并分别在e=1.3eL(接近液限)、e=eL(液限)处将曲线采用简化的双线性进行描述,同时赋予其物理意义。关键词:吹填土渗透系数Chapman-Richard成长模型固结双线性ABSTRACTWiththerapiddevelopmentofeconomicandconstructionincoastalareas,ThescaleandtechnologyofreclamationhaveachievedavigorousdevelopmentinChina.Dredgedsiltisinastateofflowanditswatercontentismuchbiggerthanitsliquidlimit,whichisunderconsolidatedsoil.Ithasbeenfoundthatthenonlinearcharacteristicsofpermeabilityandcompressibilityofdredgefillunderlowerstressaredifferentcomparedwiththehigherstress.Thepracticalapplicationshowsthatthetraditionalsmall-strainconsolidationtheorytopredictcompressibilityandpermeabilityofdredgefillwasusuallyunsuitableforclayslurryconsolidatedwitheffectivestress.Inthispaper,relyingontheconstructionoflandreclamationinTianjin,China,threespecimenswithdifferentliquidlimitsaretakenfromthreelandreclamationsites,I.e.Lingang(TJLG),Nangang(TJNG),Donggang(TJDG)inTianjinforthepresentstudies.The1-Dconsolidationandpermeabilitytestsareconductedinanewconsolidationtestingsystem(modelGDSCTS)producedbyGDSInstrumentsPteLtd,UK.Thedetailedcontentsareasfollows:(1)Consolidationandpermeabilitytestswereconductedonsoftclayswithdifferentliquidlimit(41.50%,50.25%,46.75%)byGDSconsolidationapparatus.Thecoefficientofpermeabilityofsoilspecimenunderthegivenconsolidationpressureisobtained.(2)Regressionfittinganalyseson4commonnonlinearpermeabilitymodelsand3nonlinearcompressibilitymodelswereperformedbasedonthetestdata.ThepreferrednonlinearfunctionrelationshipsfordredgedfillinTianjinBinhaidistrictareobtained.(3)Comparingwiththefittingparameters,soilsampleswithdifferentliquidlimitshavedifferentparametersforthesamemodel.Inordertofindtheuniversallawofpermeabilitycoefficientandcompressibilitywiththesoilpropertyandvoidratio,ThevoidratiowasnormalizedbytheliquidvoidratioeL,andtherelationshipsofe/eLwithlogkvandlogpwereestablishedbasedonthetestdatathroughtheChapman-Richardcurvefittingmodel.(4)Therelationshipsofe/eLwithlogkvandpwerefurtherverifiedusing29groupsoftestdataofpermeabilityand12groupsoftestdataofcompressibilitycollectedfromChinaandabroad.Relativelygoodagreementsareachieved.Theobtainedlogkvvs.e/eLandlogpvs.e/eLrelationshipscanbesimplifiedtobilinearequationswiththeirintersectionpointone/eL=1.3ande/eL=1.0respectively.Theproposedrelationshipscanbeusedaspreliminarytoolstocalculatethecompressibilityandpermeabilityofreconstitutedmarineclayencounteredinlandreclamationprojects.KEYWORDS:PermeabilityCoefficient,DredgedFill,Chapman-RichardModel,Consolidation,BilinearEquations目录第一章绪论.......................................................11.1研究背景..............................................................................................................11.2国内外研究现状..................................................................................................31.2.1软黏土压缩特性研究进展...........................................................................31.2.2软黏土渗透特性研究进展...........................................................................51.2.3饱和软黏土压缩-渗透特性预测公式研究进展.........................................81.3研究的必要性和主要内容................................................................................10第二章基于GDS固结仪的淤泥质吹填土固结-渗透联合测试试验.........122.1试验土样............................................................................................................122.2GDS一维固结渗透试验系统...........................................................................132.2.1硬件系统.....................................................................................................142.2.2软件系统.....................................................................................................162.2.3试验操作原理..............................................................................