作　　者： (陈波）; (孙德安）; (高游）; (李健）;

机构地区： 衢州学院建筑工程学院,浙江衢州324000 上海大学土木工程系,上海200444

出　　处： 《岩土力学》 2017年第9期2523-2530,共8页

摘　　要： 为研究结构性对软黏土变形特性的影响,对上海软黏土原状样和不同制样方式得到的重塑样、泥浆样和压实样开展了压缩试验和压汞试验,确认固结压力和制样方式对软黏土的孔径大小及分布具有重要影响。试验结果表明:上海软黏土原状样的孔径分布为单峰孔径分布,孔径大小主要分布在0.01~1.00?m之间;结构性对孔径分布影响较大,随着固结压力的增大,大孔隙和中孔隙逐渐向小孔隙转化,尤其是固结压力大于结构屈服应力后,这种现象更加明显;不同制样方法得到的重塑样、泥浆样和压实样,在饱和状态下的孔径分布均为单峰孔径分布,但不同制样方式得到的土样孔径分布差别较大,压实样的孔径相对较大,泥浆样的孔径分布较为集中;随着固结压力的增大,不同制样方法在相近孔隙比下的土样孔径分布差别虽然有所减小,但仍无法达到相同或接近,即固结压力无法消除制样方式对土体孔径分布的影响。用简单表示组构的参考孔隙比对不同土样的压缩曲线进行归一化整理,得到4种土样的压缩曲线可归一化为一条相关度极高的直线,说明参考孔隙比用于简单表述土体的组构是合理、有效的。 To study the effect of soil structure on deformation characteristics,a series of odometer and mercury intrusion porosimetry tests on undisturbed,remolded,reconstituted and compacted samples of Shanghai soft clay,was carried out to obtain the compression curves and the pore-size distributions（PSD） of samples.The test results show that consolidation pressures and sample preparations have important influence on the PSD curves,and the PSD of undisturbed sample of Shanghai soft clay exhibits a unimodal shape,with a pore-size mainly ranging from 0.01 to 1.0 ？m.The unimodal PSD of undisturbed sample is greatly influenced by soil structure.Large and medium interparticle pores are compressed into the small interparticle pores with increasing consolidation pressures,particularly under the consolidation pressure larger than the structural yield stress.The unimodal PSD also was found in saturated soft clay,no matter undisturbed,remolded,reconstituted or compacted samples.However,the PSD curves of samples using different sample preparation methods are different.The compacted samples have larger pore size and the reconstituted samples generate uniform pore size.The differences of micro-pore structure among different samples will be reduced with increasing consolidation pressure,yet never eliminated even at large consolidation pressure.Lastly,the reference void ratio,i.e.,a simple expression of clay fabric,is used to normalized the compression curves of the samples with different preparation.Different compression curves of four types＇ samples are normalized to a high correlative unified compression curve,which shows that the reference void ratio is a reasonable and effective parameter to illustrate the PSD of clay.

关 键 词： 上海软黏土 压汞试验 孔径分布 结构性 参考孔隙比