摘要
对连云港软黏土不扰动样和重塑样进行三轴CU对比试验研究。结果表明,不扰动样的不排水强度包线是由以屈服压力为界的双折线组成,而重塑样的不排水强度包线可以用通过圆点的直线表示。屈服前阶段,不扰动样由于受结构性影响产生的抵抗作用,其不排水强度包线高于重塑样;屈服后阶段,不扰动样的不排水强度包线介于具有不同初始含水率的重塑样的包线之间。通过对比分析,发现不扰动样与重塑样的不排水强度包线存在差异的主要原因是由于试样的不同初始含水率引起的。不扰动样在屈服后阶段的含水率变化规律与不排水强度增长规律与重塑土相一致,采用Burland提出的孔隙指数Iv,可将不同初始含水率重塑样及屈服后阶段不扰动样的压缩性状较好地归一化。
Triaxial consolidation undrained shear tests were performed on both undisturbed and remolded samples of soft Lianyungang clay to investigate its undrained shear strength behavior. The test results indicated that the strength envelope of the undisturbed sample is composed by two straight lines separated by the triaxial consolidation yield stress. The strength envelopes of remolded samples, however, are straight lines through the origin. When the applied confining stress is less than the triaxial consolidation yield stress （i.e. pre-yield stress state）, undrained shear strength of undisturbed samples are larger than remolded samples due to the resistance of soil structure. While at post-yield state （the applied confining stress is larger than the triaxial consolidation yield stress）, strength envelope of the undisturbed sample lies among the remolded samples with different initial water contents. This difference is found to be caused by the difference in initial water content. The changing in water content and strength with confining stress for undisturbed sample at post-yield state behave like as a remolded sample at given initial water content. The compression behavior of undisturbed sample at post-yield state or remolded samples of different initial water contents can be well normalized by the void index proposed by Burland.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2009年第11期3297-3301,共5页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.50878050)
关键词
不扰动样
重塑样
不排水强度
初始含水率
undisturbed samples
remolded samples
undrained shear strength
initial water content
