有明黏土固结特性的应变率效应和应变率取值研究

发布时间：2018-11-13 12:49

【摘要】：通过不同应变率下的恒应变速率(CRS,Constant Rate of Strain)固结试验研究了应变率对有明黏土固结特性的影响,通过对比CRS固结试验和常规分级加荷(IL,Incremental Loading)固结试验的结果,探讨了CRS固结试验中应变率的取值问题。试验结果表明随着应变率的增大,有明黏土的应力应变曲线向右平行偏移,应变率增大10倍时,先期固结压力(pc)约增长17%,正常固结阶段的固结系数(cv)约增长34%;当应变率为0.02%/min时,CRS固结试验得到的pc和cv值与IL固结试验得到的值基本一致;通过计算IL固结试验中不同应变量时的平均应变率,发现在正常固结阶段,IL固结试验中达到90%的24h应变量时的平均应变率接近于0.02%/min,建议CRS固结试验中采用的应变率可取为IL固结试验中每级固结压力下达到90%的24 h应变量时的平均应变率的平均值。
[Abstract]:The effect of strain rate on the consolidation characteristics of open clay was studied by constant strain rate (CRS,Constant Rate of Strain) consolidation tests at different strain rates. The results of CRS consolidation test and conventional graded loading (IL,Incremental Loading) consolidation test were compared. The value of strain rate in CRS consolidation test is discussed. The experimental results show that with the increase of strain rate, the stress-strain curve of open clay deviates to the right, and when the strain rate increases by 10 times, the (pc) of preconsolidation pressure increases by about 17. The consolidation coefficient (cv) of normal consolidation stage increased about 34%. When the strain rate is 0.02%/min, the values of pc and cv obtained by CRS consolidation test are basically the same as those obtained by IL consolidation test. By calculating the average strain rate of different strain variables in the IL consolidation test, it is found that in the normal consolidation stage, the average strain rate of 90% 24 h strain in the IL consolidation test is close to 0.02% / min. It is suggested that the strain rate used in the CRS consolidation test can be taken as the average strain rate of 24 h at 90% of the consolidation pressure per stage in the IL consolidation test.
【作者单位】：天津大学建筑工程学院;天津大学滨海土木工程结构与安全教育部重点实验室;
【基金】：国家自然科学基金项目(51509181) 天津市应用基础与前沿技术研究计划(15JCQNJC43800)
【分类号】：TU442

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