Effect of strain rate on consolidation behavior of Ariake clay and selection of the suitable strain rate
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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 behavior of Ariake clay is investigated by the constant rate of strain (CRS) consolidation tests under different strain rates, and the suitable stain rate in CRS consolidation tests is discussed based on the comparison results of CRS consolidation tests and routine incremental loading (IL) consolidation tests. The test results show that the stress-strain curves of Ariake clay shift in a parallel manner to the right with the increase of the strain rate. The preconsolidation pressure (pc) increases by about 17% and the coefficient of consolidation (cv) in the virgin consolidation range increases by about 34% respectively with a tenfold increase in the strain rate. The values of pc and cv from CRS tests with a strain rate of 0.02%/min are comparable to those from IL tests. The average strain rate up to 90% of strain of 24 h in the virgin consolidation range of IL tests is close to 0.02%/min based on the calculation of average strain rates up to different strains in IL consolidation tests. It is suggested that the strain rate in CRS consolidation tests corresponding with the mean value of average strain rate up to 90% of strain of 24 h under different consolidation pressures in IL tests should be adopted.
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Keywords:
- strain rate /
- consolidation behavior /
- preconsolidation pressure /
- clay
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