Experimental Study on Micro Deformation Characteristics of Remolded Saturated Cohesive Soil at Different Loading Rates
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摘要: 对具有相同初始状态的饱和重塑黏性土采用不同加载速率进行固结,并在不同加载阶段对试样进行核磁共振测量,通过定性分析横向驰豫时间T2分布或T2谱面积变化与孔隙的关系,研究饱和重塑黏性土的变形微细观响应。结果表明:饱和重塑黏性土的固结初始阶段的T2谱由两个峰组成,随着加载固结的进行,大孔径孔隙逐渐闭合成小孔径孔隙,最终的T2谱形态都是单峰;加载较快土样在加载初期,受排水滞后的影响,其T2曲线谱的变化趋势不明显,恒载足够长时间后,无论加载速率快慢,土样的T2曲线谱最终形态极为相似,说明加载速率只对土样的中间状态产生影响,最终状态由试样初始状态决定。Abstract: The remolded saturated cohesive soil with the same initial state was consolidated at different loading rates, and the specimens were measured by nuclear magnetic resonance (NMR) in different loading stages. And then the relation of transverse relaxation time T2 distribution or T2 spectrum area change with porosity was qualitatively analyzed to study its microscopic response of deformation.The results showed that the T2 spectrum of saturated remolded cohesive soil in the initial stage of consolidation was consisted of two peaks. With the development of consolidation, the large pores gradually closed to small pores, and the final T2 spectrum turned out to be a single peak; for faster loading soil specimens influenced by lagging of drainage at the beginning of loading,the change trend of the T2 spectrum was not obvious.And after a long time of constant loading, the final shape for the T2 spectrum of the soil specimens was very similar regardless of the loading rate.It indicated that the loading rate only influenced the intermediate state of the soil specimens, the final state was dominated by the initial state of the specimens.
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