冻融循环作用下不同含水率灰土的细微观结构与宏观力学性能

Microstructure and Macro-mechanical Properties of Lime Soil with Different Moisture Contents Under Freeze-Thaw Cycle

为了探明素土和灰土在不同含水率时细微观结构与宏观力学性能受冻融循环的影响规律,开展了素土和灰土在不同含水率时的冻融循环试验、抗压强度试验和核磁共振试验。结果表明,素土和灰土抗压强度均随含水率的提高而降低;素土和灰土抗压强度在同一含水率时均随着冻融循环次数的增加而降低,冻融循环六次时降低率可达到12次时的80%左右;灰土T_(2)谱信号峰值大于素土,T_(2)谱信号峰值随着灰土比例的提高而增大;不同含水率时素土和灰土T_(2)谱面积在冻融循环次数由3次增大至6次的增长率均明显大于6次至12次。

In order to ascertain the effect law of microstructure and macro-mechanical properties of plain soil and lime soil affected by freeze-thaw cycles under different moisture contents,the freeze-thaw cycle tests,compressive strength tests and nuclear magnetic resonance tests were carried out for plain soil and lime soil at different moisture contents.The results show that the compressive strength of plain soil and lime soil decrease with increase of moisture content.The compressive strength of plain soil and lime soil decrease with increase of the number of freeze-thaw cycles at the same moisture content,the reduction rate at 6 freeze-thaw cycles can reach to about 80%of that at 12 freeze-thaw cycles.The peak value of T_(2)spectrum signal of lime soil is larger than that of plain soil,the peak value of T_(2)spectrum signal increase with lime to soil ratio.Under different moisture contents,the growth rates of T_(2)spectrum area of plain soil and lime soil when the freeze-thaw cycles increase from 3 times to 6 times are all obviously greater than that from 6 times to 12 times.