A series of triaxial compression tests for frozen clay were performed by KoDCGF （freezing with non-uniform temperature under loading after K0 consolidation） method and GFC （freezing with non-uniform temperature wit...A series of triaxial compression tests for frozen clay were performed by KoDCGF （freezing with non-uniform temperature under loading after K0 consolidation） method and GFC （freezing with non-uniform temperature without experiencing Ko consolidation） method at various confining pressures and thermal gradients. The experimental results indicate that the triaxial compression strength for frozen clay in KoDCGF test increases with the increase of confining pressure, but it decreases as the confining pressure increases further in GFC test. In other words, the compression strength for frozen clay with identical confining pressure decreases with the increase in thermal gradient both in KoDCGF test and GFC test. The strength of frozen clay in KoDCGF test is dependent of pore ice strength, soil particle strength and interaction between soil skeleton and pore ice. The decrease of water content and distance between soil particles leads to the decrease of pore size and the increase of contact area between particles in KoDCGF test, which further results in a higher compression strength than that in GFC test. The compression strength for frozen clay with thermal gradient can be descried by strength for frozen clay with a uniform temperature identical to the temperature at the height of specimen where the maximum tensile stress appears.展开更多
文摘针对变压器油运行过程中受外界因素影响而老化导致性能下降的问题,基于静电吸附原理,利用Ansoft Maxwell有限元仿真软件对“波浪”形曲面极板构造梯度非均匀电场,对变压器油中电中性杂质和带电杂质在梯度非均匀电场中的运动规律及模式进行了探究,进而研制了静电吸附净油反应器;在此基础上,设计了正交试验方案以检验该静电吸附净油反应器对油品品质的提升效果,并优化了净油反应器的工作条件。结果表明,该静电吸附净油反应器的最优工作条件为:电压12 kV、温度45℃、流速0.1 m s;经该反应器净化处理后,变压器油的介质损耗因数由0.04258降至0.00376,说明研制的净油反应器可有效提升老化变压器油的品质。
基金Project(50534040) supported by the National Natural Science Foundation of ChinaProject(20110491489) supported by China Postdoctoral Science FoundationProject(2011QNA03) supported by Fundamental Research Funds for the Central Universities of China
文摘A series of triaxial compression tests for frozen clay were performed by KoDCGF （freezing with non-uniform temperature under loading after K0 consolidation） method and GFC （freezing with non-uniform temperature without experiencing Ko consolidation） method at various confining pressures and thermal gradients. The experimental results indicate that the triaxial compression strength for frozen clay in KoDCGF test increases with the increase of confining pressure, but it decreases as the confining pressure increases further in GFC test. In other words, the compression strength for frozen clay with identical confining pressure decreases with the increase in thermal gradient both in KoDCGF test and GFC test. The strength of frozen clay in KoDCGF test is dependent of pore ice strength, soil particle strength and interaction between soil skeleton and pore ice. The decrease of water content and distance between soil particles leads to the decrease of pore size and the increase of contact area between particles in KoDCGF test, which further results in a higher compression strength than that in GFC test. The compression strength for frozen clay with thermal gradient can be descried by strength for frozen clay with a uniform temperature identical to the temperature at the height of specimen where the maximum tensile stress appears.
