循环孔隙水压下混凝土常规三轴压缩损伤破坏特性分析

发布时间：2018-03-18 06:49

本文选题：常规三轴压缩试验　切入点：循环次数　出处：《实验力学》2015年06期 　论文类型：期刊论文

【摘要】：本文进行了孔隙水压不同循环次数(0次,10次,50次,100次和200次)以及不同应变速率下(10~(-5)/s,10~(-4)/s,10~(-3)/s和10~(-2)/s)混凝土常规三轴压缩试验,分析了混凝土峰值应变的变化规律、应力-应变曲线及损伤特性。结果表明:相同循环次数孔隙水压下,峰值应变随应变速率增加,整体呈现出增加的趋势;而相同应变速率下,峰值应变随孔隙水压循环次数的变化规律并不明显;在中低应变速率(10~(-5)~10~(-3)/s)下,混凝土的损伤变化受孔隙水压循环次数影响较大;当循环次数达到200次时,孔隙水压作用对混凝土产生较大的损伤。通过对循环孔隙水作用下混凝土动态损伤破坏机理的分析可知:混凝土的破坏过程实际上是内部裂纹不断形成、扩展、贯通,材料损伤不断产生、累积的过程;当损伤达到一定程度,混凝土发生宏观破坏,失去承载力。
[Abstract]:In this paper, the conventional triaxial compression tests of 10 cycles of pore water pressure (10 times, 10 times, 50 times, 100 times and 200 times) and different strain rates are carried out, and the variation of the peak strain of concrete is analyzed by using conventional triaxial compression tests of 10 / 10 / 10 / 10 / 4 / 10 / 10 / 10 / 10 / 10 / 3 / s and 10 / 10 / 2 / 2 / s of concrete. Stress-strain curves and damage characteristics. The results show that the peak strain increases with the increase of strain rate under the same cyclic times of pore water pressure, while at the same strain rate, the peak strain shows an increasing trend. The change of peak strain with the number of pore water pressure cycles is not obvious, and the damage change of concrete is greatly affected by the number of pore water pressure cycles when the number of cycles reaches 200 times under the medium and low strain rate of 10 ~ 10 ~ (-5) ~ 10 ~ (-3) ~ (-1 / s). Through the analysis of dynamic damage mechanism of concrete under the action of circulating pore water, it can be concluded that the failure process of concrete is actually the formation, expansion and penetration of internal cracks. Material damage is produced and accumulated continuously; when the damage reaches a certain degree, the macroscopic damage of concrete occurs and the bearing capacity is lost.
【作者单位】：三峡地区地质灾害与生态环境湖北省协同创新中心;三峡大学土木与建筑学院;
【基金】：国家自然科学基金项目(51279092) 三峡大学研究生科研创新基金项目(2014CX022);三峡大学2015硕士学位论文培优基金(2015PY017) 2014年湖北省协同创新中心研究生自主探索基金项目
【分类号】：TU528

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