| 王乾峰,刘云贺*,彭刚.有压水环境中的混凝土动态抗压性能试验研究[J].实验力学,2017,32(3):385~396 |
| 有压水环境中的混凝土动态抗压性能试验研究 |
| Experimental Study of Dynamic Compression Properties of Concrete Subjected to Water Pressure |
| 投稿时间：2016-05-22 修订日期：2016-08-14 |
| DOI：10.7520/1001-4888-16-099 |
| 中文关键词: 混凝土 水压力 应力应变曲线 动态性能 本构关系 |
| 英文关键词:concrete water pressure stress-strain curve dynamic property constitutive relation |
| 基金项目:国家自然科学基金项目(51279092)；水利部公益性行业科研专项(201501034-03)资助 |
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| 中文摘要: |
| 对有压水环境中的混凝土进行了不同应变速率下的动态压缩试验研究,获得了水压为0~10MPa时的混凝土含水量特征以及不同应变速率下的应力应变曲线。试验结果表明：应变速率不高于10-3/s时,混凝土的应力应变曲线与干燥混凝土的相似,受力状态如同单轴加载；在应变速率为10-2/s时,其应力应变曲线的后半支随水压力增加而提高,与三轴受力状态类似,水压力对混凝土形成了围压效应。混凝土的强度及其动态增强因子随应变速率呈非线性增加趋势,水压力越高则增长速度越快。强度压力增强因子随水压力的变化趋势在不同应变速率下存在差异。在慢速加载时,强度压力增强因子变化幅度为10%,而快速加载时,其随水压力提高而增加,且显著高于慢速加载时的情况。在深入研究混凝土强度动态增强因子和压力增强因子的基础上,构建了有压水环境中混凝土的经验本构模型。该模型考虑了水压力和应变速率共同作用对混凝土强度的影响,与试验数据吻合较好。结合混凝土的含水量特征,进一步分析了不同应变速率下孔隙水对其力学性能影响的作用机理,分析表明含水量不同导致了粘滞应力和超孔隙水压力的差异,从而引起混凝土强度的非线性增长。 |
| 英文摘要: |
| Dynamic compression experimental was carried out under different strain rates for concrete subjected to water pressure (0-10MPa), moisture content characteristics of concrete subjected to different water pressure and stress-strain curve under different strain rates were obtained. Experimental results show that when strain rate is not higher than 10-3/s, its stress-strain curve is similar to that of dry concrete, its stress state is similar to that of uniaxially loaded concrete. But when strain rate is 10-2/s, the post-peak stress-strain curve rises with the increase of water pressure, which is similar to stress state of tri-axially loaded concrete. Water pressure forms confining pressure effect on concrete. The strength and its dynamic increase factor of concrete nonlinearly increase with the increase of strain rate, the higher the water pressure is, the faster the growth rate. The variation of strength pressure increase factor (PIF) along with water pressure is different at different strain rate. Under slow loading condition, the amplitude variation of strength (PIF) is 10%, while under rapid loading condition, the amplitude increases with the increase of water pressure, and is significantly higher than the that in slow loading. Based on deep study of the strength dynamic increase factor and the pressure increase factor of concrete, an empirical constitutive model of concrete subjected to water pressure was constructed. In this model, the combined effect of water pressure and strain rate on concrete strength is considered, and the experimental data are in good agreement with the experimental data. Combining concrete water content characteristics, the mechanism of the effect of pore water on mechanical properties at different strain rates was further investigated. The authors consider that the difference of water content may the different viscous stress and the different excess pore water pressure, which leads to the nonlinear growth of concrete strength. |
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