有压水环境下循环荷载历史对饱和混凝土动态力学特性的影响

为研究有压水环境中循环荷载历史对混凝土动态力学性能的影响,对历经不同荷载循环次数(0、25、50、100次)的水饱和混凝土试件(在2 MPa围压水环境中)进行了不同应变速率(10-5、10-4、10-3、10-2/s)下的常规三轴静动态压缩试验,分析了混凝土材料的峰值应力、峰值应变、弹性模量、吸能能力等基本力学参数的变化规律和机理。结果表明:同一加载速率下,水饱和混凝土的峰值应力、弹性模量和吸能能力均随循环次数的增长呈现出先增大后减小的规律,并且峰值应力和吸能能力增减的转折点随着应变速率的提高而向荷载循环次数增大的方向平移,峰值应变整体上呈减小的趋势;相同荷载循环次数后,峰值应力、峰值应变和吸能能力随着加载速率的增大而逐渐增大,并且荷载循环次数越大,率效应越显著,弹性模量随着加载速率的增大而逐渐较小。

Influences of cyclic loading history to rate effect of water-saturated concrete under pressurized water environment

To investigate the influences of cyclic loading history to rate effect of water-saturated concrete under pressurized water environment,the conventional triaxial compression test was carried out in different strain rates (10-5/s、10-4/s、10-3/s、10-2/s)with the water-saturated concrete samples (in the water environment with 2MPa confining pressure)which had experienced different cyclic loading times(0、25、50、100 times),the change law and mechanism of the basic mechanical parameters such as peak stress,peak strain,elasticity modulus and energy absorption ability were analyzed.It was found that the peak stress,elasticity modulus and energy absorption ability of water-saturated concrete samples all increaseed at first and then decreaseed with the increasing times of cyclic loading,and the turning point of peak stress and energy absorption ability came close to the direction that cyclic loading times became bigger with strain rate increasing,but the peak strain decreased generally.The peak stress,elasticity modulus and energy absorption ability of the concrete samples which experienced same cyclic loading times all increased with the strain rates increasing and the rate effect was more conspicuous with cyclic loading times increasing,the elasticity modulus showed the change law on the contrary.