中文摘要：

为研究不同初始孔隙水压力下混凝土动态力学特性,利用10 MN大型多功能液压伺服静动力三轴仪进行不同初始孔隙水压与不同加载速率下的混凝土常三轴试验。结果表明：不同围压下,混凝土内部孔隙水压的变化规律可分为迅速变化、缓慢变化和趋于稳定3个阶段。不同应变速率下,混凝土峰值应力随初始孔隙水压的增大逐渐增大,高应变速率提高了初始孔隙水压力对混凝土峰值应力的影响;初始孔隙水压力在较大程度上提高了混凝土峰值应力的率敏感性。不同初始孔隙水压力下,混凝土峰值应力随应变速率的提高逐渐增加。依据试验数据,基于Weibull统计理论模型构建了混凝土水环境下的经验率型本构方程,对不同初始孔隙水压下混凝土常三轴动态压缩应力-应变曲线进行描述,拟合效果良好。这证明所建模型可用来描述不同工况下混凝土应力-应变全曲线及损伤变化规律。

英文摘要：

The concrete samples under different initial pore water pressures were tested with different strain rates by a 10 MN large multifunctional hydraulic servo static and dynamic triaxial test equipment. The testing results show that： under confining pressure,changes of internal pore-water pressure can be divided into three phases： rapid,slow and stabilizing phases. Under the conditions of different strain rates,the peak stress of concrete increases gradually along with the increase of the initial pore water pressure and a high strain rate improves the influence of the initial pore water pressures on the peak stress of concrete; and under different initial pore water pressures,the peak stress of concrete increases with the increase of the strain rate. According to the testing data,based on Weibull statistical theory,a rate-dependent constitutive model for concrete is developed. The stress-strain curves of concrete with different pore water pressures under the confining water pressure are described by the model established,and the fitting results are good. The model can be used to describe the stress-strain curves and the damage of concrete under different working conditions.