不同初始孔隙水压力下混凝土动态力学特性

发布时间：2019-05-14 01:21

【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。
[Abstract]:In order to study the dynamic mechanical properties of concrete under different initial pore water pressures, the constant triaxial tests of concrete under different initial pore water pressure and different loading rates were carried out by using 10 MN large multifunctional hydraulic servo static and dynamic triaxial apparatus. The results show that the variation of pore water pressure in concrete can be divided into three stages: rapid change, slow change and stabilization under different confining pressures. At different strain rates, the peak stress of concrete increases with the increase of initial pore water pressure, and the effect of initial pore water pressure on the peak stress of concrete is increased by high strain rate. The initial pore water pressure improves the rate sensitivity of peak stress of concrete to a great extent. Under different initial pore water pressures, the peak stress of concrete increases with the increase of strain rate. Based on the experimental data and Weibull statistical theory model, the empirical rate constitutive equation of concrete under water environment is constructed, and the stress-strain curves of concrete under constant triaxial dynamic compression under different initial pore water pressure are described, and the fitting effect is good. It is proved that the model can be used to describe the full stress-strain curve and damage variation of concrete under different working conditions.
【作者单位】：三峡大学土木与建筑学院;
【基金】：国家自然科学基金资助项目(51279092) 三峡大学研究生科研创新基金资助项目(SDYC2016019)
【分类号】：TU528

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