循环孔隙水压力作用对混凝土损伤特性研究

Study on damage characteristics of concrete subjected to cyclic pore water pressure

为研究混凝土在历经循环孔隙水压力后的损伤特性,利用10 MN大型多功能液压伺服静动力三轴仪,进行了常三轴混凝土动静力加载试验,基于能量分析的损伤本构模型改进,确定损伤变量,进行不同加载速率、不同循环孔隙水作用后的混凝土损伤特性的对比分析。研究结果表明:当饱和混凝土试件分别经历不同大小的循环孔隙水压力作用后,低应变速率下,损伤曲线分布较为分散,随着应变速率的增大损伤曲线越来越趋于集中。随着加载时应变速率的提高,损伤曲线的分布呈现出了一定的规律性:低应变速率下,随着循环孔隙水压力值的增大,产生相同值的损伤对应的应变越小;高应变速率下,产生相同值的损伤发生的应变越来越大。

In order to study the damage characteristics of concrete after cyclic pore water pressure,the static and dynamic loading test of the constant three axle concrete is carried out by using the 10 MN large multifunctional hydraulic servo static and dynamic three axis instrument,and the damage constitutive model based on energy analysis is improved to determine the damage variables,and to compare the damage characteristics of concrete after different loading rates and different cyclic pore water effects.The results show that when the saturated concrete samples undergo cyclic pore water pressure of different size at low strain rate,damage curve distribution is more dispersed,and damage curve tends to be more and more concentrated with the increase of strain rate.The distribution of damage curve shows certain regularity with the increase of strain rate under loading.The smaller the strain corresponding to the damage at the same value with the increase of cycle pore water pressure value at low strain rate,while the greater the strain corresponding to the damage at the same value with the increase of cycle pore water pressure value at high strain rate.