孔隙水压循环次数对混凝土损伤影响

发布时间：2018-03-15 09:35

本文选题：孔隙水循环次数　切入点：常三轴受压　出处：《水利水运工程学报》2016年06期 　论文类型：期刊论文

【摘要】：历经不同孔隙水压循环次数(0,10,50和200次)后,进行了中低应变速率(10-4/s)下混凝土常三轴受压损伤特性试验研究,分析其峰值应力、应变和弹性模量等基本力学参数随孔隙水循环次数变化的关系。同时依据受压切线模量的退化定义了损伤变量,得到应力水平比-损伤曲线,对混凝土损伤特性进行了研究。结果表明:1历经不同孔隙水循环后,混凝土常三轴受压峰值应力和应变随循环次数的增加呈指函数增加的趋势;弹性模量随循环次数的增加呈幂函数减小趋势并逐渐趋于平缓。2历经不同孔隙水循环次数后,混凝土的损伤发展速度整体上均大于0次循环,且随着循环次数的增加损伤速度逐渐降低。3通过应力水平比-损伤曲线,将混凝土损伤演化过程分为3阶段:损伤起始阶段、损伤发展阶段和损伤失稳阶段,同时依据所求损伤变量数据,拟合构建了损伤随应力水平比的演化方程。4依据损伤3个发展阶段定义了损伤界点,分析了损伤界点和损伤3阶段的应力水平区间长度随不同循环孔隙水压次数的变化。分析表明,随孔隙水压循环次数的增加,损伤界点对应的应力水平先增后减。
[Abstract]:After different pore water pressure cycles (50 and 200 times), the damage characteristics of concrete under constant triaxial compression at low and low strain rates (10-4 / s) were studied and its peak stress was analyzed. The relationship between the basic mechanical parameters such as strain and elastic modulus and the number of cycles of pore water is discussed. The damage variable is defined according to the degradation of compressive tangent modulus, and the stress level ratio to damage curve is obtained. The damage characteristics of concrete are studied. The results show that the peak stress and strain of concrete under constant triaxial compression increase with the increase of cyclic times, and the results show that the peak stress and strain of concrete under constant triaxial compression increase with the increase of cyclic times after different pore water cycles. The modulus of elasticity decreases with the increase of cycle times and tends to be flat. 2. After different pore water cycles, the damage development speed of concrete is all larger than 0 cycles as a whole. The damage evolution process of concrete is divided into three stages: damage initiation stage, damage development stage and damage instability stage through stress level ratio damage curve. At the same time, according to the data of damage variables, the evolution equation of damage to stress level ratio is constructed. 4. The damage boundary points are defined according to the three stages of damage development. The variation of stress level interval length of damage boundary point and damage three stage with different cyclic pore water pressure times is analyzed. It is shown that the stress level corresponding to damage boundary point increases first and then decreases with the increase of pore water pressure cycle times.
【作者单位】：三峡大学土木与建筑学院;长江科学院水利部岩土力学与工程重点实验室;
【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项目(2014CX022);三峡大学培优基金资助项目(2016PY026) 2014年湖北省协同创新中心研究生自主探索基金项目
【分类号】：TU528

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