钱鹏, 徐千军. 含裂纹混凝土的三维渗透性分析[J]. 工程力学, 2017, 34(7): 195-202. DOI: 10.6052/j.issn.1000-4750.2016.02.0114
引用本文: 钱鹏, 徐千军. 含裂纹混凝土的三维渗透性分析[J]. 工程力学, 2017, 34(7): 195-202. DOI: 10.6052/j.issn.1000-4750.2016.02.0114
QIAN Peng, XU Qian-jun. THREE-DIMENSIONAL ANALYSIS OF PERMEABILITY OF CONCRETE WITH CRACKS[J]. Engineering Mechanics, 2017, 34(7): 195-202. DOI: 10.6052/j.issn.1000-4750.2016.02.0114
Citation: QIAN Peng, XU Qian-jun. THREE-DIMENSIONAL ANALYSIS OF PERMEABILITY OF CONCRETE WITH CRACKS[J]. Engineering Mechanics, 2017, 34(7): 195-202. DOI: 10.6052/j.issn.1000-4750.2016.02.0114

含裂纹混凝土的三维渗透性分析

THREE-DIMENSIONAL ANALYSIS OF PERMEABILITY OF CONCRETE WITH CRACKS

  • 摘要: 该文假设含裂纹的混凝土材料是由孔隙基体和裂纹组成的二相复合材料,基于相互作用直推法(IDD)给出了三维周期裂纹渗透性的表达式。基于单元嵌入技术和弹性比拟的数值模拟新方法,解决了三维细观连续有限元实体模型的建模和网格划分问题,实现了含混凝土裂纹的三维渗透模拟。假设裂纹为圆盘状,引入周期性的概念并提出三维周期裂纹结构模型,分析裂纹直径、裂纹周期、裂纹倾角和裂纹间距等因素对整体等效渗透性能的影响。将得到的数值解和IDD理论解进行对比分析,结果表明:在裂纹密度较低时,数值解和理论解吻合得很好,但随着裂纹密度的增大,二者之间的误差逐渐增大;当裂纹趋于连通时,IDD解低估了裂纹之间的近场相互作用而偏离数值解;裂纹接近连通时,整体等效渗透率与裂纹密度呈对数关系,可用渐进对数表达式准确描述。

     

    Abstract: Concrete with cracks is considered to be a two-phase composite material with a porous matrix and cracks. The interaction direct derivative (IDD) expression was used to estimate the effective permeability of periodic crack model. The conventional seepage numerical analysis method associated with continuous solid elements has some difficulties in mesh coordination, so a new method which combines embedded element technique with elastic analogy was developed to solve this problem. Based on the assumption of penny cracks, a model with three dimensional periodic microstructures was carried out to represent the geometric arrangement of cracks, and the effect of different geometric factors, namely crack diameter, crack density, structure periodicity, crack inclination, and space interval, were studied. The numerical result derived from the new method, was compared with the theoretical solution from IDD. The results reveal that the IDD-derived solution is suitable for low crack density, but it starts to underestimate the finite element results at higher crack density, especially when cracks are nearly touching. During their approach to each other, the effective permeability can be described by an asymptotic logarithmic expression.

     

/

返回文章
返回