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| 考虑初始裂缝形态影响的混凝土细观水力劈裂研究 |
| Effect of Initial Crack Morphology on Meso-scale Hydraulic Fracturing Propagation in Concrete |
| 投稿时间：2025-04-10 修订日期：2025-09-11 |
| DOI： |
| 中文关键词: 初始裂缝 混凝土水力劈裂 细观尺度 内聚力单元 临界开裂水压 |
| 英文关键词: initial crack hydraulic fracturing of concrete meso-scale cohesive element critical cracking water pressure |
| 基金项目:国家自然科学(52209164)；国家重点研发计划资助项目(2017YFC405101) |
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| 中文摘要: |
| 因混凝土内部细观组成结构的随机性和力学性能差异会影响混凝土的宏观损伤破坏，为探究细观尺度下混凝土水力劈裂裂缝的扩展演化规律，考虑砂浆渗透系数随基体内部损伤演化的关系，考虑砂浆渗透系数随基体内部损伤演化的关系，建立了能够反映渗流-应力耦合作用的细观混凝土孔压内聚力模型，重点研究了细观尺度下初始裂缝倾角、初始裂缝长度、多条初始裂缝以及特殊形态初始裂缝对水力劈裂破坏的影响。研究结果表明,初始裂缝倾角的差异会导致主裂缝贯穿点发生不同程度的偏移；随着初始裂缝长度的增加，临界开裂水压降低，当裂缝长度由5mm增加至20mm时，临界开裂水压下降明显；相较于单条初始裂缝，多条初始裂缝的存在不仅劣化了混凝土的抗劈裂性能，还导致稳定扩展水压呈非周期性剧烈震荡；此外研究还得出特殊形态初始裂缝会影响细观尺度下裂缝与界面过渡区的连接，且易诱发更为复杂的开裂模式。初始裂缝形态对混凝土水力劈裂的临界开裂水压和裂缝扩展路径具有重要影响，研究可为混凝土结构水力劈裂破坏的预测与防治提供参考。 |
| 英文摘要: |
| Due to the inherent randomness of the internal meso-structure of concrete and the variation in mechanical properties, the macroscopic damage and failure behavior of concrete is influenced. To investigate the propagation and evolution laws of hydraulic fracturing cracks in concrete at the meso-scale,considering the relationship between the permeability coefficient of mortar and the internal damage evolution of the matrix, a meso-concrete pore pressure cohesion model that can reflect the seepage-stress coupling effect is established, this study examines the effects of initial crack dip angle, initial crack length, multiple initial cracks, and special initial cracks. The results indicate that the differences in the initial fracture dip angle can cause varying degrees of deviation in the main fracture penetration point. As the initial crack length increases, the critical cracking water pressure decreases. Specifically, when the crack length increases from 5mm to 20mm, the critical cracking water pressure drops significantly. Compared to a single initial crack, the presence e of multiple crack defects not only weakens the splitting resistance of concrete but also induces non-periodic violent oscillation in stable expansion water pressure. Furthermore, it is concluded that special initial cracks can affect the connection between cracks and the interfacial transition zone at the meso-scale, potentially leading to unique cracking patterns. The morphology of initial cracks significantly influences the critical cracking water pressure and crack propagation path of concrete hydraulic fracturing. The research provides reference for predicting and preventing hydraulic fracturing failure in concrete structures. |
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