| 引用本文: | 吴 浪,杨 帅,田玉凤,等.考虑冻土双向冻胀的含初始裂纹梯形渠道断裂力学分析[J].灌溉排水学报,2026,45(10):72-79. |
| Wu Lang,Yang Shuai,Tian Yufeng,et al.考虑冻土双向冻胀的含初始裂纹梯形渠道断裂力学分析[J].灌溉排水学报,2026,45(10):72-79. |
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| 摘要: |
| 【目的】研究寒区含初始裂纹梯形渠道混凝土衬砌在冻土双向冻胀作用下的断裂力学特性。【方法】基于渠道冻胀工程力学与线弹性断裂力学理论，建立了同时考虑截面弯矩与轴力影响的开裂判据，并引入双向冻胀系数ε，表征冻土法向与切向冻胀强度差异，构建了适用于梯形渠道的冻胀断裂力学模型。以甘肃省白银市某梯形渠道为原型，系统分析了ε对截面轴力、应力强度因子及合理板厚的影响。【结果】①双向冻胀系数对各截面应力强度因子的变化趋势影响较小，但对应力强度因子的大小具有显著作用，且ε越大，应力强度因子越高；②危险截面主要分布在距坡脚约35%~55%处。③随着ε增大，截面轴向压力绝对值减小，忽略双向冻胀效应将低估结构拉应力，影响结构安全。【结论】衬砌板合理厚度随ε增大近似线性增长，当ε=0.422时合理板厚为12 cm。为保证渠道安全运行，依据断裂力学理论合理选择板厚至关重要。 |
| 关键词: 渠道 冻胀 断裂力学 双向冻胀 应力强度因子 |
| DOI：10.13522/j.cnki.ggps.2026016 |
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| Fracture mechanics analysis of trapezoidal canal linings with pre-existing cracks under bidirectional frost heave in frozen soil |
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Wu Lang, Yang Shuai, Tian Yufeng, Xiao Min, Jiang Haoyuan, Li Hao
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1. School of Civil Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013, China;
2. Key Laboratory of Cryospheric Science and Frozen Soil Engineering, Northwest Institute of
Eco-environment and Resources, Lanzhou 730000, China
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| Abstract: |
| 【Objective】Concrete lining cracking caused by frost heave poses a major threat to the structural safety and serviceability of irrigation canals in cold regions. This study investigated the mechanical initiation and propagation of cracks in concrete linings of trapezoidal canals subjected to bidirectional frost heave in frozen soils.【Method】The study was based on frost-heave mechanics and linear elastic fracture mechanics. A cracking criterion incorporating the combined effects of sectional bending moment and axial force was established, with the difference in frost-heave intensity between the normal and tangential directions characterized by a bidirectional frost-heave coefficient (ε). A fracture-mechanics model for canal linings subjected to frost heave was developed and applied to a trapezoidal canal in Baiyin City, Gansu Province, to analyze the effect of ε on sectional axial force, stress intensity factors and the appropriate lining-slab thickness.【Result】①The bidirectional frost-heave coefficient did not significantly affect the variation in stress intensity factors across different sections of the canal but significantly affected their magnitudes, which increased with increasing ε. ②Both numerical modelling and experimental results indicated that the critical sections were mainly distributed at approximately 35%-55% of the distance from the slope toe. ③With increasing ε, the absolute value of the sectional axial compressive force decreased. Neglecting bidirectional frost heave underestimated the tensile stress in the lining and thereby compromising structural safety.【Conclusion】The appropriate lining-slab thickness increased linearly with increasing ε. When ε=0.422, the appropriate slab thickness was 12 cm. It is essential to consider fracture-mechanics-based criteria when determining lining thickness to ensure the safe operation of canals in cold regions. This study provides a theoretical basis and technical support for the design of frost-resistant concrete-lined canals in seasonally frozen regions. |
| Key words: canals frost heave fracture mechanics bidirectional frost heave stress intensity factor |
