刚性衬砌渠道不同纵缝削减冻胀效果的数值模拟

为了探明刚性衬砌渠道设置不同纵缝削减冻胀的机理及量化影响规律，提出削减冻胀的有效工程措施，该文利用有限元软件ADINA对坡脚处、1/3坡高处、宽底板的中心处分别设纵缝和不设纵缝的刚性衬砌渠道冻胀过程进行数值模拟，分析了温度场、变形场及应力场，特别研究了衬砌板的冻胀变形及其法向和切向冻胀力分布规律。通过对比分析表明：合理设置纵缝不仅能降低最大冻胀量61%，最大法向冻胀力45%，最大切向冻胀力32%，而且可使冻胀分布更加均匀，显著削减刚性衬砌渠道的冻胀破坏；削减冻胀的显著性依次是1/3坡高处设纵缝、坡脚处设纵缝、不设纵缝；但针对坡板较短、底板较宽情况在坡脚及底板中心处都设纵缝效果最好，降低最大冻胀量67%，最大法向冻胀力59%，最大切向冻胀力45%；数值模拟结果与工程实践基本一致。研究结果表明渠道冻胀的有限元数值模拟能够为季节冻土区渠道工程设计及力学计算提供参考和科学依据。

Computer simulation of frost heave for concrete lining canal with different longitudinal joints

In order to explore the mechanism and influencing rules of concrete lining canal with different longitudinal joints to weaken frost heave, furtherly provide some effective engineering measures of anti-frost heave, finite element software ADINA was applied to simulate canal frost heaving process when setting joints respectively in the toe, 1/3 of slope, center of wider base plate and not. The temperature field, deformation field and stress field were analyzed, especially the rules of frost heaving deformation, normal and tangential frost heaving force distribution were studied. The comparative analysis indicated that setting joints reasonably not only could reduce maximum heaving quantity 61%, maximum normal frost heaving force 45% and the tangential 32%, but also weaken frost heaving damage remarkably due to more uniform distribution of frost heaving force. The descending order of the significance of anti-frost heave was setting joints in the 1/3 slope, in the toe of slope and not. But for canals of shorter slope plate and wider base plate, setting joints both in the toe of slope and center of base plate could get the best effect, which reduced maximum frost heave quantity 67%, maximum normal force 59% and the tangential 45%. The result of computer simulation agreed well with engineering practice. The study shows that computer simulation of canal by finite element model can provide the reference and the scientific basis for canal engineering design and mechanics computation in seasonal frost region.