The canal is crucial for water diversion projects, but it is susceptible to frost damage. To address this, a two-layer composite geomembrane lining structure (TLCGLS) was proposed that regulates the interaction between canal lining and frozen soil. Model tests were conducted to investigate its anti-frost heave effectiveness. Considering the interaction among the lining, two-layer composite geomembranes (TLCGs), and frozen soil, a canal frost heave model with heat-water-mechanical coupling was developed. The influence of canal cross-section shapes and TLCGs arrangements on anti-frost heave performance and mechanism of TLCGLS were discussed. Results show that TLCGLS reduces uneven frost heave degree and compressive/tensile strains of the lining by 35%, 29%, and 28% respectively. During melting, it rapidly reduces frost heave, tangential deformation, and strain with minimal residual effects. TLCGLS demonstrates strong resetting ability and excellent anti-frost heave performance. It is particular suitable for arc-bottomed trapezoidal canals. However, excessive reduction in friction between TLCGs weakens arching effect of the bottom lining, increasing tensile stress and safety risks. TLCGLS with geomembrane-geotextile contact exhibits superior anti-frost heave performance, mitigating compressive stress by over 50% while meeting design requirements for tensile stress. These findings provide a theoretical basis and technical solution for mitigating frost damage in canals.

中文翻译：

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一种新型两层复合土工膜衬砌结构减轻寒冷地区运河冻害的模型试验和数值模拟


这条运河对于引水项目至关重要，但它容易受到霜冻的损害。为了解决这个问题，提出了一种两层复合土工膜衬砌结构 （TLCGLS），用于调节运河衬砌与冻土之间的相互作用。进行了模型测试以研究其抗冻胀效果。考虑衬砌、两层复合土工膜 （TLCG） 和冻土之间的相互作用，开发了热-水-机械耦合的运河冻胀模型。讨论了根管横截面形状和 TLCGs 布置对 TLCGLS 抗冻胀性能和机制的影响。结果表明，TLCGLS 将衬里的不均匀冻胀程度和压缩/拉伸应变分别降低了 35%、29% 和 28%。在熔化过程中，它可以迅速减少冻胀、切向变形和应变，同时将残余影响降至最低。TLCGLS 表现出强大的复位能力和优异的抗冻胀性能。它特别适用于弧形底部梯形根管。然而，TLCG 之间摩擦的过度减少削弱了底衬的拱形效果，增加了拉应力和安全风险。与土工膜-土工布接触的 TLCGLS 表现出卓越的抗冻胀性能，在满足拉伸应力设计要求的同时，将压应力减轻 50% 以上。这些发现为减轻渠道霜冻害提供了理论依据和技术解决方案。