U形复合衬砌渠道冻胀破坏力学模型研究

Research on Mechanics Models of Frost Heaving Damage of Composite Lining U-shape Canals

针对U形断面渠道,将复合土工膜和刚性混凝土衬砌体的摩擦力考虑在内,建立U形复合衬砌渠道的冻胀破坏力学模型,分别求出渠道坡板和底板内力表达式并对衬砌板的厚度进行了验算。对比刚性混凝土渠道,加入复合土工膜后,削减了冻土对衬砌板的切向约束力,改善了衬砌体本身的受力状态,使得冻胀量分布更加均匀,起到了防冻胀破坏的作用,揭示了冻胀破坏的机理。U形断面渠道水力条件更优,接近水力最佳断面,整体结构性更强,更能适应地基不均匀变形,更有利于渠道的防冻胀破坏。为U形复合衬砌渠道的防冻胀破坏技术提供了理论依据。

For the U-shape lining canal, the friction of the compound geomembrane and the concrete lining structure is taken into ac- count, the mechanics models of frost heaving damage of composite lining U-shape canal are established. The internal force of the canal slope lining plate and the canal bottom lining plate are solved and the thickness of the lining plates are checked. Compared with the concrete canal, the tangential force of constraint of the lining canal from the tjaele is cut down by adding the compound geomemhrane. The stress condition of the lining structure itself is improved. The distribution of the frost-heave capacity is more balanced. These have played an important role in anti-freezing expansion damage and have disclosed the mechanism of frost heaving damage. Compared with the trapezoidal canal, the lining U-shape canal has such advantages as better hydraulic conditions, better globality, better adapta- bility to nonaffine deformation of the foundation. All these are conducive to anti-freezing expansion damage. It serves as a theoretical basis for the technology of anti-freezing expansion damage of the compound lining canal.