考虑土与板间摩擦力的两拼式U形复合衬砌渠道冻胀破坏力学模型

Frost Heaving Mechanics Model of Composite Lining U-shaped Canals Considering Interface Friction from Soil,Geo-membrane and Splicing Double Arc-plates

针对宁夏引黄灌区混凝土衬砌渠道冻胀破坏严重的现状,以小U形渠道为研究对象,建立了考虑摩擦力的两拼式U形复合衬砌渠道冻胀破坏力学模型,探讨土工膜混凝土复合衬砌体与渠基土之间的摩擦力对渠道衬砌板内力分布以及渠道抗冻胀的影响,并通过算例进行了对比验证。与刚性混凝土衬砌渠道相比,加入土工膜后,复合衬砌体产生了允许范围内的冻胀位移量,削弱了冻土对衬砌板的切向约束力,改善了衬砌体的受力状态,使冻胀量分布更加均匀,渠道冻胀力、冻结力减小,抗拉强度提高,抗冻胀能力有所增强。

In view of the serious situation that the concrete lining canals have been damaged by the frost heaving in the irrigation area of Ningxia,the mechanical model of frost heaving damage to the composite lining canal with splicing double arc-plates has been established.The internal force distribution and the anti-frost heaving effect of concrete lining have been investigated by considering the friction between the geo-membrane and channel soil.And the analysis procedure is explained by using an example.Compared with the rigid concrete lining canal,the tangential force of constraint of the lining canal is reduced by adding the compound geo-membrane,the stress condition of the lining structure is also improved because of a number of allowable displacements of frost heave,the distribution of the frost-heave capacity is more balanced,frost heaving force and frozen force decrease while tensile strength increases.So the anti-freeze bilge ability of concrete lining canal is enhanced.