纳米高性能混凝土+复合土工膜新型衬砌结构抗冻胀模拟

Simulation of Frost Heave Resistanceof the Nano High Performance Concrete plus Composite Geomembrane Structure

以位于西北旱地寒地区的某梯形混凝土水工灌溉渠道为背景,在概述渠道预制混凝土板、现浇混凝土等衬砌结构冻胀及裂缝等病害概况的基础上,引入复合土工膜及纳米高性能混凝土等新型防渗衬砌材料应用的可行性;复合土工膜具备较好的防渗性能和适应变形能力,而将纳米微粉掺入混凝土材料后能大幅提升其抗渗、抗冻胀性能。在这样分析的基础上借助有限元软件对所提出的“纳米高性能混凝土+复合土工膜”的新型衬砌结构在工程应用过程中对应的温度场、变形场、应力场等展开仿真模拟。结果表明,纳米高性能混凝土+复合土工膜衬砌的新型衬砌结构能时衬砌板冻胀力分布更加均匀,结构变形充分释放,法向及切向冻胀力取值明显减小,原衬砌结构所对应的冻胀破坏也得以控制。纳米高性能混凝土+复合土工膜衬砌新型衬砌结构型式可在中国西北旱寒地区水工渠道衬砌实践中推广应用。

Taking a trapezoidal concrete hydraulic irrigation channel located in the arid and cold region of Northwest China as the background, the feasibility of applying new anti-seepage lining materials such as composite geomembrane and nano high performance concrete is introduced on the basis of summarizing the frost swelling and cracks of the lining structures such as precast concrete slab and cast-in-place concrete in the channel. The composite geomembrane has good anti-seepage performance and deformation adaptability, while adding nano powder into concrete can greatly improve its impermeability and frost expansion resistance. On the basis of such analysis, the temperature field, deformation field and stress field of the proposed new lining structure of Nano High Performance Concrete plus Composite Geomembrane in the process of engineering application are simulated with the help of finite element software. The results show that the new lining structure of Nano High Performance Concrete plus Composite Geomembrane lining can distribute the frost heave force more uniform,fully release the structural deformation, significantly reduce the value of normal and tangential frost heave forces, and control the frost heave damage corresponding to the original lining structure. The new lining structure of can be popularized and applied in the practice of hydraulic channel lining in the arid and cold regions of Northwest China.