李宗利, 姚希望, 张锐, 邵化建, 王正中. 考虑基土不均匀冻胀的梯形渠道混凝土衬砌弹性地基梁力学模型[J]. 农业工程学报, 2020, 36(21): 114-121. DOI: 10.11975/j.issn.1002-6819.2020.21.014
    引用本文: 李宗利, 姚希望, 张锐, 邵化建, 王正中. 考虑基土不均匀冻胀的梯形渠道混凝土衬砌弹性地基梁力学模型[J]. 农业工程学报, 2020, 36(21): 114-121. DOI: 10.11975/j.issn.1002-6819.2020.21.014
    Li Zongli, Yao Xiwang, Zhang Rui, Shao Huajian, Wang Zhengzhong. Frost heave mechanical model of concrete lining trapezoidal canal considering nonuniform frost heave of foundation soil based on elastic foundation beam theory[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2020, 36(21): 114-121. DOI: 10.11975/j.issn.1002-6819.2020.21.014
    Citation: Li Zongli, Yao Xiwang, Zhang Rui, Shao Huajian, Wang Zhengzhong. Frost heave mechanical model of concrete lining trapezoidal canal considering nonuniform frost heave of foundation soil based on elastic foundation beam theory[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2020, 36(21): 114-121. DOI: 10.11975/j.issn.1002-6819.2020.21.014

    考虑基土不均匀冻胀的梯形渠道混凝土衬砌弹性地基梁力学模型

    Frost heave mechanical model of concrete lining trapezoidal canal considering nonuniform frost heave of foundation soil based on elastic foundation beam theory

    • 摘要: 为了探究寒区高地下水位引起基土和衬砌板耦合非均匀变形对梯形渠道衬砌内力变化影响规律,该研究在前期提出的弹性地基梁模型基础上,将衬砌板与基土相互作用效应分解为基土不均匀自由冻胀位移、衬砌板受到冻土反作用产生的位移和边坡衬砌板坡脚约束产生的相对转动位移,从而建立了满足两端变形协调的弹性地基梁模型。以甘肃省高液限土壤,地下水位5 m 地区的边坡系数为1 的渠道为例,探究不同边坡衬砌板长度和不均匀冻胀基土之间的相互作用。结果表明,边坡衬砌板长度每增加1 m,冻胀反力最大值增大142%,弯矩最大值平均增大223%,弯矩最大值点会从原来的距坡脚1/3 左右处向坡脚偏移。以边坡衬砌板长度为4 m 为例,探究了基土均匀冻胀和不均匀冻胀对边坡衬砌板影响的差异,得出基土不均匀冻胀的冻胀反力最大值和弯矩最大值,分别比基土均匀冻胀大264%和170%。因此,在寒区高水位地区进行渠道抗冻胀衬砌设计时,宜按基土非均匀冻胀弹性地基梁模型计算。

       

      Abstract: In areas with high groundwater levels in cold regions, due to the different distances between the calculation points of the canal slope lining slab and the groundwater level, the frost heave of the foundation soil under the slope lining slab presents a different distribution from the canal top to the canal bottom. The slope lining slab has a large amount of frost heave in the bottom area of the canal, and a small amount of frost heave in the canal top area. To explore the effect of nonuniform frost heave of foundation soil caused by high groundwater level in cold areas on the frost heave of concrete lining trapezoidal cannal, the interaction effect between the lining slab and the foundation soil was disintegrated into the uneven free frost heave displacement of the foundation soil, the displacement produced by the reaction of the lining slab and frozen soil, and the relative rotational displacement of the slope lining slab produced by the restraint of the slope foot. Thus, an elastic foundation beam model that satisfied the coordination of deformation at both ends was established based on the elastic foundation beam model proposed earlier. Taking the canal with slope coefficient of 1 and groundwater level of 5 m as an example, this canal was surrounded by the high liquid limit soil in the Gansu Province. The interaction between the different lengths of slope lining slabs and the nonuniform frost heave foundation soil in the process of frost heave was explored. The results showed that for every 1-m increase in the length of the slope lining slab, the maximum value of frost heave reaction force at the slope foot increased by 142%, and the maximum value of bending moment averagely increased by 223%. Meanwhile, the position of the maximum value of the bending moment moved from the original one-third of the slope foot to the slope foot. Therefore, it was recommended that the cross section should better be designed as wide and shallow as possible in order to reduce the influence of nonuniform frost heave of the foundation soil caused by the groundwater level on the canal lining slabs. For trapezoidal canal with narrow and deep cross-sections, it was recommended to set joints within one-third to one-fifth of the length of the slope lining slab from the slope foot to release the frost heave force. The specific location should be comprehensively considered and determined according to the groundwater level, the length of the slope lining slab and the slope coefficient. Meanwhile, taking the slope lining slab length of 4 m as an example, the difference between the effects of nonuniform frost heave and uniform frost heave on the slope lining slab was explored, and maximum frost heave reaction force and maximum bending moments were 264% and 170% greater than the uniform frost heave of the foundation soil, respectively. Therefore, when designing the anti-freeze-heave canal lining slabs in the cold area with high groundwater, the calculation should be based on the nonuniform frost heave elastic foundation beam model. This study can guide the design of anti-frost heave of canal lining slabs in cold areas with high groundwater.

       

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