考虑冻胀反力系数动态变化的U形渠道弹性地基梁模型

Elastic Foundation Beam Model of U-shaped Canal Considering Dynamic Change of Frost Heave Reaction Coefficient

为了客观反映寒旱区渠道冻土和衬砌板间相互作用随土体温度的变化情况,利用冻土中土体和冰的体积含量、弹性模量、泊松比等地基特性与土体温度的关系,推导出随土体温度动态变化的冻胀反力系数表达式,建立考虑冻胀反力系数动态变化的U形混凝土衬砌冻胀力学模型,并应用于某两拼式U形渠道。通过与现场观测结果和已有研究结果对比可知,建立的冻胀反力系数计算方法是合理可靠的,模型计算的冻胀量、冻胀反力及衬砌结构内力等分布规律与现场观测结果吻合较好,计算结果偏小,与渠道实际冻胀状况更为相符。冻胀反力系数的变化体现出渠道不同时刻、不同位置的冻胀效应差异,突破了已有研究中仅获取冻胀效应最大值的弊端。

In order to objectively reflect the change of interaction between frozen soil and lining plate with soil temperature in the cold and arid areas,the relationship between soil temperature and foundation characteristics such as soil and ice volume content,elastic modulus and Poisson’s ratio was used to derive the expression of frost heave reaction coefficient dynamically changing with soil temperature,and a U-shaped concrete lining frost heave mechanics model considering the dynamic change of frost heaving reaction coefficient was established and applied to a two-piece U-shaped canal.By comparing the field observation results and the existing research results,it can be seen that the established calculation method of frost heave reaction coefficient is reasonable and reliable.The distributions of frost heave,frost heave reaction force and internal force of lining structure calculated by the model are in good agreement with the field observation results,and the calculation results are smaller and more consistent with the actual frost heave condition of the canal.The change of frost heave reaction coefficient reflects the difference of frost heave effect at different times and positions of the canal,which breaks through the drawback of obtaining only the maximum value of frost heave effect in the existing research.