整体式U型混凝土渠道衬砌-冻土接触模型  

Lining-frozen soil contact model in an integral U-shaped concrete canal

作　　者：王玉宝[1,2] 吴浩兴 刘荣 白雅文 程森浩 张晨昊 周仁宇 WANG Yubao;WU Haoxing;LIU Rong;BAI Yawen;CHENG Senhao;ZHANG Chenhao;ZHOU Renyu(Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling 712100,China;Institute of Water Saving Agriculture in Arid Regions,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,杨凌712100 [2]西北农林科技大学旱区节水农业研究院,杨凌712100

出　　处：《农业工程学报》2023年第9期142-151,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2022YFD1900501)。

摘　　要：为探究渠道衬砌与冻土接触面间存在的冻结约束、相对滑动与分离等接触作用对渠道衬砌冻胀破坏的影响,该研究以整体式U型渠道冻胀破坏监测试验为原型,构建了考虑接触和不考虑接触两类渠道冻胀模型,结合现场试验结果评估模型的合理性,并分析衬砌的冻胀变形与受力变化过程。结果表明:相比于不考虑接触模型,考虑接触模型的模拟结果更符合现场试验情况。在边坡处,考虑接触模型的法向应力峰值与试验监测峰值接近,不考虑接触模型的法向应力峰值可达前两者的3.3倍。试验与考虑接触模型的渠底法向应力基本为0,而不考虑接触模型中则存在持续增大的拉应力。现场试验的衬砌-冻土接触面间存在渠底分离与渠坡相对滑动过程,因此需由考虑接触模型模拟分析该过程。在试验与考虑接触模型中,渠底处衬砌与基土由于发生分离而产生空隙,此后悬空衬砌与渠坡基土发生相对滑动,释放了冻胀基土对衬砌的挤压力。考虑接触模型中的相对滑动改变了衬砌应力的发展趋势,由不考虑接触模型的“增力”变为考虑接触模拟的“卸力”。与不考虑接触模型相比,考虑接触模型的衬砌上、下表面正应力峰值分别降低了903%和164%,下表面切向力峰值降低了248%。在渠道冻胀模型中考虑接触作用更加合理,研究可为寒区渠道防冻胀设计与结构优化提供参考。Uneven frozen heave can cause some damage to the canal lining structure,particularly in the frozen soil in the north cold region of China.The frost-heaving damage of canal lining is closely related to the lining-frozen soil contact action.Some relations of contact consist of the contact surface,such as the freezing constraint,and friction slip.The lining stress can also depend directly on the separate conditions.However,the current simulation of the lining-frozen soil contact is mostly focused on the steady state.It is still lacking in the experimental verification of the mechanical parts.Taking the integral U-shaped canal frost heaving damage experiment in the Hetao irrigation area as the prototype,this research aims to construct the canal frost heave model with/without the contact relationship.Finite element(FE)software ABAQUS was selected to simulate the frostheaving damage process of the model.Two models were evaluated to compare the experimentally monitored data from the subsoil temperature field,layered frost heave displacement,and soil stress.A systematic analysis was made to determine the stress state and damage mechanism of the canal lining.The experimental and simulation were integrated to clarify the influence of lining-frozen soil separation and sliding process on the frost-heaving damage of the canal.The results show that the simulation considering the contact model was more consistent with the field test conditions,compared with no contact.There were the basically same distributions of temperature field between the experiment and simulation with/without contact.Specifically,the simulated freezing depths of the shady and sunny slopes increased by 2.44%and 1.68%,respectively,whereas,the freezing depth of the canal bottom decreased by 4.26%,compared with the experimental.Small errors were found between the experimental and simulated subsoil and lining normal frost heave displacement.The consideration of contact posed a weak limiting effect on the canal slope subsoil freezing.The average relative errors

关 键 词：渠道 冻胀破坏 模型 衬砌-冻土接触 接触本构 

分 类 号：S277[农业科学—农业水土工程] TV698.26[农业科学—农业工程]