高地下水水位冻土区梯形渠道衬砌冻胀破坏断裂力学模型  

Fracture mechanics model for frost heave-induced cracking of trapezoidal canal lining in frozen soil area with high groundwater table

作　　者：吴浪[1,2] 肖旻 席琛[1,2] 崔浩 杨晓松[3] 葛建锐 WU Lang;XIAO Min;XI Chen;CUI Hao;YANG Xiaosong;GE Jianrui(School of Civil Engineering,Jiangxi Science&Technology Normal University,Nanchang 330013,China;Disaster Prevention and Mitigation Engineering Technology Research Base of Jiangxi Association for Science and Technology Think Tank,Nanchang 330013,China;College of Hydraulic and Architectural Engineering,Tarim University,Alaer 843300,China;College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China.)

机构地区：[1]江西科技师范大学土木工程学院,江西南昌330013 [2]江西科技师范大学江西省科协智库防灾减灾工程技术研究基地,江西南昌330013 [3]塔里木大学水利与建筑工程学院,新疆阿拉尔843300 [4]兰州理工大学能源与动力工程学院,甘肃兰州730050

出　　处：《水资源与水工程学报》2024年第5期148-154,163,共8页Journal of Water Resources and Water Engineering

基　　金：国家重点研发计划“水资源高效开放利用”重点专项(2017YFC0405100);新疆生产建设兵团一师横向项目(SWJ2022KT23);国家自然科学基金项目(51641903、51869029);江西省教育厅科技项目(GJJ190621);江西科技师范大学博士科研启动基金项目(2019BSQD11)。

摘　　要：冻胀荷载作用下初始裂纹的形成、扩展导致衬砌结构的断裂是寒区衬砌渠道冻害的主要原因之一。在已有研究基础上,综合考虑地下水水位影响的梯形渠道冻胀力学分析方法及线弹性断裂力学理论,提出高地下水水位梯形渠道冻胀断裂力学分析框架。该模型将衬砌结构表面初始裂纹的失稳扩展及开裂破坏简化为Ⅰ型断裂力学问题,并提出应力强度因子与危险截面位置的计算方法。以塔里木灌区某梯形渠道为原型分析地下水埋深w对衬砌各截面应力强度因子K_(FⅠ)(x)及合理板厚d r的影响规律。结果表明:地下水补给条件对K_(FⅠ)(x)的大小影响显著;当w减小时,K_(FⅠ)(x)呈非线性增大,此时渠道冻害风险也增大,与事实相符。地下水埋深越浅,保证结构安全所需衬砌板的合理厚度d r越大;当地下水埋深为3.0 m时,建议使用的合理板厚为9.0 cm。研究结果可为寒区渠道的抗冻胀设计提供科学依据。The generation and propagation of initial cracks induced by frost heave loads result in the fracture of lining structures,which is a primary factor contributing to the occurrence of frost heave damage in canals located in cold regions.Based on existing research,a frost-heaving fracture mechanics model for concrete lining of trapezoid canals in frozen soil areas with high groundwater table is developed by integrating the analysis method of frost-heaving mechanics with the theory of linear elastic fracture mechanics.The proposed model reduces the complex process of initial crack propagation and fracture failure of the lining structure to a simplified type I fracture mechanics problem,so as to obtain a determination method for stress intensity factor and vulnerable sections.Taking a canal in Tarim Irrigation District as an example,the effects of different groundwater depth w on the distribution of stress intensity factor K_(FⅠ)(x)and reasonable lining plate thickness d r of the lining sections were analyzed.The results show that the magnitude of stress intensity factor is significantly influenced by groundwater recharge conditions.The decrease in w leads to a nonlinear increase in the magnitude of K_(FⅠ)(x),thereby amplifying the vulnerability of canal linings to frost heave-induced cracking,which is consistent with engineering practices.As w decreases,the reasonable lining plate thickness d r increases.When the groundwater table w is at a depth of 3.0 m,it is recommended to use a plate thickness of 9.0 cm.The study can provide valuable insights for the design of frost-heaving resistant trapezoidal canals.

关 键 词：梯形渠道 冻土 冻胀 断裂力学模型 高地下水位 非线性分布 

分 类 号：S277[农业科学—农业水土工程] TV67[农业科学—农业工程]