摘要
【目的】明确高地下水位冻土区弧形底浅拱梯形渠道冻胀破坏机理并提出简捷、实用的抗冻胀设计方法。【方法】考虑此类渠道拱高明显小于断面整体深度的特殊性,基于Winkler假设提出衬砌体法向冻胀力计算方法。论证高地下水位渠道衬砌体微小刚性上抬位移对曲线形弧段切向冻结力的影响机制并提出切向冻结力计算方法。基于此构建高地下水位冻土区弧形底梯形渠道冻胀力学模型。【结果】以某弧形底梯形渠道为原型,对比分析不同渠底中心地下水位d对衬砌板截面内力及所受冻胀力的影响。结果表明,d越小则截面内力及冻胀力分布的横向差异越明显;z_(0)越大,截面内力及冻胀力分布受地下水补给条件的影响越小,与事实相符。充足的水分补给时间、补给来源以及冻胀力横向的不均匀、不同步是此类渠道易遭受冻胀破坏的主要原因。【结论】该模型可较好地反映此类渠道的冻胀受力特性,计算结果合理、可靠,可为高地下水位冻土区弧形底浅拱梯形渠道抗冻设计和相关研究提供参考。
【Objective】Frost heave is a hazard damaging canals constructed in frozen soils with shallow groundwater table.Taking trapezoidal canals with arc bottoms as an example,this paper investigated the mechanisms underlying the formation of frost heave and its dependance on groundwater table depth.【Method】The analysis was based on the Winkler assumption and that the height of the arc was much less than overall depth of the canal.We proposed a method to calculate the variation of normal force over the frost heave force,as well as the distribution of tangential freezing force over the curved segments of the canal linings.A mechanical model was constructed to analyze the damages caused by frost heave.【Result】The transverse difference in the distribution of the sectional internal force and the frost heave force both increased as the depth of groundwater table decreased.The effect of groundwater table depth on distribution of the sectional internal force and frost heave force decreased as the depth of the groundwater table increased.Adequate time and source for water recharge and transversely uneven distribution of frost heave force are the main cause of frost heave damage to the canals.【Conclusion】The proposed model describes the mechanical characteristic of the canals due the impact of frost heave reasonably well,and the calculated are accurate and reliable.The proposed method and results provide a tool to help design canals to improve the resistance against frost heave damages.
作者
肖旻
熊志豪
吴浪
崔浩
杨晓松
葛建锐
XIAO Min;XIONG Zhihao;WU Lang;CUI Hao;YANG Xiaosong;GE Jianrui(School of Civil Engineering,Jiangxi Science&Technology Normal University,Nanchang 330013,China;College of Water Conservancy and Construction Engineering,Tarim University,Alaer 843300,China;College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《灌溉排水学报》
CSCD
北大核心
2022年第7期104-110,共7页
Journal of Irrigation and Drainage
基金
国家重点研发计划重点专项项目(2017YFC0405100)
国家自然科学基金项目(U2003108,51641903,51869029)
江西科技师范大学博士科研启动基金项目(2019BSQD11)。
关键词
冻土工程
灌溉渠道
力学模型
弧底梯形
高地下水位
frost soil engineering
irrigation canals
mechanical model
trapezoidal canal with shallow arc-bottom
high groundwater level
