干旱区生态环境知识资源中心(Arid): 基于弹性薄层接触模型研究衬砌渠道双膜防冻胀布设

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	基于弹性薄层接触模型研究衬砌渠道双膜防冻胀布设
其他题名	Double membranes cushion layout for preventing frost heave damage based on elastic thin contact model
	王羿; 王正中; 刘铨鸿; 刘月
来源期刊	农业工程学报
ISSN	1002-6819
出版年	2019
卷号	35 期号:12 页码:133-141
中文摘要	渠道衬砌下双膜防渗层可解除渠基土冻结力,释放衬砌结构位移以适应不均匀冻胀,但会影响衬砌结构的刚度与稳定性。为研究最佳双膜防渗层布设形式及其适应性,考虑双膜防渗层接触本构及衬砌结构与渠基土的相互作用,依据基土水热力三场耦合理论建立了寒区衬砌渠道的冻胀模型,通过数值模拟仿真分析了不同断面及不同双膜防渗层布设形式的弧底梯形渠道衬砌的冻胀受力与变位。结果表明:宽浅断面渠道采用双膜衬砌结构时,膜间摩擦力过小造成刚度和稳定性严重降低以及衬砌拉应力增加。适当的膜间摩擦力可以解除部分冻结约束,调整局部不均匀冻胀,而且发挥弧底反拱作用不产生拉应力。采用PE膜与无纺布作为层间接触的双膜衬砌结构,冻胀位移方差减小25%,同时整体位移增加不超过0.2 cm,削减冻胀应力50%以上。在不显著降低结构整体稳定性前提下,其整体刚度和结构强度提高程度最大,故同时适用于窄深渠道和宽浅渠道。研究为寒区衬砌渠道中双膜防渗层的合理布设提供科学依据。
英文摘要	Water delivery canals play an important role in highly efficient water use in arid and semi-arid regions in China. Those regions mostly belong to cold region widely distributed with seasonal frozen soils. Thus, canal lining is susceptible to frost damage because of the heave of freezing soil and the adfreezing constraint between foundation and lining. Double geo-membranes between lining and foundation soil have an advantage in relieving adfreezing strength and adjusting lining displacement to adapt nonuniform frost heave but reduce the stiffness and stability of lining structure. To find the best layout of double geo-membranes and quantitative analysis on the adaptation of the double geo-membranes, a heat-moisture-stress coupling model of frost heave for arc bottom trapezoidal canal was established by finite element method. A bilinear interaction model between layers of cushion was considered by thin elastic layer element, of which the friction force was expressed as reaction force relating to its shear stiffness. A total of 3 different layout forms of composite cushion (membrane-membrane, membrane-fabric and fabric-fabric) were simulated by various shear stiffness parameters. The lining stress and deformation were compared by different canal sections and layout forms of double membranes cushion under lining. The result showed that: 1) For narrow and deep lined canals, the smaller the friction between membranes would result in the more uniform frost heave but the worse overall structure stability. While for wide and shallow canals, it was disadvantageous for neither frost heave uniformity nor overall stability when reducing the friction between membranes. Hence considering the requirements of frost heave uniformity and stability, the membrane-fabric form was suitable for both narrow and deep lined canals and wide and shallow lined canals. 2) The arch structure at the bottom of canal had an arch effect that could increase the axial compressive force along lining when bearing the heave force at the lower surface of lining. But as decreasing friction by double membranes, the arch effect was weaken, causing the extra tensile stress in the slope of canal lining. Therefore, considering the requirements of structure strength, the membrane-fabric and fabric-fabric form was suitable for anti-frost damage of canal lining. Double membranes cushion with less adfreezing strength such as membrane-membrane and membrane-fabric combinations could relieve the freezing constraint and adjust lining uneven frost heave deformation, but may lead to large displacement and damage tensile stress as a result of the release of arch effect at the bottom of the canal. Therefore, double membranes cushion with some small friction could not ensure the safety of strength and stiffness of lining structure. In addition, proper adfreezing strength was helpful in adjusting uneven frost heave by partly slip and limiting overall deformation. Furthermore, the arch effect should be rationally utilized to produce compressive stress along lining. In consequence, when membrane-fabric was used as interface between membranes, the displacement variance of lining decreased by 25% and the frost heave stress reduced by more the 50%, while the overall displacement increased by 0.2 cm or less. This double membranes form, which was suitable for narrow and deep canals as well as wide and shallow canals, could meet the requirements of strength, stiffness and stability for lining structure, and could improve the adaptive ability for frost heave damage. The results could provide information for selecting reasonable layout of double membranes cushion lining canals in cold region.
中文关键词	渠道 ; 膜 ; 防冻 ; 冻胀破坏 ; 双膜防渗层 ; 水热力耦合 ; 冻胀模型 ; 接触本构
英文关键词	canals membranes frost protection frost heave damage of canal double membranes anti-seepage cushion coupling of thermo-hydro-mechanics frost heave model contact constitutive relation
语种	中文
国家	中国
收录类别	CSCD
WOS类目	ENGINEERING MULTIDISCIPLINARY
WOS研究方向	Engineering
CSCD记录号	CSCD:6550175
来源机构	西北农林科技大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/239347
作者单位	西北农林科技大学旱区寒区水工程安全研究中心, 旱区农业水土工程教育部重点实验室, 杨凌, 712100
推荐引用方式 GB/T 7714	王羿,王正中,刘铨鸿,等. 基于弹性薄层接触模型研究衬砌渠道双膜防冻胀布设[J]. 西北农林科技大学,2019,35(12):133-141.
APA	王羿,王正中,刘铨鸿,&刘月.(2019).基于弹性薄层接触模型研究衬砌渠道双膜防冻胀布设.农业工程学报,35(12),133-141.
MLA	王羿,et al."基于弹性薄层接触模型研究衬砌渠道双膜防冻胀布设".农业工程学报 35.12(2019):133-141.