| 刘铨鸿,郭明,王正中,陆立国,葛建锐,李瀚翔.寒区河湖与灌排渠道模袋混凝土护岸冻胀破坏机理[J].水利学报,2022,53(2):230-242 |
| 寒区河湖与灌排渠道模袋混凝土护岸冻胀破坏机理 |
| Frost failure mechanism of fabriform concrete protection for rivers， lochs and irrigation and drainage canals in cold regions |
| 投稿时间：2021-08-04 |
| DOI：10.13243/j.cnki.slxb.20210696 |
| 中文关键词: 模袋混凝土护岸 卵砾石护底 浅埋地下水 冻土水热力耦合 冻胀破坏 |
| 英文关键词: fabriform concrete protection gravel beds protection shallow buried water table thermo-hydro-mechanical coupling of frozen soil frost heave damage |
| 基金项目:国家自然科学基金项目（U2003108，51279168）；国家重点研发计划项目（2017YFC0405103）；冻土工程国家重点实验室开放基金项目（SKLFSE201801）；江西省教育厅科学技术研究项目（GJJ190621） |
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| 中文摘要: |
| 我国北方寒区河湖与灌排渠道护岸冻胀破坏普遍严重。卵砾石护底模袋混凝土衬砌护岸因施工方便获得广泛应用。但目前针对这种复合衬砌结构的冻胀破坏机理尚不明确，难于规范化设计。本文基于冻土水热力三场耦合理论，考虑衬砌与基土的界面相互作用建立了河渠护岸衬砌冻胀数值分析模型。以宁夏西干渠工程为例，对卵砾石护底的模袋混凝土、卵砾石护底的普通混凝土以及全断面混凝土三种典型衬砌形式的弧脚梯形渠道进行冻胀破坏分析和对比研究。结果表明，卵砾石护底的排水作用可使边坡基土冻前体积含水率和冻后体积含冰率分别减少约27.8%和30%；模袋及卵砾石护底削减了冻结约束和底板约束，使坡板拉应力减少20%~70%，冻胀量削减约30%，不均匀冻胀量减少约50％；模袋混凝土护岸冻胀破坏表现出混凝土开裂、模袋达到比例极限、模袋达到极限强度的三个阶段，在混凝土开裂后模袋仍具备较强的承拉能力使护岸衬砌仍能承受冻胀发展并防止滑塌失稳破坏，当以模袋拉应力达到比例极限为失效准则时，抗冻胀能力提高约47.1%，负温抵抗能力提高约30%。此项研究可为我国北方寒区浅埋地下水河渠护岸采用卵砾石护底模袋混凝土衬砌提供设计手段与合理依据。 |
| 英文摘要: |
| Frost failure of slope protection measures for rivers, lochs and irrigation and drainage canals is generally serious in the cold regions of northern China. Fabriform concrete-lined canals with gravel beds have been widely applied because of their easy construction. However, the frost failure phenomenon of this composite lining structure remains unclear, so it is difficult to achieve design standardisation. In this paper,a numerical model of frost heave for lined canals was established based on the thermo-hydro-mechanical coupling theory of frozen soil and the interaction mechanism between lining and foundation soil. Choosing the Ningxia West Main Canal Project as an example, frost failure analysis and comparative studies of three typical lining forms of curved corner trapezoidal canals, namely, fabriform concrete with gravel beds, ordinary concrete with gravel beds and full section concrete, were carried out. The numerical results indicate that due to the drainage effect of bedded gravel, the volumetric water content before freezing and the volumetric ice content in the slope during the freezing process were reduced by approximately 27.8% and 30%,respectively. Fabriform and bedded gravel application decreased the adfreeze bond and constraint reaction in the bottom slab, respectively. Therefore, the tensile stress of slope slabs was reduced by 20%~70%, frost heave occurrence was reduced by approximately 30% and the coefficient of uneven frost heave was reduced by approximately 50%. There occurred three stages in the process of frost failure of fabriform concrete linings, namely, concrete cracking, the fabriform material reaching its proportional limit and the fabriform material reaching its ultimate tensile strength. After concrete cracking, the tensile capacity of the fabriform material allowed the lining to withstand the development of frost heave and prevent sliding and destabilisation failure. With the use of the fabriform elastic proportional limit as a failure criterion, the frost heave resistance was increased by approximately 47.1%, and the negative temperature resistance was increased by approximately 30%. This study provides design means and reasonable basis for the use of fabriform concrete-lined canals with gravel beds of shallow buried water table slope protection in the cold regions of northern China. |
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