贡力, 贾治元, 李义强, 杜强业, 张娇艳. 流冰对输水明渠混凝土衬砌的撞击影响[J]. 农业工程学报, 2021, 37(21): 163-172. DOI: 10.11975/j.issn.1002-6819.2021.21.019
    引用本文: 贡力, 贾治元, 李义强, 杜强业, 张娇艳. 流冰对输水明渠混凝土衬砌的撞击影响[J]. 农业工程学报, 2021, 37(21): 163-172. DOI: 10.11975/j.issn.1002-6819.2021.21.019
    Gong Li, Jia Zhiyuan, Li Yiqiang, Du Qiangye, Zhang Jiaoyan. Impact of drift ice on concrete lining of open water conveyance channel[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2021, 37(21): 163-172. DOI: 10.11975/j.issn.1002-6819.2021.21.019
    Citation: Gong Li, Jia Zhiyuan, Li Yiqiang, Du Qiangye, Zhang Jiaoyan. Impact of drift ice on concrete lining of open water conveyance channel[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2021, 37(21): 163-172. DOI: 10.11975/j.issn.1002-6819.2021.21.019

    流冰对输水明渠混凝土衬砌的撞击影响

    Impact of drift ice on concrete lining of open water conveyance channel

    • 摘要: 为研究西北寒冷地区长距离输水工程中流冰对输水明渠的撞击影响,该研究运用LS-DYNA软件模拟不同工况下流冰与输水明渠碰撞挤压过程,并通过室内模型试验进行相应验证,探求水-空气耦合介质中流冰碰撞输水明渠的破坏规律。结果表明:流冰速度对明渠衬砌撞击的最大等效应力与X方向最大位移呈现出近似的Pseudo-Voigt函数峰值曲线关系。流冰压缩强度对明渠衬砌撞击的最大等效应力与X方向最大位移呈现出近似的线性关系。综合分析所模拟的不同组合工况可以看出,对明渠衬砌撞击影响明显的组合区间是流冰压缩强度为1.825~3.199 MPa、流冰速度为3.5~4.5 m/s时的组合情况,其等效应力值为4.3~16.8 MPa、X方向最大位移值为2.59×10-5~5.52×10-5 m;对明渠衬砌撞击影响最大的双因素组合是流冰压缩强度为3.059 MPa、流冰速度为4.0 m/s的组合情况,其等效应力值为16.8 MPa、X方向最大位移值为5.52×10-5 m;对明渠衬砌撞击影响较为不明显的组合区间是流冰速度为0.5~1.0 m/s、压缩强度为1.825~ 2.375 MPa时的组合情况,其等效应力为0.7~2.8 MPa、X方向最大位移为0.24×10-5~0.52×10-5 m。同时,模拟值与试验结果基本吻合,表明所采用的数值模拟仿真模型准确可靠,其结果可为寒冷地区冬季输水工程安全运营提供帮助。

       

      Abstract: Abstract: Large blocks of drift ice have posed a strong impact on the open channels in the long-distance water delivery projects in the alpine regions. The drift ice is easy to form with the different speeds and compression strength in the high latitudes of northwestern China, especially the north of 35°N latitude. Particularly, the ice period lasts for 4 to 5 months in the cold and dry winter, covering from the freezing in November to the open in the following spring. The long-term collision of drift ice can cause some serious damage to the concrete lining of an open channel, such as cracking or peeling of the surface. The lining structure can result in different degrees of damage and deformation, even a threat to the long-term stability of water supply, including the safe operation of the open channel, irrigation of farmland, and water use for humans and animals. Therefore, this study aims to clarify the impact of the drift ice on the open delivery channels in the long-distance water delivery projects in the alpine regions. A collision model of the drift ice and open channels was also established as a water-air coupling medium using the ANSYS/LS-DYNA platform. Specifically, the collision motion equation of drift ice in the open channel was obtained, according to the display of time integration. The contact-collision process was assumed as a symmetric penalty function. The fluid-structure coupling calculation was then implemented considering the coupling effect between water-air-flow ice-open channels. After that, LS-DYNA SOLVER software was used to simulate the collision and extrusion of drift ice and open channel under different working conditions. As such, the degree of the collision was classified to evaluate the damage caused by the drift ice to the lining of the open channel. An indoor model test was carried out to verify the model. A damage law of drift ice was thus found in the water-air coupling medium when colliding with the open channel. The results showed that there was an approximate Pseudo-Voigt function peak curve relationship for the maximum equivalent stress and the maximum displacement in the X direction of the impact of the ice velocity on the open channel lining. Besides, there was an approximately linear relationship for the maximum equivalent stress and the maximum displacement in the X direction of the impact of drift ice compression strength on the lining of open channels. Furthermore, a combination interval posed a significant impact on the open channel lining, where the compressive strength of the flowing ice was 1.825-3.199 MPa, and the speed of the flowing ice was 3.5-4.5 m/s. This equivalent stress value of impact was 4.3-16.8 MPa, and the maximum displacement value in the X direction was 2.59×10-5-5.52×10-5 m. More importantly, a two-factor combination was posed the greatest impact on the open channel lining impact, where the flow ice compression strength of 3.059 MPa, and the flow ice velocity of 4.0 m/s. This equivalent stress value of impact was 16.8 MPa, and the maximum displacement value in the X direction was 5.52×10-5 m. By contrast, the combination interval presented a fewer outstanding impact on the open channel lining, where the drift ice velocity of 0.5-1.0 m/s, and the compressive strength was 1.825-2.375 MPa. This equivalent stress of impact was 0.7-2.8 MPa, and the maximum displacement in the X direction was 0.24×10-5-0.52×10-5 m. Therefore, there was a significant correlation between the temperature and the compressive strength of drift ice, while the flow velocity and the speed of drift ice. Correspondingly, the influence of the ice load needed to be considered in the design stage of the open channel lining structure. The findings can also provide sound theoretical and technical support to the safe operation of long-distance water transportation projects for the alpine regions in winter.

       

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