| 引用本文: | 蒋佳莉,陆立国,朱 洁,等.宁夏季冻区骨干输水衬砌渠道冻害调查与原因分析[J].灌溉排水学报,2023,42(S1):149-155. |
| JIANG Jiali,LU Liguo,ZHU Jie,et al.宁夏季冻区骨干输水衬砌渠道冻害调查与原因分析[J].灌溉排水学报,2023,42(S1):149-155. |
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| 摘要: |
| 【目的】总结宁夏骨干输水衬砌渠道冻害现状，分析造成渠道冻害问题频发的主要原因。【方法】在对宁夏引黄灌区骨干渠道深入调研的基础上，总结冻害现状及特征规律，量化分析了不同影响因素对冻害影响程度。【结果】梯形断面主要发生错台、整体脱空、滑塌及开裂，弧底梯形断面主要发生坡脚、渠底开裂以及错台，弧形坡脚梯形断面主要发生坡脚开裂以及拱起破坏；渠道不同位置处的最大冻融深度随着地下水位埋深的增大而增大，地下水位埋深对最大冻融深影响的敏感程度顺序为：渠顶>1/2渠坡>渠底；各月平均地面冻深呈现阴坡＞渠底＞阳坡，冻结速率阴坡最大，阳坡与渠底冻结速率大小不一；东西走向阴坡冻深为阳坡的1.3~2.4倍不等，渠底位置冻深最大，阴坡坡脚次之；南北走向阴坡坡脚冻深为阳坡的1.1~2.0倍不等，渠底位置处冻深最小；不同结构型式对冻胀量不均匀程度影响：梯形＞弧形坡脚梯形＞弧底梯形渠道。【结论】破解宁夏引黄灌区骨干渠道冻害破坏严重的问题，仍需从解决高地下水位影响、混凝土材料性能提升、纵缝设置不规范突出问题出发，开展符合区域实际特点的滤透式衬砌结构优化研究，混凝土干湿、冻融、盐渍化交互影响机理研究、混凝土强度及抗老化性能提升相关研究，建立贴合实际的力学分析模型，规范混凝土衬砌板合理设缝位置，并进一步明晰填充材料选用对衬砌变形规律的影响。 |
| 关键词: 宁夏季冻区；骨干渠道；渠道冻害；影响因素 |
| DOI：10.13522/j.cnki.ggps. 2023382 |
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| 基金项目: |
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| Investigation and Cause Analysis of Freezing Damage in the Main Water Conveyance Lining Channel in Ningxia Seasonal Freezing Area |
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JIANG Jiali, LU Liguo, ZHU Jie, NIU Jiayong
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Water Conservancy Research Institute of Ningxia Hui Autonomous Region, Yinchuan 750021, China
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| Abstract: |
| 【Objective】 The purpose of this paper is to summarize the current situation of frost damage in Ningxia's backbone water transmission lining channels and analyze the main reasons for the frequent occurrence of channel frost damage problems, 【Method】 On the basis of in-depth research on the backbone channels of Ningxia Yellow Diversion Irrigation Area, the current situation and characteristics of frost damage were summarized, and the impact of different influencing factors on the degree of frost damage was quantitatively analyzed. 【Result】 The trapezoidal section mainly experienced misalignment, overall detachment, collapse and cracking. The trapezoidal section at the bottom of the arc mainly experienced cracking at the slope toe and at the bottom of the channel, as well as misalignment. The trapezoidal section at the curved slope toe mainly experienced cracking at the slope toe and arching failure. The maximum freeze-thaw depth at different positions of the channel increased with the increase of groundwater level burial depth. The sensitivity order of the influence of groundwater level burial depth on the maximum freeze-thaw depth was: channel top>1/2 channel slope>channel bottom. The average ground freezing depth in each month showed that shady slopes > canal bottoms > sunny slopes. The freezing rate was the greatest on the shady slopes, and varies on the sunny slopes and the bottom of the channels. The freezing depth of the East-West trending shady slope varied from 1.3 to 2.4 times of the sunny slope, with the highest freezing depth at the bottom of the channel and the second highest at the shady slope toe. The freezing depth at the North-South slope toe varied from 1.1 to 2.0 times that of the sunny slope, with the lowest freezing depth at the bottom of the channel. The influence of different structural types on the uneven degree of frost heave: trapezoidal > curved slope toe trapezoidal > curved bottom trapezoidal channel. 【Conclusion】 To solve the serious frost heave failure of the backbone channels in Ningxia Yellow Diversion Irrigation Area, it is still necessary to start from cracking the outstanding problems such as severe frost heave at the bottom of the channel, the impact of high groundwater levels, and the improvement of concrete material performance. We need to carry out research on structural optimization of permeable lining in line with the actual characteristics of the region, research on the interaction mechanism of concrete drying and wetting, freezing and thawing, and salinization, and research on the improvement of concrete strength and anti-aging performance. We need to establish a practical mechanical analysis model, standardize the reasonable joint positions of concrete lining plates, and further clarify the impact of filling material selection on the deformation law of the lining. |
| Key words: Ningxia seasonally frozen areas; backbone channels; channel freezing damage; influencing factor |
