在我国西北高寒地区,混凝土坝常利用表面保温板以避免温度应力导致坝体裂缝的产生,而保温板脱落、缺失等问题不利于结构运行安全。以某高寒拱坝为例,结合热-结构耦合数值模拟方法及位移监测资料的统计模型,分析了保温板脱落对混凝土的影响。数值模拟结果表明:保温板脱落区域的混凝土较未脱落时的温度影响主要位于混凝土表面,其最大温差在9 ℃左右,相应特征点位移差最大为2 mm;而脱落区域混凝土表面最大主拉应力达0.841 MPa。由坝体位移统计模型进一步分析可知,对保温板脱落前后时段测点的位移变化幅值之差最大为6 mm,与数值模拟结果的规律相一致。研究成果可为高寒地区混凝土拱坝保温板问题的研究提供有效参考。
Abstract
Surface thermal insulation boards are commonly employed in concrete dam projects in the alpine region of northwest China to prevent thermal stress-induced cracks in the dam structure. However, issues such as the detachment and loss of insulation boards can jeopardize the structural safety of dam during operations. In this study, an arch dam in the alpine region is used as a case study to analyze the impact of insulation board detachment on concrete. The analysis combines a thermal-structural coupling numerical simulation method with a statistical model based on displacement monitoring data. The numerical simulation results demonstrate that the temperature influence in the detachment area mainly occurs on the concrete surface. The maximum temperature difference is approximately 9 ℃, and the corresponding displacement difference of characteristic points reaches up to 2 mm. The maximum principal tensile stress on the concrete surface in the detachment area is 0.841 MPa. Moreover, the statistical model of dam body displacement confirms that the amplitude of displacement changes before and after detachment can reach 6 mm, aligning with the patterns observed in the numerical simulation results. The research findings provide valuable insights for investigating thermal insulation boards on concrete arch dams in alpine areas.
关键词
拱坝 /
表面保温板 /
温度位移 /
温度应力 /
仿真模拟 /
安全监测 /
高寒地区
Key words
arch dam /
thermal insulation board /
thermal displacement /
thermal stress /
numerical simulation /
safety monitoring /
high and cold area
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参考文献
[1] CHEN B, GU C, BAO T,et al. Failure Analysis Method of Concrete Arch Dam Based on Elastic Strain Energy Criterion[J]. Engineering Failure Analysis,2016,60:363-373.
[2] 朱伯芳. 混凝土坝温度控制与防止裂缝的现状与展望[J]. 水利学报, 2006, 37(12): 1424-1432.
[3] 张 锐, 李庆中, 周 伟. 几个参数对拱坝温度及应力影响的研究[J]. 长江科学院院报, 2009, 26(3): 44-48.
[4] CAO W, YANG B, TIAN Z, et al. Research on Thermal Insulation and Moisture Holding of Concrete Dams[J]. Journal of Basic Science and Engineering, 2009, 17(2): 179-187.
[5] WANG Y, CHEN L, WANG Z. Research Progress of Dam Surface Coating Material for Concrete in Hydraulic Engineering[J]. Materials Reports, 2016, 30: 81-86.
[6] 沈思朝, 颉志强, 王首豪. 基于数值仿真的水闸温控措施敏感性分析[J]. 长江科学院院报, 2022, 39(1): 146-154.
[7] 崔金良, 邹良智, 高 莉, 等. 拉西瓦拱坝中XPS板的保温保湿效果分析[J]. 青海大学学报(自然科学版), 2011, 29(6): 13-15.
[8] 张晓飞, 陈尧隆, 李守义, 等.寒冷地区混凝土坝表面保温效果研究[J].河北农业大学学报,2010, 33(1): 98-103.
[9] CHEN B, HE M, HUANG Z,et al. Long-tern Field Test and Numerical Simulation of Foamed Polyurethane Insulation on Concrete Dam in Severely Cold Region[J]. Construction and Building Materials, 2019, 212: 618-634.
[10] 杨 平, 石长征, 伍鹤皋, 等. 寒冷地区坝内垫层管运行期温度效应及保温措施研究[J]. 四川大学学报(工程科学版), 2016, 48(增刊1): 47-54.
[11] 沈宇鹏,王笃礼,林园榕,等.越冬基坑水平冻胀的防治措施效果分析[J]. 岩土力学,2021,42(5):1434-1442.
[12] ZHANG Y, PAN J, SUN X,et al. Simulation of Thermal Stress and Control Measures for Rock-filled Concrete Dam in High-altitude and Cold Regions[J]. Engineering Structures,2021,230,doi: 10.1016/j.engstruct.2020.111721.
[13] YANG J, QU X, HU D,et al. Research on Singular Value Detection Method of Concrete Dam Deformation Monitoring[J]. Measurement,2021,179,doi: 10.1016/j.measurement.2021.109457.
[14] TATIN M, BRIFFAUT M, DUFOUR F,et al. Statistical Modelling of Thermal Displacements for Concrete Dams: Influence of Water Temperature Profile and Dam Thickness Profile[J]. Engineering Structures,2018,165:63-75.
[15] GU H, YANG M, GU C S. A Factor Mining Model with Optimized Random Forest for Concrete Dam Deformation Monitoring[J]. Water Science and Engineering, 2021, 14(4): 330-336.
[16] WEI B, LIU B, YUAN D,et al. Spatiotemporal Hybrid Model for Concrete Arch Dam Deformation Monitoring Considering Chaotic Effect of Residual Series[J]. Engineering Structures, 2021, 228,doi: 10.1016/j.engstruct.2020.111488.
[17] BIAN K, WU Z. Data-based Model with EMD and a New Model Selection Criterion for Dam Health Monitoring[J]. Engineering Structures, 2022, 260,doi: 10.1016/j.engstruct.2022.114171.
[18] 李秀琳, 夏世法, 李 蓉, 等. 某碾压混凝土重力坝上游保温板脱落后的混凝土温度应力反馈分析[J]. 大坝与安全, 2015(6): 48-50.
[19] 林 锋, 赵 妮, 孙粤琳, 等. 新疆某混凝土重力坝运行期温度场和应力场反馈分析[J]. 中国水利水电科学研究院学报, 2020, 18(5):354-360.
[20] 朱伯芳. 大体积混凝土温度应力与温度控制[M]. 2版. 北京: 中国水利水电出版社, 2012.
[21] 邹良智, 高 莉, 崔金良. 挤塑聚苯乙烯保温板在拉西瓦工程建设中的应用及存在问题分析[J]. 青海大学学报(自然科学版), 2011, 29(4): 48-51.
[22] 黄耀英.大坝安全监控正反分析方法与优化调控[M].北京:中国水利水电出版社,2016.
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