基于统计模型因子优选和异常时段温度因子的拱坝变形异常数据分析  

Analysis on Abnormal Data of Arch Dam Deformation based on Statistical Model Factor Optimizationand Temperature Factor in Abnormal Periods

作　　者：魏文秀 徐笑颜 WEI Wenxiu;XU Xiaoyan(Dam Management Center of SPIC,Xi'an 710000,China;State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi'an University of Technology,Xi'an 710048,China)

机构地区：[1]国家电投集团大坝管理中心,西安710000 [2]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048

出　　处：《西北水电》2024年第5期87-93,共7页Northwest Hydropower

基　　金：国家自然科学基金项目(52279140).

摘　　要：拱坝变形是各种环境因素、材料因素等共同作用的结果,正常工作状况下,拱坝整体工作状态处于线弹性工作状态,局部部位呈现非线性。在拱坝运行中往往存在某些明确的事故或异常,导致坝体发生异常变形甚至改变其变形规律。为精确分析异常事件对大坝变形规律的影响,平衡模型精度和模型可解释性的研究需求,进一步优化拱坝变形统计模型,以某保温板失效的拱坝为例,选取典型垂线测点,以拟合的良好性、模型的简单性和检验的有效性为原则,考虑水压滞后效应、实测温度的影响等因素,使用偏最小二乘回归进行统计模型因子优选,并在模型优选的基础上,加入异常时段温度因子,开展保温板异常时段的定量分析,以确定保温板失效对大坝变形的影响。结果表明:相比于使用周期函数,将实测气温及前期平均气温作为输入变量,可提高统计模型拟合、预测精度;加入异常时段温度因子后统计模型的拟合精度明显提高;夏季温升期间保温板失效会减小坝体变形幅度;在冬季温降作用下,坝顶拱冠处PL4-1测点向下游发生3.5 mm的异常变形,右岸1/4拱处PL2-1测点向下游发生1.5 mm的异常变形。Deformation of the arch dam is the combined action of various environmental and material factors.Under normal condition,the overall working state of the arch dam is in the linear elastic state and local areas are in nonlinear state.Accidents or abnormalities often occur during the operation of arch dams,which lead to abnormal deformation of the dam body or even change its deformation law.In order to accurately analyze the influence of abnormal events on the deformation law of dams,balance the research demand of model accuracy and model interpretability,and further optimize the statistical model of arch dam deformation,taking an arch dam with a failed insulation plate as an example,a typical perpendicular measurement point is selected,the principle of good fitting,simplicity of model and validity of test is taken,the influence of water pressure hysteresis,measured temperature and other factors are considered,and partial least squares regression is used to optimize the statistical model factors,and on the basis of model optimization,the temperature factor of the abnormal period is taken into account.Quantitative analysis of the abnormal period of the insulation plate is carried out to determine the impact of the failure of the insulation plate on the deformation of the dam.The results show that compared with the periodic function,the measured temperature and the average temperature of the previous period can be used as input variables to improve the fitting and prediction accuracy of the statistical model.After adding the temperature factor of the abnormal period,the fitting accuracy of the statistical model is significantly improved.During the summer temperature rise,the failure of the insulation plate will reduce the deformation amplitude of the dam.Under the action of winter temperature drop,the PL4-1 measuring point at the arch crown of the dam crest is abnormally deformed by 3.5 mm downstream,and the PL2-1 measuring point at the arch on the right bank is abnormally deformed by 1.5 mm downstream.

关 键 词：拱坝 安全监测 统计模型 因子优选 异常分析 

分 类 号：TV698.11[水利工程—水利水电工程]