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基于PPA-POT的RCCD变形监测控制值拟定方法

2021-03-28赵二峰李波朱延涛

人民黄河 2021年3期

赵二峰 李波 朱延涛

摘 要:在碾压混凝土坝(RCCD)长期服役过程中,变形是能够直观反映大坝工作性态的主要性能参数之一。为了有效监控大坝运行状态,有必要对坝体变形拟定监测控制值。为突破传统单一测点指标拟定的局限性,针对碾压混凝土坝变形空间结构关联分布特性,构建了多测点融合的坝体变形场模型,利用投影寻踪方法(PPA)确定各测点权重,在此基础上,利用POT模型进行监测控制值的拟定。工程应用结果表明了本文方法的可行性与适用性。

关键词:碾压混凝土坝;变形场;监测控制值;投影寻踪方法;POT模型

Abstract:In the long service of Roller Compacted Concrete Dam (RCCD), deformation is one of the main performance parameters which can directly reflect the working behavior of the dam. In order to effectively monitor the safety of dam operation, it is necessary to determine the monitoring control values for deformation. In order to overcome the limitations which the traditional dam deformation monitoring control values only consider the single point. This paper constructed a deformation field model of RCC dam with multi-measurement point fusion and used Projection Pursuit Analysis (PPA) to determine the weight of each measurement point according to the spatial structure correlation distribution characteristics of RCC dam deformation. On this basis, the POT model was proposed to determine the monitoring control values. The results of engineering application show the feasibility and applicability of the method in this paper.

Key words: roller compacted concrete dam; deformation field; monitoring control value; projection pursuit analysis; POT model

碾压混凝土坝(RCCD)筑坝技术特殊[1],大坝变形作为能直观反映其运行性态的监测量,是监测和判断大坝运行性态的主要手段之一[2-3]。大坝变形表现为动态非线性[4],深入挖掘大坝变形的演变规律具有重要意义[5]。变形指标是表征大坝工作状态是否正常和评价大坝安全与否的关键指标,可以通过监测效应量控制值来评估大坝的安全性。常用的估计监测效应量控制值的方法有数理统计法和结构分析法[6],针对长期监测资料序列,通常采用数理统计法拟定大坝变形监测效应量控制值。顾冲时等[7]提出了龙羊峡混凝土坝三级监控指标拟定的原理和方法;丛培江等[8]建立了基于最大熵原理的大坝安全监控指标拟定模型;雷鹏等[9]通过构建空间变形熵,利用投影寻踪法(PPA)确定权重,采用传统数理统计法和结构分析法计算了混凝土坝整体变形熵预警指标。……

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