基于改进POT模型的混凝土浇筑仓温度双控指标拟定
Establishment of dual control indices for concrete pouring temperature based on improved POT model
周俊杰 1樊仕文 1崔卫天 2赵越 1黄耀英2
作者信息
- 1. 山西大同抽水蓄能有限公司,山西 大同 037400
- 2. 三峡大学 水利与环境学院,湖北 宜昌 443002
- 折叠
摘要
基于小概率法或最大熵法拟定浇筑仓温度双控指标时对样本数据的极端值保留程度欠缺,而现有文献关于温度双控指标拟定所选取的典型龄期没有明确的物理意义.为避免混凝土浇筑仓温度超过容许最高温度,结合某混凝土坝在高温季节浇筑仓实测温度,采用POT模型拟定了混凝土浇筑仓在绝热温升半熟龄期下的温度双控指标.为了提高结果可靠性,选用基于3σ准则改进的阈值确定方法,并提出了一种改进的POT模型条件概率确定方法.工程实例分析表明:采用改进POT模型与典型小概率法拟定的温度双控指标较为接近,但由于POT模型重点考虑了极端条件下的浇筑仓温度,对极端事件概率下的估计更为准确,由此求出的温度双控指标更合理.此外,选取混凝土浇筑仓在绝热温升半熟龄期作为拟定温度双控指标的典型龄期更利于工程推广.
Abstract
The determination of dual control indices for concrete pouring temperature based on methods such as extreme probability or maximum entropy lacks a sufficient degree of retention for extreme values in sample data.Moreover,existing literature lacks a clear physical significance for the selection of typical age periods for temperature dual control indices.To prevent the concrete pouring temperature from exceeding the maximum allowable temperature,combined with actual measured temperatures during concrete pouring in a certain concrete dam during hot seasons,this study utilized the Peaks Over Threshold(POT)model to establish dual control indices for concrete pouring temperatures during the semi-mature age period under adiabatic temperature rise conditions.To improve the reliability of the results,a threshold determination method based on the improved 3σ criterion was adopted,and an improved conditional probability determination method for the POT model was proposed.Engineering case studies show that the dual control indices for temperature determined by the improved POT model are close to those determined by the typical extreme probability method.However,since the POT model focuses on the temperature of the pouring chamber under extreme conditions,it provides a more accurate estimate of the probability of extreme events,resulting in more reasonable temperature dual control indices.Additionally,selecting the semi-mature age period of the concrete pouring chamber as the typical age period for determining temperature dual control indices is more conducive to engineering application.
关键词
温度双控指标/POT模型/浇筑仓/半熟龄期/小概率法Key words
dual control indices for temperature/POT model/pouring chamber/semi-mature age period/extreme probability method引用本文复制引用
基金项目
国网新源集团有限公司科技项目(SGXY-2022-118)
国家自然科学基金资助项目(52239009)
出版年
2024
NETL
NSTL
万方数据