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基于耐久性可靠度设计理论,以输变电工程基础混凝土长期强度劣化特性为研究对象,通过对浙江、安徽、宁夏和青海等不同地区和不同服役时间的基础混凝土进行取芯和抗压强度试验,分析了区域和时间因素对输变电工程基础混凝土抗压强度的影响,结合概率统计理论研究了基础混凝土长期强度的概率分布规律,并基于贝叶斯统计理论采用共轭分布法对基础长期强度的分布特征参数取值进行研究。结果表明:由于侵蚀环境的不同,不同区域基础混凝土长期强度的均值有所差异;随服役时间的增长,其长期强度呈衰减趋势,且基础服役时间越长其标准差越大,强度试验值越离散;不同地区、不同服役时间、同一强度等级的基础混凝土试验样本归集后,其长期强度的概率特性服从正态分布;C15和C20级输变电基础混凝土的变异系数分别为0.25和0.26,多重因素作用下设计强度等级的提高对其长期强度增强的影响有限。
Based on the design theory of durability reliability and taking the long-term strength degradation of concrete as the research object, the coring and compressive strength tests of basic concrete in different regions and service times in Zhejiang, Anhui, Ningxia and Qinghai are carried out. , Analyzed the influence of regional and time factors on the compressive strength of the basic concrete of transmission and distribution engineering, and studied the probability distribution law of the long-term strength of the basic concrete combined with the theory of probability statistics. Based on the Bayesian statistical theory, Intensity distribution of the characteristic parameters of the value of research. The results show that the mean value of long-term strength of basic concrete in different regions is different due to the difference of erosion environment. The long-term strength declines with the increase of service time, and the longer the standard service life is, the larger the standard deviation is. Dispersion; the probability properties of long-term strength of different types of concrete samples with different strength, strength, and service time in different regions, under normal conditions, were normal distribution; the coefficient of variation of C15 and C20-type basic structural concrete were 0.25 and 0.26 respectively, The effect of multiple factors on the design strength grade has a limited impact on its long-term strength enhancement.