作者：张明月¹, 姚烨², 张子俊¹

作者单位：1. 沈阳城市建设学院土木工程系，辽宁 沈阳 110167;
2. 东北大学资源与土木工程学院，辽宁 沈阳 110004

关键词：时变评估模型;冻融损伤;RC框架梁柱;等效冻融循环次数计算模型

摘要：

为评估严寒地区在役RC框架结构的时变化承载能力与变形能力。该文首先利用最冷月平均气温θ为指标建立实际环境下的年均冻融循环次数F_act计算式；进而考虑室内外损伤比例系数S、饱含水时间比例系数k，将F_act等效换算为基于“快冻法”的实验室冻融循环次数F_Q。同时，以抗压强度为冻损指标，建立可将F_Q换算为基于“人工气候”的实验室冻融循环次数F的等效冻融循环次数计算模型。利用已有研究成果建立弯曲破坏未冻融RC梁柱特征状态承载力与变形能力计算式，进而提出可考虑F、f_c、n影响的冻融损伤RC框架梁柱特征状态承载力与变形能力计算式。在此基础上，建立冻融损伤RC框架梁柱承载能力与变形能力时变评估模型。研究可为严寒地区在役RC框架结构的冻融劣化时变评估提供参考。

Time-dependent evaluation model of load carrying and deformation capacity of frost-damaged RC frame beam-column
ZHANG Mingyue¹, YAO Ye², ZHANG Zijun¹
1. Department of Civil Engineering, Shenyang Urban Construction University, Shenyang 110167, China;
2. School of Resources and Civil Engineering, Northeastern University, Shenyang 110004, China
Abstract: In order to evaluate the time-varying bearing capacity and deformation capacity of in-service RC frame structure in severe cold area. In this paper, the annual average number of freeze-thaw cycles in the actual environment F_act is calculated by using the average temperature of the coldest month θ as the index. Furthermore, considering the indoor and outdoor damage ratio coefficient S and the water saturated time ratio coefficient k, the F_act is equivalent to the number of laboratory freeze-thaw cycles F_Q based on the “quick freezing method”. Simultaneously, taking the compressive strength as the freezing loss index, the calculation model of equivalent freezing and thawing cycles which can convert F_Q into laboratory freezing and thawing cycles F based on “artificial climate” is established. Based on the existing research results, the formulas for calculating the characteristic state load carrying capacity and deformation capacity of unfrozen RC beam-column under flexure failure are established, and then the formulas for calculating the characteristic state bearing capacity and deformation capacity of frost-damaged RC frame beam-column considering the effects of F, f_c and n are proposed. On this basis, the time-dependent evaluation model of bearing capacity and deformation capacity of frozen-thawed damage RC frame beam-column is established, and the time-varying evaluation of freeze-thaw deterioration of RC frame structural members in severe cold area is realized. The research can provide a reference for the time-varying assessment of freeze-thaw deterioration of in-service RC frame structures in severe cold areas.
Keywords: time-dependent evaluation model;frost-damage;RC frame beam-column;calculation model of equivalent freeze thaw cycles
2022, 48(7):147-156,162  收稿日期: 2021-05-18;收到修改稿日期: 2021-07-08
基金项目: 国家自然科学基金资助项目（51978422）
作者简介: 张明月（1981-），女，辽宁沈阳市人，副教授，硕士，主要从事建筑结构抗震工作
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