基于Hoek-Brown破坏准则的FRP约束损伤混凝土圆柱与方柱统一强度模型

Unified strength model based on the Hoek-Brown failure criterion for fibre-reinforced polymer-confined pre-damaged concrete columns with circular and square cross sections

纤维增强聚合物(FRP)具有强度高、重量轻、耐腐蚀、施工方便等优点,广泛应用于受损混凝土柱的修复和加固。现有的强度模型大多是通过实验数据的回归分析建立的。本文利用Hoek-Brown破坏准则,提出了一种新的强度统一模型。为了研究FRP约束混凝土损伤和未损伤柱的强度,作者从已发表的文献中收集了900个试验数据,建立了包含各试件截面形状、损伤类型、损伤程度和FRP约束刚度的大型数据库。利用Hoek-Brown破坏准则建立了一种新的强度模型,该模型适用于未损伤、荷载损伤和火灾损伤的圆柱和方柱。在数据库的基础上,对发表文献中已有的强度模型和本文提出的强度模型进行了评估。评估结果表明,该模型能较好地预测FRP约束损伤和未损伤混凝土柱的抗压强度。

Fibre-reinforced polymer(FRP)has the advantages of high strength,light weight,corrosion resistance and convenient construction and is widely used in repairing and strengthening damaged concrete columns.Most of the existing strength models were built by regression analysis of experimental data;however,in this article,a new unified strength model is proposed using the Hoek-Brown failure criterion.To study the strength of FRP-confined damaged and undamaged concrete columns,900 test data were collected from the published literature and a large database that contains the cross-sectional shape of each specimen,the damage type,the damage level and the FRP-confined stiffness was established.A new strength model using the Hoek-Brown failure criterion was established and is suitable for both circular and square columns that are undamaged,load-damaged and fire-damaged.Based on the database,most of the existing strength models from the published literature and the model proposed in this paper were evaluated.The evaluation shows that the proposed model can predict the compressive strength for FRP-confined pre-damaged and undamaged concrete columns with good accuracy.