钢纤维混凝土面板堆石坝的抗震性能数值分析

Numerical analysis of seismic performance of steel fiber reinforced concrete face rockfill dam

混凝土面板的损伤开裂是威胁面板堆石坝安全的重要因素,纤维混凝土是减小面板开裂的工程措施之一。本文将钢纤维混凝土的本构关系引入到了塑性损伤模型中,并联合广义塑性模型,对200 m级的面板堆石坝进行了弹塑性地震反应分析,分别研究了钢筋混凝土面板和钢纤维混凝土面板的动力损伤及发展过程,并考虑了不同钢纤维含量的影响。结果表明,塑性损伤模型可以较好地模拟钢纤维混凝土的应力-应变关系;钢含量相同时,钢筋混凝土面板和钢纤维混凝土面板的损伤区域均在2/3坝高以上;相比于钢筋混凝土面板,钢纤维混凝土面板地震损伤程度降低了18%,损伤范围减小55%;钢纤维含量从70 kg/m3增加到110 kg/m3后,钢纤维混凝土面板的损伤程度降低14%,损伤范围减小80%。研究结果对钢纤维混凝土应用于强震区面板坝的面板抗裂和提高大坝极限抗震能力提供了依据。

The damage failure of concrete slab is a threat to Concrete Faced Rockfill-Dam（CFRD）. Fiberreinforced concrete is one of the engineering measures to reduce the damage of the face slab. In this pa-per,the steel fiber reinforced concrete（SFRC） is used as a constructional material of face slab to improvethe ultimate seismic-resistance capacity of the dam. The constitutive relationship of SFRC is introduced intothe plastic damage model. By combining the generalized plasticity model and plastic damage model,an elas-to-plastic seismic response analysis was performed for a 200-m-high CFRD. The process and developmentof dynamic damage in reinforced concrete（RC） face slabs and SFRC face slabs were analyzed. The effectsof different steel fiber contents are considered. The results show that the plastic damage model can simulatethe stress-strain relationship of SFRC well. Using the equivalent steel content,the tensile damage positionsand areas of weakness in RC slab and SFRC slab are all distributed above two-thirds of the dam height.Compared with the RC slabs,the maximum tensile damage of SFRC slab is reduced by 18%,and the ar-ea of weakness is reduced by 55%. The maximum tensile damage of the SFRC slab was decreased by 14%and the area of weakness was decreased by 80% as the fiber content increased from 70kg/m3 to 110kg/m3.