Seismic Performance of Middle Columns in Subway Station Structures Strengthened with CFRP Sheets
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摘要: 现浇地铁地下车站结构中柱柱端往往是抗震薄弱区域,采用在中柱顶底端对称包裹CFRP布的加固方法,并基于ABAQUS软件,建立了土-地下结构非线性静动力耦合相互作用的三维有限元分析模型,通过设置不同CFRP布包裹范围及层数的数值模型,研究其对加固效果的影响。研究结果表明,CFRP布可在不改变中柱侧向刚度的情况下增强中柱抗侧向变形能力,同时CFRP布能够减轻中柱顶底端核心混凝土剪切破坏,使震后中柱仍具有一定的承载力,提升了中柱延性。相同地震动输入条件下,CFRP布加固柱核心区混凝土损伤、残余侧向变形及塑性变形较未加固柱有明显改善,抗震性能有明显提高。CFRP布加固效果不会随着包裹范围和层数的增加始终保持线性增长,存在最优值使地下车站结构中柱抗震性能达到最佳,因此建议中柱顶底端CFRP布总包裹范围为中柱高度的1/2,包裹层数为5层。Abstract: In cast-in-place subway station structures, the ends of middle columns are often the most seismically vulnerable areas. This paper proposes a reinforcement method involving symmetrically wrapping CFRP sheets around the ends of middle columns. A three-dimensional finite element model was developed to simulate the nonlinear static and dynamic coupling interactions between the soil and underground structure using ABAQUS software. The influence of wrapping range (b) and the number of wrapping layers (n) on the reinforcement effectiveness was investigated by setting up numerical models with varying wrapping ranges and layer numbers. The objective was to analyze how CFRP wrapping affects the seismic response characteristics of middle columns in subway stations. The results show that CFRP wrapping enhances the lateral deformation resistance of middle columns without altering their lateral stiffness. Additionally, CFRP sheets reduce shear damage in the core concrete at the column ends, maintaining the column's bearing capacity post-earthquake and improving its ductility. Under identical ground motion conditions, CFRP-reinforced columns exhibit significantly reduced concrete damage, residual lateral deformation, and plastic deformation in the core area compared to unreinforced columns, resulting in improved seismic performance. However, the strengthening effect of CFRP does not increase linearly with the wrapping range or the number of layers; there is an optimal combination for achieving the best seismic performance. Based on the findings, the optimal wrapping range is 1/2 of the column height, with five wrapping layers ( b = 1/2, n = 5 ).
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Key words:
- Carbon fiber reinforced composites /
- Subway /
- Stations /
- Reinforce /
- Seismic performance /
- Numerical simulation
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表 1 大开单层车站土层主要物理力学参数
Table 1. Material parameters for soil
土质 深度/m 密度/(kg·m−3 ) 剪切波速/(m·s−1) 泊松比 黏聚力/kPa 内摩擦角/(°) 人工填土 0~1.0 1 900 140 0.333 20 15 全新世砂土 1.0~5.1 1 900 140 0.488 1 40 全新世砂土 5.1~8.3 1 900 170 0.493 1 40 更新世黏土 8.3~11.4 1 900 190 0.494 30 20 更新世黏土 11.4~17.2 1 900 240 0.490 30 20 更新世砂土 17.2~39.2 2 000 330 0.497 1 40 表 2 模拟工况设计
Table 2. Simulation of the working condition
组号 编号 配布情况 b n A组 A1 0 0 B组 B1 1/8 5 B2 1/2 5 B3 1 5 C组 C1 1 3 C2 1 7 表 3 不同CFRP布包裹范围中柱残余侧向变形
Table 3. Residual deformation of columns in different CFRP cloth wrapping ranges
地震动 PBA/g 残余侧向变形/mm 残余侧向变形衰减百分比/% 等效塑性变形/% 等效塑性变形衰减百分比/% n=0
b=0n=5
b=1/8n=5
b=1/2n=5
b=1n=0
b=0n=5
b=1/8n=5
b=1/2n=5
b=1n=0
b=0n=5
b=1/8n=5
b=1/2n=5
b=1n=0
b=0n=5
b=1/8n=5
b=1/2n=5
b=1Kobe波 0.1 2.57 2.33 1.43 1.49 0 9.3 44.3 42.0 0.19 0.17 0.12 0.13 0 10.5 36.8 31.6 0.2 4.13 3.67 1.97 2.03 0 11.1 52.3 50.8 0.32 0.28 0.19 0.19 0 12.5 40.6 40.6 0.3 6.71 5.89 2.83 3.13 0 12.2 57.8 53.4 0.54 0.47 0.31 0.32 0 12.9 42.6 40.7 卧龙波 0.1 1.03 0.92 0.47 0.48 0 10.7 54.4 53.4 0.08 0.07 0.06 0.05 0 12.5 25.0 37.5 0.2 2.70 2.40 1.23 1.25 0 11.0 54.5 53.7 0.21 0.17 0.12 0.13 0 14.3 42.9 38.1 0.3 4.06 3.54 1.83 1.85 0 12.8 54.9 54.4 0.31 0.26 0.17 0.18 0 15.0 45.2 41.9 什邡八角波 0.1 2.49 2.22 1.31 1.39 0 10.8 47.4 44.2 0.18 0.16 0.11 0.12 0 11.1 38.9 33.3 0.2 4.07 3.54 1.84 1.85 0 13.1 54.8 54.8 0.31 0.25 0.16 0.18 0 19.4 48.4 41.9 0.3 6.11 5.01 2.52 2.60 0 18.0 58.8 57.4 0.49 0.39 0.25 0.27 0 20.4 50.0 44.9 表 4 不同CFRP布包裹层数中柱的残余侧向变形
Table 4. Residual deformation of columns in different CFRP cloth wrapping layers
地震动 PBA/g 残余侧向变形/mm 残余侧向变形衰减百分比/% 等效塑性变形/% 等效塑性变形衰减百分比/% n=0
b=0n=3
b=1n=7
b=1n=5
b=1n=0
b=0n=3
b=1n=7
b=1n=5
b=1n=0
b=0n=3
b=1n=7
b=1n=5
b=1n=0
b=0n=3
b=1n=7
b=1n=5
b=1Kobe波 0.1 2.57 2.22 1.48 1.49 0 13.6 42.4 42.0 0.19 0.17 0.12 0.13 0 10.5 36.8 31.6 0.2 4.13 3.56 2.03 2.03 0 13.8 50.8 50.8 0.32 0.27 0.19 0.19 0 15.6 40.6 40.6 0.3 6.71 5.58 3.15 3.13 0 14.2 53.1 53.4 0.54 0.44 0.32 0.32 0 18.5 40.7 40.7 卧龙波 0.1 1.03 0.94 0.48 0.48 0 8.7 53.4 53.4 0.08 0.07 0.05 0.05 0 12.5 37.5 37.5 0.2 2.70 2.39 1.65 1.25 0 11.5 38.9 53.7 0.21 0.18 0.12 0.13 0 14.3 42.9 38.1 0.3 4.06 3.45 1.82 1.85 0 15.0 55.2 54.4 0.31 0.26 0.16 0.18 0 15.0 48.4 41.9 什邡八角波 0.1 2.49 2.14 1.37 1.39 0 14.1 45.0 44.2 0.18 0.17 0.11 0.12 0 5.6 38.9 33.3 0.2 4.07 3.45 1.85 1.85 0 15.2 54.5 54.8 0.31 0.27 0.18 0.18 0 14.8 41.9 41.9 0.3 6.11 5.17 2.59 2.60 0 15.4 57.6 57.4 0.49 0.38 0.27 0.27 0 22.4 44.9 44.9 -
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