Testing Research on the Relation between the Crack Distinctive Feature and the Structural Performance of Reinforced Concrete T-beams
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摘要: 通过室内钢筋混凝土模型T梁的荷载试验, 将裂缝特征统计参数经回归分析并结合结构非线性分析, 建立了从裂缝统计特征参数推测结构配筋率的方法, 从而对已严重开裂的钢筋混凝土T型梁桥进行有效评估。将结构外观检查的定性评估提高为定量评估, 具有重要使用价值。Abstract: Many cracks in the existing reinforced concrete T beam bridges with low criterion are found.Based on crack distinctive feature obtained from the reinforced concrete T beam test in the laboratory, the structural steel ratio in reinforced concrete T beams with many cracks can be forecasted by the way of regressive and nonlinear analysis so that their structural performance can be effectively assessed.The method is simple in theory, convenient in application and reliable in precision. This method changes the assessment for structure from qualitative anlysis to the quantitative calculation.
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表 1 裂缝特征参数
M/kN·m lcr/mm 4.576 52.0 0.52 90 5.275 71.0 0.77 90 5.882 72.0 0.91 80 6.516 90.6 1.05 80 7.171 94.7 1.14 80 7.810 101.4 1.20 80 8.460 107.4 1.40 70 9.100 109.8 1.62 70 表 2 截面非线性分析与参数α、β计算
梁号 M/kN·m x/mm φ (×10-3) β α T1-1 4.576 54.4 3.95 0.260 0.400 2.80 1.44 5.275 54.4 4.56 0.355 0.592 2.05 1.12 5.882 53.9 5.18 0.360 0.705 2.03 1.07 6.516 53.9 5.73 0.453 0.814 1.61 1.03 7.171 53.7 6.24 0.474 0.884 1.54 1.03 7.810 53.7 6.80 0.507 0.930 1.44 1.07 8.460 53.6 7.37 0.537 1.094 1.36 0.98 9.100 53.6 7.95 0.549 1.266 1.33 0.92 T1-2 4.865 54.5 4.21 0.349 0.600 2.08 1.02 5.522 54.4 4.79 0.372 0.667 1.96 1.03 6.208 54.3 5.46 0.433 0.679 1.68 1.17 6.849 54.1 5.96 0.479 0.860 1.52 1.08 7.511 54.0 6.54 0.504 0.866 1.45 1.10 8.168 53.7 7.12 0.516 0.925 1.42 1.18 8.778 53.2 7.65 0.558 1.098 1.32 1.03 9.746 53.1 8.52 0.558 1.406 1.25 0.89 T2-1 3.975 40.5 5.91 0.441 0.415 1.81 2.14 4.534 40.5 6.76 0.500 0.577 1.61 1.87 5.190 40.3 7.74 0.533 0.802 1.50 1.46 5.782 40.1 7.81 0.549 0.976 1.46 1.43 6.503 39.7 9.72 0.586 1.200 1.39 1.30 T2-2 4.550 40.3 6.76 0.420 0.430 1.90 2.51 5.200 40.1 7.73 0.446 0.624 1.79 1.98 5.847 40.0 8.70 0.543 0.842 1.47 1.65 6.515 39.6 9.71 0.620 1.144 1.29 1.36 7.150 39.2 10.60 0.693 1.258 1.16 1.36 表 3 预测μ和Mj与实际μs和Ms
梁号 加载M/kN·m μs μ Ms/kN·m Mj/kN·m T1-1 4.567 0.0209 0.0232 11.0 10.360 11.107 7.2 5.275 0.0209 0.0229 9.6 10.360 10.970 5.9 5.882 0.0209 0.0226 8.1 10.360 10.849 4.7 6.516 0.0209 0.0217 3.8 10.360 10.401 0.4 7.171 0.0209 0.0213 1.9 10.360 10.226 -1.3 7.810 0.0209 0.0210 0.5 10.360 10.078 -2.7 8.460 0.0209 0.0208 -0.5 10.360 9.959 -3.9 9.100 0.0209 0.0210 0.5 10.360 10.096 -2.8 T1-2 4.865 0.0209 0.2230 6.7 10.360 10.719 3.5 5.522 0.0209 0.0219 4.8 10.360 10.491 1.3 6.208 0.0209 0.0212 1.4 10.360 10.167 -1.9 6.849 0.0209 0.0221 5.7 10.360 10.611 2.4 7.511 0.0209 0.0208 -0.5 10.360 9.993 -3.6 8.168 0.0209 0.0218 4.3 10.360 10.483 1.2 8.778 0.0209 0.0218 4.3 10.360 10.478 1.2 9.746 0.0209 0.0216 3.3 10.360 10.370 0.1 T2-1 4.550 0.0105 0.0122 16.2 5.324 6.151 15.6 5.200 0.0105 0.0117 11.4 5.324 5.862 10.1 5.847 0.0105 0.0116 10.5 5.324 5.830 9.5 6.515 0.0105 0.0113 7.6 5.324 5.680 6.7 7.150 0.0105 0.0112 6.7 5.324 5.616 5.5 T2-2 4.550 0.0105 0.0115 9.5 5.324 5.805 9.1 5.200 0.0105 0.0113 7.6 5.324 5.700 7.1 5.847 0.0105 0.0111 5.7 5.324 5.604 5.3 6.515 0.0105 0.0105 0 5.324 5.292 -0.6 7.150 0.0105 0.0105 0 5.324 5.240 -1.5 -
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