Reliability Analysis of the Crack Spacing for Continuously Reinforted Concrete Pavement(CRCP)
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摘要: 为了确保连续配筋混凝土路面(CRCP) 的耐久性, 需要将其随机变化的横向裂缝间距控制在预期合理的范围内, CRCP配筋设计必须考虑可靠性问题, 根据概率论中求解随机向量函数概率分布的有关定理, 建立了计算CRCP裂缝间距可靠度的直接积分公式, 并与Monte Carlo的计算结果进行了对比。分别考虑裂缝间距超出上、下限两种不同失效模式, 分析了设计参数及其变异系数对CRCP裂缝间距可靠度的影响规律。结果表明CRCP裂缝间距的可靠度主要与设计裂缝间距及参数的变异水平有关, CRCP配筋设计应使设计裂缝间距趋于上限和下限的中值, 保证路面具有尽可能高的可靠度。Abstract: To ensure the service durability of continuously reinforced concrete pavement (CRCP), the transverse crack spacing should be controlled in an expected proper range. The reliability must be considered in CRCP reinforcement design.According to the theorem in probability theory about random vector, the direct integral formula is derived to calculate the reliability of crack spacing, and the result is compared with the one that from Monte Carlo method.The influence of the design variables and their variability coefficients on the reliability is analyzed with the two different failure models.The main factors affected the reliability are the design crack spacing and the variability level.In reinforcement design, the design spacing should be controlled to the medium value between the upper limit and the lower limit of the required spacing.
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Key words:
- CRCP /
- crack spacing /
- reliability /
- direct integral method
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表 1 Gauss-Hermite求积点与求积系数
xi Ai 0.0000000 0.9453087 ±0.9585725 0.3936193 ±2.0201829 0.0199532 表 2 Gauss-Legendre求积点与求积系数
xi Ai 0.0000000 0.5688889 ±0.9061798 0.2362969 ±0.5384693 0.4786287 表 3 直接积分法与Monte Carlo法计算结果对比
σT 直接积分法 2000 4000 6000 2.1 0.69509 0.6950 0.6985 0.7043 2.2 0.85403 0.8515 0.8583 0.8553 2.3 0.94229 0.9430 0.9445 0.9427 2.4 0.98098 0.9790 0.9788 0.9787 2.5 0.99468 0.9960 0.9943 0.9942 2.6 0.99871 0.9995 0.9990 0.9990 表 4 设计裂缝间距相同的三种CRCP结构
路面结构 σT/MPa Ec/MPa εsh hc/cm p/% Ks/MPa·mm-1 ΔT/℃ 结构1 1.89 28000 0.0003 23 0.6 16.8 30 结构2 1.87 30000 0.0004 25 0.5 20.9 20 结构3 3.65 31000 0.0006 27 0.7 36.8 20 注: 其它参数为αc=1.0×105/℃, Ds=14 mm, Es=20000 MPa, αc=9×10-6/℃, r=0.40。 表 5 不同路面结构的失效概率
Cv 结构1 结构2 结构3 0.03 0.9995 0.9995 0.9990 0.06 0.9775 0.9670 0.9395 0.10 0.8795 0.8625 0.8180 0.15 0.7660 0.7415 0.7130 0.20 0.6975 0.6815 0.6515 0.30 0.5910 0.5735 0.5385 -
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