钢筋混凝土偏心受压柱长期变形随机分析

混凝土收缩徐变具有显著的不确定性，需要采用随机方法进行有概率保证意义的长期变形分析.采用基于响应面的蒙特卡洛抽样技术，将GL2000模型中影响混凝土结构长期变形的因素作为随机变量，建立了混凝土结构的长期变形随机性分析模型.利用该模型进行了钢筋混凝土偏心受压柱长期变形随机分析，并考察了混凝土抗拉强度对长期变形的影响.在算例中，当偏心率接近1.0时，抗拉强度的敏感性系数达到峰值0.6，然后逐渐降低；当偏心率为1.6时，抗拉强度的敏感性系数基本为0.分析结果表明，钢筋混凝土柱开裂前，混凝土抗拉强度对其长期变形没有影响；随着偏心率的增大，混凝土开裂程度加深，其对长期变形的影响逐渐增大至峰值而后逐渐减小. 

Long-Term Random Deflection of Eccentrically Loaded RC Column

Owing to the randomness of shrinkage and creep of concrete, random analysis method should be adopted to provide probabilistic guarantee for the analysis of concrete long-term random deflection. Stochastic variables for the long-term analysis with GL2000 model about creep and shrinkage of concrete were presented. Combining Monte Carlo sampling with the response surface method, the stochastic analysis model was established, which is on time-variant deflection of concrete structure. The long-term deflection of reinforce concrete (RC) columns were analyzed using this model. The influences of tensile strength of concrete on long-term deflection of RC columns were considered. The case study shows that when eccentricity ratio is increased to 1.0, the sensitivity of tensile strength reaches a peak of near 0.6 and then decreases gradually. Afterwards, when eccentricity ratio is 1.6, the sensitivity value is reduced to zero. The tensile strength of concrete has no effect on long-term deflection of columns prior to the crack of concrete. With the increase of eccentricity ratio, the effects of tensile strength of concrete will grow to peak and drop down gradually.