中文摘要：

为研究预应力混凝土梁正常使用状态下变形的随机性,对3片跨度为30m的公路预应力混凝土简支梁进行了足尺模型全过程加载试验。利用蒙特卡罗模拟与非线性有限元方法,建立了混凝土结构非线性变形的随机分析模型,并利用偏序相关系数表示敏感性系数;利用试验统计参数与随机分析模型,对试验梁的跨中挠度进行加载全过程随机分析与敏感性分析,试验结果与随机分析结果的对比,证明了随机分析的必要性与正确性。结果表明：跨中弯矩接近开裂弯矩时,跨中挠度的变异性显著增加;混凝土截面开裂前,混凝土弹性模量的敏感性最大,而当混凝土截面开裂后,张拉控制应力的敏感性最大;在施工中,应尽量降低张拉控制应力的变异性。

英文摘要：

To investigate the random deformation of the in-service prestressed reinforced concrete beam, full-scale loading tests of three prestressed reinforced concrete simply supported beams for highway with the span of 30 m were performed. With Monte-Carlo simulation and nonlinear finite element method, the stochastic analysis model on nonlinear deformation of concrete structures was established. The partial order correlation coefficient was employed as the sensitivity coefficient. The stochastic and sensitivity analysis of the deflection at mid-span in the loading processing were analyzed by test statistical parameter and stochastic analysis model. The comparison between the experimental results and random simulated results verified the necessity and the validity of the stochastic analysis. The results show that the variance of deflection at midspan will increase significantly, when the bending moment of mid-span is close to the cracking moment. Before cracking of the concrete section, the maximum sensitive coefficient is the elastic modulus of concrete. By contrast, after the section cracking, the maximum one is the tension control stress. Variance of the tension control stress should be declined in the construction.