在役钢筋混凝土T型梁桥增大截面加固后可靠度研究

Reliability research on structure member strengthening with RC in existing T-beams bridge

针对在役钢筋混凝土T型梁桥增大截面加固前后可靠度研究不足的现状,本文对钢筋混凝土T型梁桥加固后的可靠度进行了研究。利用现有研究成果,结合钢筋混凝土T型梁桥增大截面加固的特点,对作用、抗力进行了研究,建立了T型梁桥加固后功能函数模型。在建立T型梁桥加固后功能函数基础上,结合Monte-Carlo法,计算加固前后的可靠度指标β并进行对比,从可靠度方面对T型梁桥加固效果进行判别,进而寻求较佳加固措施,再对影响结构的可靠度的因素进行了敏感性分析,从而可以找到影响可靠度的关键因素,采取相应措施提高可靠度,为可靠度理论在工程实际中的应用开辟新的道路。利用工程实例对本方提出的方法进行了验证,研究表明,材料强度、结构几何尺寸标准差小时对结构可靠度指标有利,其中材料强度对可靠度指标的影响较敏感。

Aiming at the lack of the reliability research on the existing RC bridge reinforcement,in this paper,the reliability of the reinforced concrete T-beams bridge were studied. The function model of the reinforced bridge were established by studied the action effects and resistance which combined with the existing research results and the characteristics of reinforced concrete T-beams bridge strengthening with RC. The reliability index β before and after reinforcement were calculated and compared,that based on the established functions and the Monte-Carlo method.Thereby,the effect of reinforcement can be judged by the aspects of reliability,and can seeking better reinforcement measures. The sensitivity in effect factors of structural reliability was analyzed,in order to find the key factors which influence the reliability of structure and adopt corresponding measures to improve reliability, reliability theory for application in the engineering practice open up new roads. The methods were validated by a project example and the sensitivity of effect factors of structural reliability were analyzed. Research shows that standard deviation of the strength of the material and geometry size of structure smaller is better for structural reliability index,and standard deviation of material strength influence on reliability index is more sensitive.