桥梁工程中，面对日益艰巨的钢筋混凝土危旧桥梁检测加固任务，急需寻求一种快速、有效，可靠的检测加固方法以便解决面临的难题。本文提出在桥梁检测过程中根据梁体受拉区竖向弯拉裂缝高度快速评估桥梁承载能力的方法。对于检测中发现的承载力达不到要求的桥梁采用碳纤维加固混凝土结构技术进行加固。 本文依托黄陵—李章河铁路桥梁检测加固工程，对碳纤维布加固混凝土结构技术应用于桥梁加固领域的关键技术进行了深入的研究，主要研究内容包括： 1、在桥梁运营过程中，钢筋混凝土T形梁竖向弯拉裂缝开展是造成梁体承载力下降的主要因素之一。将钢筋混凝土T形梁受弯全过程分为四个阶段(梁体开裂前阶段、梁体开裂阶段、压区混凝土处于弹塑性阶段和极限阶段)，应用弹性理论对其受弯全过程进行分析。推导出各个阶段的受压区高度方程，通过求解得到受压区高度的数值解。将钢筋混凝土T形梁带裂缝工作分为三个阶段(梁体开裂阶段、压区混凝土处于弹塑性阶段和极限阶段)，推导出各个阶段裂缝高度与受压区高度关系式，结合受压区高度的数值解，计算出裂缝高度值。 2、在钢筋混凝土T形梁受弯全过程分析的基础上，推导出梁体开裂后抗弯承载力—受压区高度的关系式，结合已推导的裂缝高度与受压区高度关系，建立起梁体抗弯承载力—裂缝高度的理论关系，来快速评估梁体承载能力。 3、通过对钢筋混凝土T形梁使用阶段的受力分析，考虑到结构二次受力，在确定加固梁极限承载力的基础上，建立加固梁抗弯极限承载力与所需要粘贴的碳纤维布层数的关系式。 4、将本文的研究成果应用于黄陵—李章河铁路桥梁检测加固工程中。加固后经有限元模拟验算以及做现场动荷载试验，验证本文研究成果的可行性及可靠性。

In bridge engineering, it has an urgent need to inspect and strengthen many of these bridges with a fast, effective and reliable method. In this paper, the assessment methods of bridge carrying capacity which make use of vertical flexural tension cracks are presented. For the inspection fail to meet requirements of the carrying capacity of bridge need to be reinforced by externally bonded carbon fiber reinforced polymer (CFRP) sheet technique. Combining with the research program ‘Huangling-Lizhang river inspection and strengthen project of the railway bridge, the key techniques of application of CFRP composite to strengthen reinforced concrete bridges are studied. The major contents are mainly summarized as follow: 1. Vertical flexural tension cracks in reinforced concrete T-beams are the one of the main factors of flexural-capacity decline of beams for in-service bridges. The complete flexural-course of the reinforced concrete T-beams is divided into four stages, that is, before cracking stage, cracking stage and elastic-plastic stage, limit stage of compression zone of reinforced concrete. The complete flexural-course of the reinforced concrete T-beams were analyzed by application of the theory of elasticity. On this basis, the equation of compression zone height of concrete in the four stages was presented. Numerical solution of compression zone height of concrete was solved. The reinforced concrete T-beams cracked in work is divided into three stages that cracking stage and elastic-plastic stage, limit stage of compression zone of reinforced concrete. The relationship with the crack height and compression zone height of concrete in the three stages were presented. Crack height was calculated by numerical solutions of compression zone height of concrete. 2. Based on analysis of the complete flexural-course of the reinforced concrete T-beams, the relationship with the compression zone height and ultimate flexural-capacity of concrete after crack was presented. The relationship of ultimate flexural-capacity and crack height was established to assessment of bridge capacity. 3. Through force analysis of the reinforced concrete T-beam in phase of the normal, taking into account the structure of the second-loading. Based on determining the ultimate flexural-capacity of CFRP strengthened beams, the relationship of the ultimate flexural-capacity and CFRP layers of CFRP strengthened beams was established. 4. Apply the results of this paper to ‘Huangling-Lizhang river inspection and strengthen project of the railway bridge’. After reinforced by ANSYS simulation and do Dynamic Load Test of strengthen bridge, verify the feasibility and reliability of research results in this paper.