腹板裂缝是预应力混凝土连续箱梁桥的主要病害之一，但目前相关的研究较少，为此，文中依据某等截面预应力混凝土连续箱梁桥的病害检测结果， 采用有限元软件ANSYS 对比了不同厚度的梁桥腹板的主拉应力，分析裂缝产生的原因，并采用外贴钢板、环氧树脂封闭等加固措施对连续箱梁桥进行加固和跟踪检测．结果表明: 腹板裂缝的出现与腹板厚度及腹板所配腹筋有关，这进一步验证了腹板厚度应大于60cm 的观点; 加固后腹板裂缝的宽度和长度均未出现扩展和新增现象，表明该加固方法可有效控制腹板斜裂缝的扩展，该加固方案是可行和有效的．

On web crack,one of the major problems existing in pre- stressed concrete continuous box- beam bridges,few studies have been conducted.In this paper,according to the monitoring results of a continuous box- beam bridge with constant cross- section,the major tensile stresses in the web with different thickness were discussed withthe finite element software ANSYS,and the causes of cracks were analyzed.Moreover,some reinforcement mea-sures such as employing steel plate and sealing epoxy resin were taken,and the reinforcement effect was finally con-firmed by observations. The results show that the crack is greatly related to the web thickness and the web steel,so that the web thickness should be larger than 60cm; and that,after the reinforcement,there is no crack propagation and appearance in width and length directions,which means that the proposed reinforcement measures can effec-tively control further development of diagonal cracks of web and possess high feasibility and effectiveness.