针对大悬臂宽箱梁悬臂板根部容易开裂的问题，以某大悬臂预应力混凝土宽箱梁桥为工程背景，采用 ansys 软件建立精细的空间块体模型，设置9个荷载工况，分析预应力、恒载、偏载、对称活载、正温度梯度、负温度梯度、整体升温、整体降温、收缩变形对结构应力的影响，根据拉应力的分布，总结出各工况抗裂特点，得出对悬臂板根部横向拉应力影响大的主要因素为活载、负温度梯度、收缩变形。%To analyze the problem of cracking resistance of the wide-box-girder bridge with large-cantilever,using a prestressed concrete wide-box-girder bridge with large cantilever,as the research ob-ject,an accurate 3D mass finite element model was built by Ansys software for numerical analysis.9 load cases(prestress load,dead load,partial load,symmetrical live load,positive temperature gradient,neg-ative temperature gradient,the overall heating,the overall cooling and contraction deformation)were ap-plied to analyze the influence on structure stress.According to the distribution of tensile stress,the cracking resistance characteristics of each load case were summarized.The conclusion is that live load, negative temperature gradient and contraction deformation are three main factors on transverse tensile stress appearing in the root of the cantilever.
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