基于拉索损伤的预应力混凝土斜拉桥静力性能退化机理

杨广军¹，魏忠国¹，牟苏²，姜作仟¹，宋涛³

1.山东省公路桥梁建设集团有限公司，山东 济南  250021；2.济南城建集团有限公司，山东 济南  250013；

3.山东交通学院土建工程学院，山东 济南  250357

摘要：为研究拉索损伤后预应力混凝土斜拉桥静力性能退化机理，将斜拉索等效为弹性支承，以等效三跨连续梁为基本结构，建立拉索损伤后索力、主梁弯矩及挠度退化模型，推导拉索损伤后斜拉桥的静力性能退化规律的解析表达式，将计算结果与采用有限单元方法（finite element method，FEM）计算结果进行对比。研究结果表明：本文推导的模型理论计算结果与采用FEM计算结果高度吻合，验证本文提出的模型的有效性和精确性，可用于评估拉索损伤后预应力混凝土斜拉桥的静力性能。

关键词：斜拉桥；静力性能；退化机理；拉索损伤；预应力

Mechanism of static performance degradation of prestressed concrete cable-stayed bridges based on cable damage

YANG Guangjun¹, WEI Zhongguo¹, MOU Su², JIANG Zuoqian¹, SONG Tao³

1. Shandong Road & Bridge Construction Group Co., Ltd., Jinan 250021, China; 

2. Jinan Urban Construction Group Co., Ltd., Jinan 250013, China; 

3. School of Civil Engineering, Shandong Jiaotong University, Jinan 250357, China

Abstract: To study the degradation mechanism of the static performance of prestressed concrete cable-stayed bridges after cable damage, the stay cables are equivalent to elastic supports, and an equivalent three-span continuous beam is established as the basic structure. A degradation model for cable force, main beam bending moment, and deflection after cable damage is developed, and analytical expressions for the degradation laws of the static performance of cable-stayed bridges after cable damage are derived. The computational results are compared with those obtained using the finite element method (FEM). The research results indicate that the theoretical computational results derived from the model are in high agreement with those obtained using FEM, validating the effectiveness and accuracy of the proposed model, which can be used to assess the static performance of prestressed concrete cable-stayed bridges after cable damage.

Keywords: cable-stayed bridge; static performance; degradation mechanism; cable damage; prestressing force