外包钢中空混凝土组合桥塔轴压性能试验研究

Experimental Study on Axial Compression Performance of Steel-encased Hollow Concrete Composite Bridge Pylon

摘要:

为研究外包钢中空混凝土组合桥塔的轴压性能，设计、制作了3组试件，分析加劲肋设置形式对破坏模式、荷载-位移曲线、强度及延性的影响。提出一种新型的加劲肋外置型外包钢中空混凝土组合桥塔结构，并结合有限元模型开展应力状态分析和结构稳定性评估。试验结果表明，各试件的破坏模式均为腰鼓型破坏，增设加劲肋能有效提高试件的承载能力和延性，且外置型与内置型加劲肋对承载能力和延性的提升幅度基本相同。仿真结果显示，最不利荷载工况下新型组合桥塔结构各项指标均满足规范要求。新型组合桥塔采用加劲肋外置设计和UHPC永久模板，克服了传统钢-混组合桥塔内部构造复杂导致的施工难题，为保障施工质量提供了新的技术途径。

Abstract:

To study the axial compression performance of steel-encased hollow concrete composite bridge pylon, three sets of specimens are designed and fabricated to analyze the influence of the setting form of stiffening ribs on the failure mode, load-displacement curve, strength and ductility. A new type of steel-encased hollow concrete composite bridge pylon structure externally set with stiffening ribs is proposed, and the stress state analysis and structural stability evaluation are carried out in combination with finite element model. The research results show that the failure mode of each specimen is the waist drum type of failure. Adding stiffening ribs can effectively improve the load-bearing capacity and ductility of specimens. And the increase in load-bearing capacity and ductility of externally set and built-in stiffening ribs is basically the same. The simulation result shows that under the most unfavorable load conditions, all indicators of the new composite bridge pylon structures satisfy the requirements of the specifications. The externally set design of stiffening ribs and UHPC permanent formwork are adopted for the new type of composite bridge pylon to overcome the construction difficulties caused by the complex internal structure of traditional steel-concrete composite bridge pylons, which provides a new technical approach to ensure construction quality.