连续梁拱桥拱脚抗裂控制及监测技术研究

Research on Crack Resistance Control and Monitoring Technology for Arch Feet of Continuous Beam Arch Bridges

连续梁拱拱脚是拱肋架设施工的基础及前提,但系杆拱拱脚混凝土在施工过程中极易出现混凝土结构性裂缝,影响结构安全。依托荆荆铁路江汉运河特大桥(74+160+74)m连续梁拱桥,对拱脚关键部位施工抗裂性主动控制及信息化监测进行了重点研究,通过优化混凝土的配合比、减少水泥用量、掺加添加剂、优化材料用量等措施,进行多次对比试验,并采用信息化监测手段对拱肋的线形、内力等进行动态监测,以确保拱肋的施工质量满足施工及设计要求,可以有效降低混凝土结构裂缝的产生,延长桥梁使用寿命,可为工程实践提供指导和借鉴。

The continuous beam arch foot is the foundation and prerequisite for the construction of arch ribs,but the concrete of the tied arch foot is prone to structural cracks during the construction process,which affects structural safety.Based on the continuous beam arch bridge of the Jianghan Canal Extra Large Bridge on the Jingjing Railway(74+160+74)m,this study focuses on the active control and information monitoring of the construction crack resistance of key parts of the arch foot.Through measures such as optimizing the concrete mix ratio,reducing cement consumption,adding additives,and optimizing material consumption,multiple comparative tests were conducted,and information monitoring methods were used to dynamically monitor the linearity and internal force of the arch ribs to ensure that the construction quality of the arch ribs meets the requirements of construction and design.This can effectively reduce the occurrence of concrete structural cracks and extend the service life of the bridge,providing guidance and reference for engineering practice.