连续变截面箱梁主墩0号块复杂受力模式与力学仿真分析

Complex force pattern and mechanical simulation analysis of Block 0 of the main pier of continuous variable section box girder

连续变截面箱梁是钢箱梁桥中应用较多的型式,具有受力复杂、施工变形控制难的特点.依托雄安新区骨干路网京雄高速高碑店连接线白沟河特大桥项目,结合钢箱梁结构异性结构设计理论,采用线性监测、毫米波雷达监测、埋设应变片应力监测与数值仿真分析相结合的方法,获得连续变截面箱梁主墩0号块各项受力变形数据,得到了连续变截面箱梁主墩0号块复杂受力模式的工作机制.结果表明:1)针对线性监测、内应力监测与毫米波雷达监测,提出了连续变截面箱梁主墩0号块控制阀值范围,内应力变化范围为0.71~12.58 MPa,沉降量0.78~-0.2 mm;2)对比分析线性监测与内应力监测数据,并对其进行拟合回归,构建了主墩0号块变形受力模型;3)通过提取主墩0号块毫米波雷达波谱图,获取其变形异常点数据,分析得出了连续变截面箱梁主墩0号块失稳破坏工作机制.上述研究成果可为连续变截面箱梁主墩0号块设计参数优化、主墩施工质量控制与施工工艺优化提供理论支撑与技术指导.

A continuous variable section box girder is the widely used type of steel box girder bridge,which has the characteristics of complex force and difficult construction deformation control.This paper relies on the project of Baigou River Special Bridge on the Jing-Xiong Expressway Gaobeidian link of the backbone road network of Xiongan New Area,in combination with steel box girder structure of the anisotropy structure design theory,the linear monitoring,millimeter wave radar monitoring,stress-strain gauge monitoring and numerical simulation analysis method,toobtain the stress and deformation data of Block 0 of the main pier of continuous variable section box girder,The working mechanism of complex stress mode of Block 0 of the main pier of continuous variable section box girder is obtained.The results for linear monitoring,internal stress monitoring,and millimeter wave radar monitoring,the control threshold range of zero blocks of the main pier of continuous variable section box girder was proposed,the internal stress variation range is 0.71~12.58 MPa,and the settlement amount is 0.78~-0.2 mm;2)the data of linear monitoring and internal stress monitoring were compared and analyzed,and the fitting regression was carried out to construct the deformation stress model of the main pier blocks;3)by extracting the millimeter wave radar spectrum of the main pier zero block and obtaining data on abnormal deformation points,the instability failure mechanism of the main pier zero blocks of continuous variable section box girder was analyzed.The above research results can provide theoretical support and technical guidance for optimization of design parameters,construction quality control,and construction process optimization of Block 0 of the main pier of contionuous variable section box girder.