大型交通枢纽地下V型柱体系转换变形监测分析--以黄木岗综合交通枢纽工程为例

Deformation Monitoring and Analysis of System Transformation in an Underground V-Shaped Column of a Large Transportation Hub:a Case Study of Huangmugang Comprehensive Transportation Hub

为控制黄木岗综合交通枢纽大倾角V型柱—临时柱转换过程中的结构变形和开裂风险,提出分批转换和分级加卸载的体系转换方法,并采用测量机器人和机器视觉技术对临时柱柱顶、V型柱柱顶和型钢梁跨中位移进行自动化监测和预警。监测结果表明:1)测量机器人和机器视觉监测结果吻合良好,分级加载至临时柱柱顶钢垫块脱开时,临时柱柱顶位移均小于设计给出的3 mm控制值,第3级卸载(总卸载量45%)后临时柱柱顶沉降达到最大沉降量的86%;2)体系转换的影响范围主要为当前跨和相邻跨共3跨范围,型钢梁最大挠度约30.0 mm,小于规范允许值64.0 mm;3)加载阶段框架北侧先于南侧产生向上位移,但22轴南侧V型柱产生最大沉降-3.5 mm,结构产生明显的非对称响应。转换过程结构整体处于安全状态。

A system transformation method is proposed in batches and staged loading and unloading to control the risk of structural deformation and cracking during the system transformation between the V-shaped and temporary columns in the Huangmugang transportation hub.To this end,the measurement robot and computer vision technology are used to automatically monitor the displacement of the temporary column top,V-shaped column top,and steel-concrete beam mid-span for early warning.The monitoring results reveal the following:(1)The measurement robot′s monitoring results agree with those of computer vision.When the steel cushion block atop the temporary column is disengaged following staged loading,the displacement of the temporary column′s top is less than the design-specified control value of 3 mm.Furthermore,after the third unloading stage(45%of the total unloading value),the settlement at the top of the temporary column reaches 86%of its maximum settlement.(2)While the influence range of system transformation primarily comprises the current frame and two adjacent frames,totaling three frames,the maximum deflection of the steel-concrete beam is approximately 30.0 mm,which is less than the allowable value of 64.0 mm.(3)Although the north side of the frame moves upward before the south side during the loading stage,the V-shaped column on the south side of axis 22 still produces a maximum settlement of-3.5 mm,indicating an asymmetric structural response.Therefore,the entire structure is safe during the transformation.