基于位移与内应力监测的钢桥拱肋受力变形

Forced deformation of arch ribs of steel arch bridge based on displacement and internal stress monitoring

以公路桥梁施工监控技术指南为依据,通过实时监测拱肋各施工阶段下的位移与内应力,研究钢桥拱肋的受力变形规律.结果表明:在不同工况下,钢桥拱肋L/4,3L/4处的竖向位移变化区间为0.30~13.50 mm,L/2处竖向位移变化区间为0.25~11.40 mm,位移方向为竖向向下;在各工况下钢桥拱肋两端拱脚内应力变化范围为6.79~26.53 MPa,L/4,3L/4处内应力变化范围为1.60~27.93 MPa,L/2处内应力变化范围为0.21~11.49 MPa,内应力变化为压应力;全跨拱肋对称位置的受力变形变化趋势保持一致,且在工况2时,吊杆张拉后拱肋整体产生最大位移变化与内应力变化,因此该施工阶段应作为受力变形重点监控工况.研究得出了钢桥拱肋在各工况下不同位置的受力变形规律,其研究成果可为钢桥拱肋的施工与监控提供科学的理论支撑与技术指导.

Based on the technical guide of highway bridge construction monitoring, the deformation laws of arch ribs of steel bridges were investigated through monitoring the displacement and the internal stress of arch rib at each construction stage in real time. The results show that the variation interval of vertical displacement of steel bridge arch rib at L/4 and 3L/4 is from 0.30 to 13.50 mm under different working conditions, and the vertical displacement range of L/2 is from 0.25 to 11.40 mm under different working conditions. The direction of displacement is vertical downward. The stress range of the arch legs at both ends of the steel arch ribs varies from 6.79 to 26.53 MPa under various working conditions, and the variation range of stress at L/4 and 3L/4 is from 1.60 to 27.93 MPa under various working conditions. The stress variation range at L/2 is from 0.21 to 11.49 MPa under various working conditions, and the stress change is compressive stress. The stress deformation change trend of the symmetrical position for the full span arch rib is consistent, and the whole arch rib produces the maximum displacement change and the internal stress change after the suspender is tensioned under the working condition 2.The construction phase can be used as the key monitoring condition of forced deformation.