Research on Track Alignment Measurement Technology of Road-rail Long Span Bridge in Operation Period.

TAN Shehui; XU Weichang; YANG Xingwang; JIN Chengming

The Shanghai-Suzhou-Nantong Yangtze River Bridge is China's first long-span cable-stayed road-rail bridge. The bridge structure is complex and monitoring is difficult. Combined with the structural characteristics of the Shanghai-Suzhou-Nantong Yangtze River Bridge, new CP III repair methods are continuously tried, and after long-term track alignment deformation monitoring practice, CP III remeasurement and track alignment measurement methods suitable for long-span highway-railway bridges are obtained. The research shows that: CP II measurement adopts fourth-grade conductors for monitoring, which meets the corresponding accuracy index; CP III plane measurement is still conducted by free station method with two pairs of stable CP II points at both ends of the long-span bridge for highway and railway as the starting points for calculation. A pair of datum points are added on the piers of the main tower, and the two are used together as the starting points for CP III plane measurement. Because the bridge is affected by temperature, wind, load and other factors at all times, the CP III elevation measurement adopts the precision leveling method. According to the analysis of the effective detection bands for the three chord lengths of 10 m, 30 m and 60 m, the misjudgment rate of 5 mm deviation of 10 m and 30 m strings is 0; the misjudgment rate of 5 mm deviation of 60 m string is less than 8%, and the misjudgment rate of 8mm deviation is less than 1%. According to the comprehensive comparative analysis of the error rate of effective detection band deviation and the implementation efficiency of the measurement trolley, it can be seen that the single-point constraint measurement method based on the inertial navigation trolley is more suitable for the alignment measurement of the long-span bridge track for both road and rail during the operation period.

Railway Standard Design, 2023, Vol 67, Issue 9, p56

1004-2954

Academic Journal

10.13238/j.issn.1004-2954.202201170002