Key Construction Technology and Monitoring of Long-Span Steel Box Tied Arch Bridge

As a composite system bridge, half-through steel box tied arch bridge combines the arch mainly bearing pressure and the beam mainly bearing bending moment, gives full play to their respective advantages, and has the two characteristics of large span capacity of arch bridge and strong adaptability of simply supported beam bridge to foundation. However, in the construction process, due to the complex construction technology and structural stress behavior, the hoisting of arch rib, the tensioning of tie rod and suspender are accompanied by the change of internal load, which is a challenge for bridge construction. Taking the Lancang River Liming Bridge in Xishuangbanna, Yunnan Province as an example, this paper introduces a new construction scheme of arch bridge, introduces the structural characteristics of cable hoisting system, and puts forward the construction monitoring method. The response of arch rib, suspender, tie rod and main beam is monitored by health monitoring system and compared with the analysis results of finite element model to ensure that the stress and deformation of the structure under various working conditions are in a reasonable state. The results show that the proposed construction scheme can meet the safety and quality requirements of bridge construction, and the finite element model can reasonably predict the bridge behavior in construction. This study is expected to promote the construction of long-span half through steel box tied arch bridge.