Application of Melan Arch Bridges in China

Melan arch refers to a type of concrete arch bridge built by Melan method (embedded arch framework method), which is one of the main types of long-span concrete arch bridges in China. The data of 57 Melan arch bridges built or under construction in China are collected by May 2021, of which the largest span is 600 m. The development process, application status and prospects of Melan arch bridges in China are analyzed, and two typical cases are introduced in this paper. Its development in China can be divided into three stages according to the types of the embedded arch framework used in it. These types of bridges were mainly built as highway bridges in mountainous areas of Southwest China, and its application in railway bridges has increased significantly in recent years. Most of them are deck arch bridges with a catenary curves as arch axes, and their rise-to-span ratios are mainly distributed between 1/4 and 1/6, of which 1/5 is the most. Innovative usage of CFST arch truss as embedded framework enables the economical construction of long-span concrete arch bridge in China; moreover, the usage of “stiff CFST arch truss framework” significantly simplifies the concreting steps. It can be predicted that the average span and quantity of Melan arch will be larger with the continuing technology development of Melan method. Two typical Melan arch bridges under construction are introduced as case studies; one would become the longest span (600 m) arch bridge in the world once completed, and the other is a concrete arch bridge with a span of 510 m.