The South-North Water Diversion Bridge | China

Project Description

South Second Ring Road West Extension Bridge Project

The South Second Ring Road West Extension Bridge over the South-to-North Water Diversion Project is a major municipal bridge featuring a steel–concrete composite arch structure, designed to meet high requirements for strength, durability, and structural efficiency.

Structural System

The main structure is constructed with C50 concrete, ensuring high compressive strength and long-term performance. The primary load-bearing elements are dumbbell-shaped steel–concrete composite arch ribs, formed by two Ø1100 mm steel tubes with a wall thickness of 14 mm and a section height of 2.6 meters.

The two main arch ribs are interconnected by steel webs, forming an integral truss system. To enhance composite action and structural stability, C40 micro-expansion concrete is cast inside the steel tubes.

Geometric Characteristics

The arch ribs are designed as spatial curved structures, with a longitudinal span of 126.28 meters. The center-to-center distance between the two arch ribs is 14.7 meters, while the vertical distance from the highest point of the arch rib center to the main girder centerline is 25.256 meters, reflecting the bridge’s large-span arch profile and efficient force distribution.

Engineering Significance

This project demonstrates advanced application of large-diameter steel tube composite arch technology, high-performance concrete, and spatial arch geometry, making it a representative example of modern municipal bridge engineering over critical infrastructure corridors.