World’s largest-span concrete cable-stayed bridge achieves central span closure

On June 26, the Sejingkat Bridge in Sarawak, Malaysia, built by China Harbour Engineering Company and constructed by CCCC Second Highway Engineering Co Ltd, achieved central span closure, marking a major milestone for the world's largest-span harp-style twin-tower concrete cable-stayed bridge.

Hidden deep within the tropical rainforest, the bridge spans 1,281.2 meters in total length, with towers soaring 119.06 meters high. The central span closure marks the completion of the project's most critical construction phase.

Located in Kuching, the capital of Sarawak, the Sejingkat Bridge is a landmark transport project featuring a twin-tower, double-cable-plane cable-stayed design with a 200m + 400m + 200m main span arrangement. It also incorporates a range of engineering innovations tailored to local geology, climate and traffic conditions.

The bridge features several innovative structural designs. Its main towers adopt a longitudinally separated diamond-shaped design with customized steel tie beams, delivering both structural efficiency and visual appeal. Flexible single-row pile side piers accommodate deformation caused by temperature changes and concrete shrinkage, improving long-term stability and durability.

The bridge adopts an innovative wide single-box concrete girder with an ultra-low height-to-width ratio of 1:10.24, resulting in a slimmer deck and improved driving visibility. Prestressing is used only in the central closure section and cast-in-place side spans, while the remaining girders are non-prestressed, simplifying construction, reducing costs and ensuring structural safety.

The 5-meter-long central closure segment, measuring 25.6 meters wide and 2.5 meters high, was the project's most technically demanding construction phase, requiring exceptional precision. The project team adopted refined, end-to-end management from preparation through post-closure inspection to ensure accurate execution.

To minimize the impact of temperature fluctuations, the team conducted 48 hours of continuous monitoring on the five girder segments adjacent to the closure joint, recording data every two hours to determine the optimal temperature window and ensure precise alignment.

To manage the bridge's 2,000-metric-ton design thrust, the team developed an innovative integrated pushing system and adopted a seven-stage construction method. With coordinated thrust and displacement control, the team achieved balanced structural performance and millimeter-level closure accuracy.

The successful central span closure marks the completion of the bridge's cantilever casting works, paving the way for the final construction phase ahead of its targeted opening in 2026. Deck paving and the installation of auxiliary facilities are now underway.

Once open to traffic, the bridge will strengthen Kuching's transport network, improve regional connectivity and provide new momentum for Sarawak's economic and social development.