Recently, a breakthrough was achieved on a key control node for Section B of the Phase II Huandeng Road Project in the Xiamen New Airport Area, undertaken by The Sixth Engineering (Xiamen) Co., Ltd. of CCCC Third Harbor Engineering Co., Ltd.: the casting of all cast-in-place box girders for Bridge No. 9 has been completed, marking the completion of the bridge's main structure.

As an important supporting transportation project for the Xiamen New Airport Area, the Phase II Huandeng Road Project will further improve the road network structure of the area. The constructed Bridge No. 9 is located at the southernmost point of Dadeng Island and is a crucial project for ensuring the continuous alignment of Huandeng Road. Most of the bridge is situated over the sea, close to sea level, and is characterized by low clearance and shallow girder depth. These features demand high standards of construction precision, quality, and safety, leading to its designation as a key controlling project within the section. Furthermore, the bridge intersects significantly with the existing rock-fill zone of the revetment structure, which posed substantial challenges for the construction of the cast-in-place box girder falsework.

The project team brainstormed ideas and established a research task force. Giving full consideration to the specific characteristics of the riprap layer and seabed strata at the bridge site, they implemented targeted structural optimization measures concerning the overall falsework design, material configuration, and structural stress analysis. The team innovatively proposed a steel pipe Bailey support system without intermediate temporary piers. This system primarily consists of spreader beams, anchor bearing beams, steel pipe columns, sand jacks, transverse load-bearing beams, reinforced Bailey girder longitudinal beams, and I14 small distribution beams. The Bailey girders are arranged longitudinally in a single span, with the maximum span reaching 25 meters. This support system enables a single-span falsework structure without intermediate temporary piers, making it suitable for the box girder construction requirements over the riprap layer.

The task force also researched and designed a steel pipe column foundation structure for the submerged pile cap. This effectively resolved the technical issue where the pile cap dimensions were insufficient to meet the support requirements for the steel pipe columns and to withstand the unbalanced loads generated during the box girder casting process.

Currently, Bridge No. 9 has officially moved into the bridge deck system construction phase. The project team will efficiently advance the subsequent work sequences. Upon its completion and opening to traffic, this project will further enhance the traffic network in the Xiamen New Airport Area, providing strong support for regional resource development and industrial agglomeration. (Content by: Zheng Xuechao)