The Xiaogan No. 2 Bridge project is the second important inter-island passage between Zhoushan Island and Xiaogan Island. The route starts from the planned southern ring road of Xiaogan Island, intersecting with the planned south bank's 7th latitude road, 3rd latitude road, and northern ring road from south to north. It crosses the Shenjiamen waterway, with the north bank intersecting with Haijing Road, planned North Road 1, North Road 2, North Road 3, and Haitian Avenue. It is a self-anchored suspension bridge with three spans and double towers, with a span arrangement of 150m + 370m + 150m = 670m, where the standard beam section is 616m long, 3m high, and 32m wide. The main bridge has a longitudinal slope of 2.49%, with a vertical curve of R = 2500m at the mid-span, and a vertical curve of R = 10000m between the main approach bridges; the entire bridge has a transverse slope of 2%.

The project experienced ignition and commencement on January 15, 2016, the start of the first board unit manufacturing on March 3, the commencement of the first longitudinal beam on April 7, and the assembly of the first group of standard segments on April 26. By June 18, the assembly of the A0N segment bridge position in the anchorage area on the island side began, with strict quality control throughout to ensure project quality.

On May 19, 2016, the Zhoushan Quality Inspection Station sent personnel to randomly inspect the processing and manufacturing project of the Xiaogan No. 2 Bridge, fully affirming the construction quality of the project.

As an important bridge project in Zhoushan City, the welding requirements for the bridge body far exceed our company's previous welding standards for ship projects, with all weld inspection rates needing to reach 100%. Additionally, since this is our company's first undertaking of bridge steel structure manufacturing, there was a lack of experience and technology, leading to continuous doubts from the owner, supervisor, and China Communications Second Navigation Engineering Bureau at the beginning of construction. Whether we could successfully process and manufacture, and whether the quality would meet standards, were challenges faced by Changhong personnel. However, once the inspection results came out, all doubts were shattered.

Currently, with the support of the company leadership, the bridge project team has entered a stable production phase, having completed one-third of the standard segments for the entire bridge, with quality under control and receiving unanimous praise from the Wuhan bridge supervision. The single pass qualification rate for all welds has reached 96%, and the three-inspection qualification rate has reached 100%.

It is understood that the biggest construction difficulty of this bridge lies in the anchorage area of the main cable and the overall hoisting operation of the standard segments. The anchorage area mainly refers to the overall beam segments related to the main cable entering the beam, diverging, and anchoring. The structure of the beam segments in this area is complex, and based on the on-site construction conditions, directly assembling them on-site is the most effective method. The precision requirements during construction layout in the anchorage area are particularly important due to its complex structure.

To ensure that shipping is not affected during the construction process, a temporary navigation hole is set in the mid-span. Combining hoisting and shipping capabilities, the project team optimized the hoisting plan for the main beam standard segment length of 16m in the navigation hole area to 64m and 58m, meaning that four standard beam segments are spliced together before leaving the factory, and then a 600-ton floating crane will perform the overall hoisting after the bridge position is shipped.

Although this is our company's first bridge project, and the difficulty and quality requirements are higher than those of other similar bridges, the steady progress of the bridge processing and manufacturing will accumulate valuable experience for us in undertaking large-tonnage bridge processing and large segment overall closure in the future.