落花时节入龙游，高能一声送桥友。
新桃旧符终有时，他朝一日再问柳。

--—Prologue

 At 10:00 a.m. on March 15, 2023, the demolition of the old Hutoushan Bridge in Longyou County was successfully completed following the chief commander’s detonation order.

The Hutoushan Bridge was built in 1971 and spans the Qujiang River from south to north, serving as a major transport link between Xiaonanhai Town and downtown Longyou. The bridge features seven 50-meter double-curvature arch spans, with a total length of 408.7 meters and a width of 9 meters.After 52 years of service, the bridge no longer met current structural safety and technical standards. In addition, as a supporting project for Quzhou’s comprehensive transportation hub development initiative—specifically, the “Four-to-Three” upgrade of the Qujiang waterway—the Longyou County Government and relevant authorities decided to demolish and rebuild the Hutoushan Bridge.

At the bridge site, residential buildings are densely distributed within 20 meters of both riverbanks. In addition, on the north bank, there are 10 kV overhead power poles located approximately 8.2 m, 20.7 m, and 67 m from the bridge, respectively, while a reservoir building is located approximately 26.8 m away. On the south bank, several aging and poorly maintained factory buildings are located approximately 25 m from the bridge.A navigable waterway runs beneath the bridge, with a water depth of approximately 10 m, making it impractical to drain the waterway for construction. On both sides of the waterway, approximately 10 m from the bridge, there are four steel-reinforced concrete anti-collision posts, each 12 m high and 1.5 m in diameter.

After being awarded the project, the company attached great importance to the work and immediately assembled a team of technical specialists, senior consultants, and experts. With the objectives of ensuring safe blasting demolition and efficient removal and transportation of blasted debris, the team carefully analyzed and evaluated the proposed design. Based on the structural characteristics of the bridge, the demolition blasting design was developed around four key principles: multiple drilling methods, finely divided initiation zones, precise delay timing using electronic detonators, and comprehensive safety protection.For the arch feet and spandrel walls, 42 mm-diameter shallow holes were drilled, while 90 mm-diameter deep holes were drilled in the bridge piers. The bridge was divided spatially into eight independent blasting zones and temporally into 20 delay zones, with a total delay time of 700 ms. Following the principle of “a tailored approach for each zone,” the blasting parameters and safety protection measures were optimized accordingly.A total of 692 blast holes were drilled, using 1,584 kg of explosives, 800 industrial electronic detonators, and 2,000 m of detonating cord. The blasting, structural breakup, and collapse of the bridge proceeded fully in accordance with the design requirements. Third-party monitoring confirmed that the hazardous effects of the blasting did not pose any safety impact on the surrounding environment. The demolition blasting was therefore completed successfully.

We deeply appreciate that Hutoushan Bridge, the first bridge to span the Qujiang River in Longyou County, carries the memories and emotions of generations of Longyou residents. The recognition and praise we received from the Longyou County Government, public security authorities and other relevant departments, the general contractor, the media, and local residents have been a source of encouragement and, more importantly, a reminder of the responsibility we carry.In the subsequent phase of the project, the company mobilized underwater diamond wire-cutting equipment, deep-water excavation and debris-removal vessels, and specialized teams to fully support the construction of the new bridge. This project represents a breakthrough for the company in integrated urban demolition and construction services, while also demonstrating our strong commitment to corporate social responsibility.