At 7:00 a.m. on November 20, 2021, the blasting demolition of Shuanggang Bridge in Quzhou was successfully completed following the detonation order given by the chief commander.

Shuanggang Bridge in Quzhou was originally built in 1962, with an initial width of just 8.5 meters. In 1997, as part of the reconstruction of the Quzhou–Changshan Highway, the bridge was widened to 23.5 meters, becoming a two-way, four-lane Class I highway bridge with a masonry-and-concrete arch structure and a total length of 209 meters. Following the upgrade, Shuanggang Bridge became an important link connecting the southern part of downtown Quzhou to National Highway 320 to the west, effectively easing east-west traffic congestion in the city. With the continued development of urbanization, however, the existing bridge could no longer cope with the increasing traffic demand, and the government decided to demolish and rebuild it.The bridge was surrounded by a complex environment. Approximately 35 meters to the north, there were shaft wells associated with the construction of underground water pipelines, along with above-ground water pipes; an operational water pipeline was also buried beneath the riverbed. Approximately 40 meters away were overhead national defense fiber-optic cables crossing the river, together with various communication lines. To the west, a concrete water outlet was located approximately 63 meters away in the riverbed, while a residential area was approximately 90 meters away. To the east lay the bustling urban area of Quzhou; Kecheng District People’s Hospital was approximately 175 meters away, and numerous densely packed buildings were located within a 300-meter radius.

The project required the bridge to be demolished by controlled blasting while ensuring the safety of the surrounding environment, thereby facilitating subsequent waterway development and construction of the new bridge. To achieve this, our company developed and implemented a “span-by-span, hole-by-hole precision blasting technique with controlled delay timing.” This approach combined deep-hole and shallow-hole drilling: vertical deep holes were drilled in the bridge piers, while vertical shallow holes were drilled at the arch feet and crown of the main arch ribs to weaken the key load-bearing sections of each span. The resulting blasting effects, including collapse-induced vibration, were strictly controlled within safe limits.A total of 1,050 blast holes were drilled for the demolition, using 2,046 kg of explosives, 1,300 industrial electronic detonators, and 2,000 m of detonating cord. The blasting design comprised 73 delay stages, with a total delay time of 1,507 ms.

As the general contractor, our company was responsible not only for the blasting design and construction, which were successfully completed, but also for supporting municipal works, including building temporary access roads and installing construction barriers. The project therefore represented an effective integration of specialized blasting expertise and municipal construction capabilities, demonstrating the company’s increasingly mature capabilities in integrated construction management.The successful blasting demolition of Shuanggang Bridge received wide recognition from the Quzhou Municipal Government, Quzhou Municipal Bureau of Housing and Urban-Rural Development, Quzhou Municipal Public Security Bureau, Quzhou Municipal Transportation Bureau, Quzhou Municipal Water Resources Bureau, Quzhou Municipal Public Utilities Management and Service Center, and local residents. The project further strengthened the company’s influence in the urban construction sector.