“Blasting Demolition Design Scheme for the Old Bridge of Quzhou Xi’anmen Bridge Widening and Reconstruction Project”
Passes Expert Review
In August 2017, our company successfully won the bid forthe“Old Bridge Blasting Demolition Construction Project of Quzhou Xi’anmen Bridge Widening and Reconstruction Project.”
The widening and reconstruction project was designed to maintain traffic on the existing bridge while constructing new widened bridges on both sides. After the new bridges on both sides were opened to traffic, the old bridge would be demolished and a new central bridge would be constructed at its original location, ultimately forming an integrated bridge system with the two side bridges.
The old bridge to be demolished was a double-curvature arch bridge with a total length of 346 m, a width of 24 m, seven spans, each spanning 45 m, and six piers. Located in Kecheng District, Quzhou City, the bridge crossed the Qujiang River and was surrounded by a highly complex environment, with the new bridges on both sides closely adjacent and interlaced with the old bridge. Specifically, the distance between the new bridge piers and the old bridge deck was only 1.0 m; the minimum clear distance between the new and old bridge decks was 1.1 m; the closest distance between the new and old bridge piers was 2.55 m. The old bridge piers protruded beyond the old bridge deck and extended approximately 2 m into the deck area of the new bridges on both sides. After completion of the new bridges, water supply, power, and gas pipelines would cross the river through the new bridge structure, with the nearest horizontal distance to the old bridge being approximately 4.45 m.Therefore, the greatest challenge of this project was how to safely carry out the blasting demolition of the old bridge while ensuring the absolute safety of the new bridges and pipeline facilities.To address this challenge, relevant departments of the company organized multiple technical discussions and cooperated with experts from renowned universities to conduct numerical simulation analysis of the bridge structure. The safety impact of the blasting demolition on the new bridges was evaluated, and a scientific, rational, and safe blasting demolition design scheme was developed.
On October 29, an expert review meeting for the “Blasting Demolition Design Scheme for the Old Bridge of Quzhou Xi’anmen Bridge Widening and Reconstruction Project” was held in the conference room of the Xi’anmen Bridge Widening and Reconstruction Project Department. Academician Wang Xuguang of the Chinese Academy of Engineering and renowned blasting expert attended the meeting and served as the leader of the expert panel. Representatives from Quzhou Municipal Public Security Bureau, Port and Shipping Administration, as well as the project owner, design institute, and supervision unit also attended the meeting.After listening to the reports on the blasting demolition scheme and numerical simulation studies, the experts conducted extensive discussions on the design. The expert panel concluded that: “The design scheme is well-founded, comprehensive in content, and reasonable in terms of blasting parameters and initiation network design. The scheme is feasible, and the proposed technical design and protective measures under complex environmental conditions demonstrate a certain level of advancement and scientific value.”
The experts unanimously agreed that the “Blasting Demolition Scheme for the Old Bridge of Quzhou Xi’anmen Bridge Widening and Reconstruction Project” had passed the review.Following the review meeting, the company’s Technical Department revised and improved the scheme according to the expert opinions, while carrying out preparations for construction. The company was ready to commence the project upon receiving the owner’s notice and ensure the successful blasting demolition of the old bridge in accordance with the design requirements.
