复杂环境下危桥控制爆破拆除

Explosive Demolition of Unsafe Bridge in Complex Environment

位于仙桃老里仁口的通顺河公路桥多处出现裂痕,中间一跨采用钢结构进行了加固,大桥已不能满足安全使用、交通畅通的要求;大桥两端距离民房最近只有2 m,环境十分复杂,决定采用原地坍塌的爆破方案进行拆除。为确保周边房屋等建筑设施的安全,爆破部位主要设置在爪型桥墩和连系梁,采用刚性防护与柔性防护相结合的方式进行覆盖防护和近体防护,配合以爆破震动测试。起爆后,大桥按设计原地塌落,飞石均在10 m范围以内,爆破振动速度均小于爆破安全规程的标准。

The Lao Li Ren Kou Tongxun Rriver Hhighway Bbridge located in Xiantao city appeared many cracks,and the bridge has been reinforced in the middle span with steel structure. It couldn＇t meet the safe usage and smooth traffic requirements. The smallest distance between the brick buildings and the end of the bridge was only 2 m. In order to ensure the safety of the surroundings,the blast site was mainly arranged at the bridge piers. The piers and beams were covered with bamboo spring board and safety nets,at the same time,the blasting vibration test was taken into account. The blasting results show that the construction demolition agreed with in-situ collapse design well,and the fly rocks were controlled within 10 m,and the blasting vibration was lower than the standard of state regulations.