高耸桥墩保护性爆破拆除关键技术

为解决高耸钢砼桥墩上部倾斜导致的工程质量不合格问题,采用保护性控制爆破将上部倾斜部分钢砼桥墩予以拆除,同时保留下部未偏斜部分桥墩不受破坏。采用开设组合形状切口,预开定向窗、导向窗;设置组合高差卸荷槽,预伤钢筋弱化抗压抗拉能力为关键措施的控制爆破方案。方案实施取得了十分满意的效果,上部拟拆除部分桥墩顺利倾倒下坠,下部保留部分桥墩完好无损。采用保护性控制爆破技术能高效、安全地解决类似高耸钢砼桥墩(构筑物)部分拆除、部分保留利用的问题,并能取得可观的经济、社会效益。

Key technologies of towering piers protective blasting demolition

In order to solve the problem of unqualified engineering quality caused by the upper tilt of the reinforced concrete bridge pier, the protective controlled blasting was adopted to dismantle its upper inclined part, while keeping the lower qualified part undamaged. Key measures of opening multi-shaped cuts for falling orienting and setting up differential height grooves for pre-damaging steel bars to weaken the compressive and tensile capacities were taken into the controlled blasting scheme. The implementation of the scheme has achieved a very satisfactory effect.The upper part of the bridge pier is removed smoothly, and the lower part remains undamaged. Adopting protective controlled blasting technology can solve the problem of partial demolition and partial utilization of similar reinforced concrete bridge piers(structures), and can obtain considerable economic and social benefits.