大型城市高架桥爆破拆除振动特性

结合拆除爆破测试实例,对城市大型高架桥爆破拆除振动特性及振动波在介质中的传播规律等进行了分析,认为高架桥塌落冲击振动是地下管线及周边建筑物破坏的最主要危险源,使高架桥沿线建(构)筑物产生显著振动影响的只是其附近2³跨桥体触地产生的振动,触地振动影响范围有限,振动主频高于一般地震频率,不易造成周边建(构)筑物产生共振破坏,此外,采取合理的降振防护措施可减小地面及地下防护目标的破坏风险。

VIBRATION CHARACTERISTICS OF LARGE CITY VIADUCT BLASTING DEMOLITION

According to a demolition blasting test example,characteristics and propagation laws of vibration induced by large city viaduct blasting demolition were analyzed.The results showed that the vibration induced by viaduct collapse shock was the main risk source which might make the underground pipelines and buildings surrounding the viaduct damaged.In general,the influence scope of touchdown impact vibration was limited,and only the touchdown vibration induced by 23跨桥体触地产生的振动,触地振动影响范围有限,振动主频高于一般地震频率,不易造成周边建(构)筑物产生共振破坏,此外,采取合理的降振防护措施可减小地面及地下防护目标的破坏风险。According to a demolition blasting test example,characteristics and propagation laws of vibration induced by large city viaduct blasting demolition were analyzed.The results showed that the vibration induced by viaduct collapse shock was the main risk source which might make the underground pipelines and buildings surrounding the viaduct damaged.In general,the influence scope of touchdown impact vibration was limited,and only the touchdown vibration induced by 2³ span bridge body nearby could significantly influenced the surrounding buildings.The vibration frequency was higher than the general seismic frequency,which might be difficult to cause resonance damage to the surrounding buildings.In addition,the reasonable protective measures for vibration reduction were helpful to reduce the damage risk of ground and underground protective target.