通航航道上千米预应力箱梁桥梁拆除爆破

Demolition blasting of a kilometer pre-stressed box girder bridge on the navigable channel

为了顺利拆除全长1572.44 m,航道上410 m主桥段为国内罕见的“空心桥墩+空心桩基+预应力箱梁”结构的石龟山老桥,通过对比静力切割方法和爆破方法,得出主桥采用静力切割方法拆除施工风险大,拟采用爆破拆除方法。结果表明:采用桥面爆破、桥墩爆破与桩基爆破相结合的施工工艺,以及水压爆破与钻孔爆破相结合的综合技术,主桥桥墩实施水压爆破,箱梁分段解体爆破,采用复式交叉起爆网路和复合防护方式,达到良好的爆破效果,可为类似桥梁的拆除提供了很好的借鉴作用。

In order to successfully demolish the old Shigui Mountain Bridge with a total length of 1572.44 m and a main bridge section of 410 m on the waterway,which is a rare"hollow pier+hollow pile foundation+prestressed box girder"structure in China,by comparing the static cutting method with the blasting method,it is concluded that the static cutting method is risky for the demolition of the main bridge,and blasting demolition method is proposed.The results show that the construction technology of bridge deck blasting is combined with pier blasting and pile foundation blasting,and the comprehensive technology combining hydraulic blasting and borehole blasting are used.The hydraulic blasting and segmented disintegration blasting are used in the piers of the main bridge and the main bridge section respectively,and a double cross detonation network and composite protection methods are used.It provides the very good reference function to the similar bridge blasting demolition.