连续箱梁临时支座预留孔爆破拆除方法

以前 ,采用硫磺砂浆热熔法拆除悬浇箱梁临时支座 ,效果不理想 ,耗时费力。在广珠西线橹尾橇特大桥主桥连续箱梁临时支座的拆除中 ,采用了预留孔的爆破方法 ,破碎效果好 ,拆除速度快。本文介绍了爆破设计的原则、药量计算、炮孔布置、起爆网路和安全措施。此外 ,还介绍了利用PVC管预留炮孔的施工方法

DEMOLITION OF TEMPORARY SUPPORTS FOR CONTINUOUS BOX GIRDER BY BLASTING METHOD WITH PRE-MOLDED HOLES

Formerly,the sulfur-mortar thermal-smelt method was been used in demolition of the temporary supports for a cantilever casting box girder,with poor result.The blasting method with pre-molded holes has been used in demolition of the temporary supports for continuous box girders of main bridge of Luweiqiao XL Bridge located on the western line of Guangzhou-Zhuhai railway,with good result and rapid demolishing speed.In this paper,the principle of blasting design,the calculation of charge mass,the arrangement of pre-molded holes,priming circuit and safety precautions are introduced.In addition,a constructing method for pre-mold of blasting holes with some PVC pipes is presented.