1160m长城市高架桥爆破拆除

摘要

The explosive demolition of Sanhua viaduct is conducted by in situ controlled blasting technology.This article mainly introduces the height of pier,hole arrangement,blasting network and safety protection methods.The blasting vibration is monitored and analyzed briefly.The failure height of single pier column is 1.02~4.54 m.The specific charge of the pier are 1.00 kg/m3,1.43 kg/m3 and 1.93 kg/m2 for top,middle and bottom parts,respectively.The mixing trapezoid,quincunx and single-row holes arrangement are applied on cylindrical structures to overcome the influence of arc curve of column structure on the burden line,which avoids losing control of the resistance line.The millisecond delay initiation was used to blast the viaduct each span by span.The 4 layers protective means including geogrid,safety nets,bamboo raft,and sunscreen net are chosen to avoid the flyrock and shock wave damages.%采用原地坍塌爆破技术对散花高架桥主体部分成功地进行了控制爆破拆除.重点介绍了桥墩炸高、布孔方式、爆破网路、安全防护措施.对爆破振动进行了监测,并做了简要分析.单个桥墩墩柱的破坏高度在1.02~4.54 m之间.桥墩墩柱上中下三部分炸药单耗分别取1.00 kg/m3、1.43 kg/m3、1.93 kg/m3,采用梯形、梅花形及单排混合布孔方式,克服了柱状构筑物圆弧曲面对抵抗线的影响,避免了抵抗线失控.采用毫秒延时控制爆破技术,逐跨分段起爆.采用土工格栅、安全网、竹排架、防晒网4层立体防护措施防止飞石和冲击波造成的危害.