高速跨线天桥爆破拆除预处理过程桥梁结构安全性影响分析OA

Ensuring the stability of the structure after pre-borehole drilling is a common challenge in controlled blasting demolition.This is particularly crucial for overpass bridge demolition,where traffic flow on the underlying roads typically must remain uninterrupted during drilling operations.Therefore,investigating the stability of pre-weakened structures is of significant importance.Based on a case of highway overpass bridge demolition in China,this study employed the finite element software MIDAS to analyze whether the bearing capacity of pre-drilled arch ribs,diagonal braces,and deck positions could satisfy the external load requirements.The results showed that after considering the structural weakening caused by the blast-induced cuts at these respective locations,the minimum safety margin under the most unfavorable load combination during ultimate limit state verification was 33.4%,69.2%,and 7.0%,respectively.These values confirm that the bearing capacity requirements were met.The safety impact analysis conducted helped ensure the successful completion of the bridge blasting demolition.The findings can serve as a valuable reference for similar engineering projects.