城市基坑支撑梁爆破拆除安全防护措施探讨

摘要

爆破方法广泛用于拆除基坑工程中钢筋混凝土支撑梁,它显著提高了拆除效率,带来了可观的经济效益和社会效益.但是爆破滋生的诸如爆破振动、爆破飞石和爆破粉尘等有害效应也不容忽视.根据城市大型基坑支撑梁爆破拆除施工经验,研究分析了爆破振动、爆破飞石和爆破粉尘的产生机理,总结了几种常用的安全防护措施.爆破有害效应控制应从"主动控制"和"被动防护"两方面着手.主动控制即从布孔形式、装药结构和起爆网路3个方面优化爆破设计方案,控制爆破有害效应的源头;被动防护即从防护形式和防护材料两方面,最大限度地切断爆破有害效应的传播路径.%Blasting is the main method to demolish reinforced concrete support beam in foundation pit engineer-ing,which improves the demolition efficiency significantly and brings considerable economic and social benefits. However,it also produces many harmful effect which can not be ignored,such as blasting vibration,blasting flyrock and blasting dust.According to explosive demolition experience of large foundation pit engineering in city,mechanism of production of blasting vibration,blasting flyrock and blasting dust are analyzed.Furthermore,few common safety protection methods are compared,harmful effect of blasting demolition should be controlled in two aspects,active con-trol and passive protection.The active control includes holes arrangement and blasting network optimization,and the passive protection includes protection forms and protection material.By using these methods,the source of harmful effect of blasting can be controlled and the travel path of harmful effect of blasting can be cut off.