复杂环境条件下的路堑开挖爆破

待开挖的路堑临近大型变电站 ,路堑上空有 80余条高压线 ,地下有多处输水管与路堑交叉。在这样复杂环境条件下进行路堑开挖爆破 ,采取了超钻预裂爆破、主爆孔底部留置不装药空腔和不耦合装药、选用低爆速低威力炸药、微差起爆控制单响药量等技术措施 ,有效地降低了爆破震动 ,保证了边坡成型和稳定。此外 ,采用细土、草袋等材料加强覆盖 ,保证堵塞长度和堵塞质量 ,有效地控制了飞石。由于爆区范围内存在较强的电场和磁场 ,采用了非电起爆技术 ,避免了杂散电流的影响 ,保证了爆破作业的安全。

CUT EXCAVATION BLASTING IN COMPLEX ENVIRONMENTAL CONDITIONS

The cut to be excavated lies close to a large-scale transformer station.There are high voltage wires of more than 80 over the cut and several underground water pipes crossing with the cut.For cut excavation blasting in so complex environmental conditions,such technological measures as using the presplitting blasting with subdrilling,retaining the uncharged chamber at bottom of main blastholes,performing the uncouple charging,adopting the low-strength explosive and controlling charge weight per delay interval by the short-delay firing were used to reduce the blasting vibration effectively,thus ensuring the formation and stability of cut slope.In addition,the covering was strengthened by use of such materials as fine earth and straw bag,and the length and quality of stemming were guaranteed,controlling the flying rocks effectively.Because the electric and magnetic fields exist within the blasting area,the nonelectric initiation technology was used to avoid the effect of stray current,ensuring the safety of blasting operation.