避免山岭隧道爆破超挖与欠挖的优化方法及应用

Optimization Methods and Application for Over Excavation and Under Excavation Control in Mountain Tunnel Blasting

针对襄阳-荆门高速铁路徐高岭隧道施工过程中出现的超、欠挖问题,采用三维数值模拟方法研究了爆破方案中最小抵抗线、辅助眼间距及周边眼间距等对爆破施工质量的影响规律。在原爆破参数优化分析的基础上,基于最小化平均线性超、欠挖量,确定了优化后的爆破参数。通过三维激光扫描技术对优化爆破参数后的施工质量进行了综合评价。结果表明:当最小抵抗线从60 cm增加到75 cm时,平均线性超挖减少了约63.6%;当周边眼间距从40 cm增加到55 cm时,平均线性超挖减少了约77.8%;当辅助眼间距从90 cm增加到105 cm时,平均线性超挖仅减少了20.0%。采用优化后的爆破参数进行施工,三维激光扫描所得平均线性超挖与欠挖分别控制在8 cm与4 cm之内。爆破方法优化后,开挖与设计轮廓线吻合良好,实现了爆破施工质量的有效控制;现场爆破施工质量良好,避免了大面积的超、欠挖问题。

In response to the problems of over excavation and under excavation during the construction of Xugaoling Tunnel on Xiangyang-Jingmen high-speed railway,3D numerical simulation technology was used to explore the impact of the minimum resistance line,auxiliary hole,and perimeter hole spacing on the quality of blasting construction in the blasting plan.Based on the optimization analysis of the original blasting parameters,the optimized blasting parameters were determined by minimizing the average linear over excavation and under excavation.Subsequently,a comprehensive evaluation of the construction quality using optimized blasting parameters was conducted through 3D laser scanning technology.The results indicate that when the minimum resistance line increases from 60 cm to 75 cm,the amount of over excavation decreases by about 63.6%.When the perimeter hole spacing increases from 40 cm to 55 cm,the amount of over excavation decreases by about 77.8%.When the auxiliary hole spacing increases from 90 cm to 105 cm,the amount of over excavation only decreases by 20.0%.Using optimized blasting parameters for construction,the average linear over excavation and under excavation obtained from 3D laser scanning are controlled within 8 cm and 4 cm,respectively.The excavation and design contour lines match well,achieving effective control of the quality of blasting construction.The optimized on-site blasting construction quality is excellent,avoiding the problem of large-scale over excavation and under excavation.