【摘要】 由于川藏地区地质条件复杂，隧道频繁穿越断层破碎带、节理显著发育等地层，导致隧道全断面钻爆开挖的质量难以控制。依托某隧道工程，通过分析斜节理发育全断面隧道钻爆开挖的制约条件和较差的爆破开挖质量，通过现场试验、超欠挖测量和经验公式等方法，提出了该全断面隧道(含仰拱)爆破开挖的炮孔与装药参数优化方法。优化方法包括：全断面分为掏槽区、压炮区、抬炮区和周边区，提出复式楔形掏槽设计、周边长孔与短孔设计和三排抬炮孔与压炮孔设计，减小循环开挖一次进尺长度，依据节理及岩体非均质性条件调整炮孔装药参数等。结果表明：采用优化的爆破方案，隧道全断面轮廓成形较好、爆堆分布合理；即，长孔与短孔设计、周边孔间隔装药可有效控制围岩损伤，减小超挖，复式楔形掏槽可有效控制破碎块石大小，合理的抬炮孔布设可完成仰拱的一次开挖。对比分析发现，优化后最大线性超挖与全断面平均超挖面积减小13.2 cm、1.15 m~2,减小占比30.6%和35.1%,有利于隧道形成高效的循环开挖进度。研究成果可为类似斜节理发育隧道全断面爆破开挖质量控制提供一定的技术支持。更多还原

【Abstract】 Due to the complex geological conditions in the Sichuan-Xizang region, tunnels frequently traverse fault fracture zones and strata with significantly developed joints, making it challenging to control the quality of full-face drilling and blasting excavation in tunnels. Based on a tunnel project, this paper analyzed the constraints and poor blasting and excavation quality of drilling and blasting in full-face tunnels with developed inclined joint. By using methods such as on-site testing, overbreak and underbreak measurement, and empirical formulas, this paper proposed an optimization method for the blasthole and charge parameters of the full-face tunnel(including the invert arch) blasting excavation. The optimization method includes: dividing the full face into cut area, push down blasting area, lift up blasting area, and surrounding area, proposing compound wedge-shaped cut design, surrounding long hole and short hole design, and three-row lift up blasthole and push down blasthole design, reducing the length of each cycle excavation, adjusting the charging parameters of blastholes considering joint and rock mass heterogeneity, etc. The results show that using the optimized blasting scheme, the profile of the full-face tunnel is well-formed, and the fragmentation distribution of blasting stones is ideal. Specifically, the design of long holes and short holes, and the interval charging of perimeter holes can effectively control the damage to surrounding rock, reduce overbreak, and the compound wedge-shaped cut can effectively control the size of fragmented rocks, while the reasonable layout of lift up blastholes can complete the one-time excavation of the inverted arch. Comparative analysis shows that after optimization, the maximum linear overbreak value and the average overbreak area of the full face are reduced by 13.2 cm and 1.15 m~2, respectively, representing reductions of 30.6% and 35.1%, which is conducive to the efficient progress of cyclic excavation in the tunnel. The research results can provide technical and methodological references for the quality control of blasting excavation in full-face tunnels with similar development of inclined joints.更多还原