煤矿巷道相似掏槽爆破技术原理与实验验证

Principles and experimental verification of similar cut-and-fill blasting technology in coal mine tunnels

  • 摘要: 矿山巷道掘进爆破技术是矿山建设和生产的关键技术,掘进断面参数的设计和优化对提高巷道掘进效率和降低成本具有重要意义。其中掏槽参数的设计尤为重要,针对实际的工程中,由于掏槽参数设计的过时,导致爆破效果不够理想的现象。基于均化抵抗线理论对传统掏槽形式进行优化,开发了相似掏槽爆破理论模型,根据实际工程案例中掏槽的面积占比和偏心率设计模型实验,分析了不同掏槽孔形状、面积和位置对巷道掘进爆破效果的影响。研究结果表明:1994—2024年的煤矿岩巷爆破掘进工程案例中,巷道断面面积大部分集中在10 m2 < S≤20 m2,占全部案例的68%。掏槽眼的布置方式主要为方形,占全部案例的71%。随着断面面积增大,掏槽面积在断面中的占比由10.49%下降到4.58%。随着断面高度的增大,偏心率在0≤e < 37.5区间中逐渐增大。在模型实验中,随着空腔面积的增大,试件的峰值应力由145.95 MPa降低到94.79 MPa。空腔偏心率增加,造成试件峰值应力由105.67 MPa上升到130.01 MPa。结合耗散能和分形维数结果可得,空腔占比越大、偏心率越小,试件的结构强度越大、破碎后形成的块度越大。实验证实,当掏槽面积占比B > 10%、偏心率e≤0.1时能够取得较好的爆破效果,验证了相似掏槽理论的正确性。研究结论可用于解决实际工程中掏槽设计不合理而导致爆破掘进效率低等现状。

     

    Abstract: Mine tunneling blasting technology is a key technology in mine construction and production, the design and optimization of the tunneling section parameters are of great significance to improve the tunneling efficiency and reduce costs. The design of the hollowing parameters is particularly important, for the actual project, due to the outdated design of the hollowing parameters, resulting in the phenomenon of unsatisfactory blasting effect. Based on the homogenized resistance line theory to optimize the traditional hollowing form, developed a similar hollowing blasting theoretical model, according to the actual engineering cases of hollowing area ratio and eccentricity design model experiments, analyzed the influence of different hollowing hole shape, area and location on the roadway tunneling blasting effect. The results of the study show that: In the past 30 years, in the cases of coal mine rock tunnel blasting and boring projects, most of the roadway section area is concentrated in 10 m2 < S≤20 m2, accounting for 68% of all cases. The arrangement of the hollowing eyes was predominantly square, accounting for 71% of all cases. As the section area increases, the percentage of hollowed-out area in the section decreases from 10.49% to 4.58%. As the height of the section increases, the eccentricity gradually increases in the interval 0≤e < 37.5. In the modeling experiments, the peak stress of the specimen decreased from 145.95 MPa to 94.79 MPa as the cavity area increased. The increase in cavity eccentricity caused the peak stress of the specimen to increase from 105.67 MPa to 130.01 MPa. Combining the results of dissipation energy and fractal dimension, it can be obtained that the larger the percentage of cavity occupation and the smaller the eccentricity the greater the structural strength of the specimen, and the greater the size of the block formed after crushing. The experiment confirms that better blasting effect can be achieved when the proportion of hollowing area B > 10% and eccentricity e≤0.1, which verifies the correctness of similar hollowing theory. The conclusions of the study can be used to solve the current situation of low efficiency of blasting and digging due to irrational design of hollowing trench in actual projects.

     

/

返回文章
返回