深孔爆破技术在不规则台阶中的应用

为了解决废弃矿区垦造水田工程,存在采矿遗留高度3～10 m不规则台阶的问题。且因为工期紧,对这些不规则台阶不能采取浅孔台阶爆破和深孔爆破相结合的方式施工。同时,低台阶开挖采取大于50 mm孔径爆破施工缺少理论依据,工程案例也较少。为此,根据以往经验和参考多边界石方爆破药量计算原理并结合现有钻孔设备,对不规则台阶采取梅花形布孔,用φ90 mm钻机钻孔,其中钻机无法打孔的局部位置在其后侧加密倾斜孔。采取多排深孔延时爆破技术,累计14 h一次性施工。因已购非电雷管段别有限,则利用现有雷管组网,采取分区接力的起爆网路,一次性成功爆破了高低不平的不规则台阶,除了爆堆表层2 m左右范围内有大石块,其余位置岩石破碎块度较小,爆破后无根底,达到预期效果,为后续工作创造了有利条件。

Application of deep-hole blasting technology in irregular bench

The paddy field project in the abandoned mining area has irregular bench with a height of 3-10 meters. Because of the tight construction period, it is not allowed to adopt the method of combination of short-hole blasting and deep-hole blasting to these irregular benches. In addition, there is a lack of theoretical basis and fewer engineering cases for the construction of the short bench with an aperture of more than 50 mm. Therefore, based on the past experience and reference to the principle of charge amount calculation in multilateral boundary rock and combined with existing drilling equipment, the irregular benches are taken to be drilled by a φ90 mm drilling machine, and the local position where the drilling machine can't be drilled is encrypted in the back side of the slope hole. This blasting project, a total of 14 hours one-off construction,adopt the multi-row bore millisecond deep-hole blasting. Due to the restriction segments of non-electric detonators which have been purchased, the existing detonator network is used to form firing circuit being partitioned and relayed. The irregular benches are successfully destroyed at one time, except for the large stone within 2 m of the surface layer of the explosion. In the rest of the block, the bottom is fairly flat after blasting, which achieves the expected effect and creates favorable conditions for the follow-up work.