摘要
为了提高隧道掘进爆破中炮孔的堵塞效果,利用铝管在爆炸作用下膨胀的特性设计了一种堵孔装置,然后通过动态应变仪测量堵孔装置膨胀撞击钢管的环向应变,通过万能试验机对模拟炮孔中的爆炸堵孔装置进行单轴压缩脱模,通过高速摄影记录水泥墩的爆破过程,从而评估爆炸堵孔装置的堵塞效果。结果表明:钢管在爆炸堵孔装置膨胀撞击下产生的环向应变峰值达到0.02,说明爆炸堵孔装置膨胀冲击孔壁的作用力较大,有利于堵孔装置与孔壁贴合;爆炸堵孔装置与孔壁贴合后的抗压强度为4.1~5.5 MPa,抗剪强度为0.49~0.66 MPa,远大于常规炮泥的抗剪强度(0.09 MPa),其在实际使用中与炮泥配合使用,能有效抑制炮泥运动。采用传统炮泥进行堵塞的水泥墩出现冲孔,爆破后的水泥墩未出现破坏;采用爆炸堵孔装置进行堵塞的水泥墩未出现冲孔,堵孔装置在孔口产生裂纹后才被冲出,爆破后的水泥墩最终裂成三部分。因此,爆炸堵孔装置可大幅改善堵孔效果,从而发挥爆生气体的破岩作用,并有效增强了抛掷作用,对改善隧道掏槽眼的爆破效果具有重要意义。
To improve stemming effectiveness for tunnel excavation and blasting,a stemming device was designed utilizing the expansion characteristics of aluminum tubes under explosive action.The expansion-induced circumferential strain of the stemming device colliding with the steel tube was then measured using a dynamic strain gauge.The simulated explosive stemming devices were subjected to uniaxial compression deformation tests using a universal testing machine.The stemming effects were evaluated by recording the blasting process of cement pillars through high-speed photography.Results showed that the peak circumferential strain of the steel tube under the impact of the stemming device reached 0.02,indicating that the expansion impact force of the device on the blast hole wall was substantial which helped the device adhere to the wall.The compressive strength of the stemming device after adhesion to the blast hole wall was between 4.1 MPa and 5.5 MPa and its shear strength ranged from 0.49 MPa to 0.66 MPa,far greater than the conventional stemming material′s shear strength of 0.09 MPa.In practical use,the stemming device together with the stemming material could effectively prevent its movement.When the traditional stemming material was used for stemming cement pillars,punching phenomenon appeared while no damage was observed after blasting.However,when the stemming device was used instead,there was no punching,and the stemming device only shattered after creating cracks at the collar of the blast hole,resulting in the cement pillar being split into three parts.Therefore,the stemming device significantly improved the stemming effects,and helped increase rock-breaking efficacy of the explosive gas while also enhancing the throwing effect,which is of great significance in improving blasting effects for cut holes.
作者
林谋金
邓小康
张金
薛冰
肖定军
李星
LIN Mou-jin;DENG Xiao-kang;ZHANG Jin;XUE Bing;XIAO Ding-jun;LI Xing(School of Resources and Environment,Southwest University of Science and Technology,Mianyang 621010,China;Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province,Southwest University of Science and Technology,Mianyang 621010,China)
出处
《爆破》
CSCD
北大核心
2023年第2期20-24,共5页
Blasting
基金
国家自然科学基金项目(12172313、11802255)
工程材料与结构冲击振动四川省重点实验室开放基金项目(20kfgk06)。
关键词
地下爆破
堵孔
隧道工程
抗剪强度
爆生气体
爆破效果
underground blasting
stemming
tunnel engineering
shear strength
detonation gas
blasting effect
