9孔桶形掏槽一次成井技术

 为解决一次成井中天井断面小、深度低的问题,提出9孔桶形掏槽一次成井技术。通过对掏槽爆破机理研究,选取了4空孔掏槽方式,装药孔与空孔直径分别为0.11、0.25m,掏槽孔与空孔间距0.46m等爆破成井主要参数。采用非线性动力分析软件LS-DYNA对9孔桶形掏槽一次成井的关键—掏槽过程进行了数值模拟,实现了9孔桶形掏槽槽腔成形过程的可视化。模拟结果表明,成井参数选取合理,主掏槽孔能与空孔有效贯透形成“莲花形”槽腔,副掏槽孔能以“莲花形”槽腔为自由面进一步扩大槽腔。最后在理论分析和数值模拟基础上,以某露天矿为工程实例,对所取参数进行现场实验,一次爆破形成了23.4m天井,天井断面4m×4m,证明数值模拟结果准确,该技术在深孔一次成井中可行。

Nine-hole Parallel Cutting Technology of the Shaft Excavation in One-step

To solve the problem of the small section and the low altitude in the shaft excavation, the nine-hole parallel cutting technology of the shaft excavation in one-step is proposed in this paper. Firstly, according to the rock failure mechanism in cutting blasting, the main parameters of the shaft excavation are identified. The parallel cutting method works on modes of four empty holes and the diameters of the hole and the empty hole are 0.11m and 0.25m, respectively, and the distance between the cutting hole and the empty hole is 0.46m. Then, the numerical stimulation of the cutting blasting, as the key of the nine-hole parallel cutting mode technology of the shaft excavation, is carried out by the LS-DYNA 3D software and the cavity formation can be visualized. The results of the numerical stimulation show that the parameters are reasonable so that the lotus-shaped cutting cavity can be formed by the main cutting hole blasting and the auxiliary cutting hole can further expand the cavity size. Finally, based on the theoretical analysis and the numerical stimulation and with the engineering case of the shaft excavation by blasting in an open-pit mine in mind, the field experiment is carried out with the selected parameters and a 23. 4m patio is formed with section of 4m×4m. The results of the experiment have verified the accuracy of the numerical stimulation and the feasibility of this technology of the shaft excavation in one-step.