空孔作用下定向涨裂破岩试验研究

Experimental research on directional fracturing and rockbreaking under action of holes

为了深入研究空孔作用下岩石定向涨裂机理,开展不同空孔距离及数量下的定向涨裂破岩试验,分析对岩石裂纹扩展及涨裂压力的影响规律。研究结果表明:空孔存在时可定向引导涨裂裂纹扩展并明显减小涨裂压力;随着空孔距离增大,空孔定向引导裂纹方向能力越来越差,最大涨裂压力逐渐增大,当空孔距离由200 mm增至250 mm时,最大涨裂压力的最大变化率为13.8%;随着空孔数量增加,主裂纹线性增加,但裂纹扩展方向线性度越来越差,最大涨裂压力逐渐减小,当空孔数量由2个增至3个时,最大涨裂压力的最大变化率为16.3%。通过试验直接证明了空孔定向涨裂破岩的可行性。

In order to study the mechanism of directional fracturing and rock breaking under the action of holes,the experiments of rock directional fracturing at different distances and quantities of holes were carried out,the influence rules of rock crack propagation and fracturing pressure were summarized and analyzed.The results show that holes can guide the crack propagation and reduce fracturing pressure.With the increase of the holes distance,the ability of the hole to guide the crack direction becomes worse,and the maximum fracturing pressure gradually increases.When the distance of the holes increases from 200 mm to 250 mm,the maximum fracturing pressure change rate is 13.8%.With the increase of the number of holes,the main crack increased linearly,but the linearity of crack propagation direction became worse and worse,and the maximum fracturing pressure gradually decreased.When the number of holes increases from 2 to 3,the maximum fracturing pressure change rate is 16.3%.The feasibility of directional fracturing and rock breaking under the action of holes is verified by experiments.