摘要
针对传统周边爆破易诱发随机裂纹损伤围岩问题,结合弹性力学理论与基于ANSYS/LS-DYNA的数值模拟方法,对空孔定向爆破中的损伤演化规律与动力响应特性进行了深入分析。首先,基于弹性力学理论,阐释了空孔在爆炸荷载下通过应力波反射产生拉应力集中从而实现对定向裂纹扩展的控制机制;接着,通过建立平面双孔不耦合装药数值模型,系统研究了炮孔间距和地应力场对损伤演化的影响;最后,分析了空孔附近峰值应力和质点峰值振速的动态变化规律。结果表明:空孔能够显著改变爆炸能量分布,将其引导至集中于炮孔连线方向,从而有效抑制非预期裂纹的萌生和扩展;空孔的定向效果受地应力场的调控,高地应力条件会削弱空孔水平方向的拉应力集中程度,进而抑制炮孔间裂纹扩展,故炮孔宜平行于岩体最大主应力方向布置,使定向效果最大化,并减弱地应力的抑制作用;当炮孔间距为11~14倍炮孔直径时,可促进主裂纹的稳定定向扩展,抑制非预期裂纹的发育,显著改善围岩损伤的控制效果。在高地应力工况下,建议将炮孔间距参考值适当缩小至8~11倍炮孔直径。
Aiming at the issue that traditional perimeter blasting easily induces random crack damage in surrounding rocks,this study conducts an in-depth analysis of the damage evolution laws and dynamic response characteristics in empty-hole directional blasting by integrating elastic mechanics theory with numerical simulation methods based on ANSYS/LS-DYNA.Firstly,drawing on the theory of elastic mechanics,the mechanical mechanism was elucidated whereby empty holes generate tensile stress concentration through stress wave reflection under explosive loading,thereby controlling the propagation of directional cracks.Subsequently,by establishing a numerical model of planar double-hole decoupled charge blasting,the effects of blasthole spacing and in-situ stress field on damage evolution were systematically investigated.Finally,the dynamic variation patterns of peak stress and peak particle vibration velocity near the empty hole were analyzed.The results indicate that empty holes can significantly alter the distribution of explosion energy,guiding it to concentrate along the line connecting the blastholes,thereby effectively suppressing the initiation and propagation of unintended cracks.The directional effect of empty holes is modulated by the in-situ stress field;high in-situ stress conditions reduce the degree of tensile stress concentration in the horizontal direction of the empty hole,thus inhibiting crack propagation between blastholes.Therefore,blastholes should be arranged parallel to the maximum principal stress direction of the rock mass to maximize the directional effect and mitigate the inhibitory influence of in-situ stress.When the blasthole spacing is 11-14 times the blasthole diameter,stable directional propagation of main cracks is promoted,the development of unintended cracks is suppressed,and the control of surrounding rock damage is significantly improved.Under high in-situ stress conditions,it is recommended to appropriately reduce the reference hole spacing to 8-11 times the blasthole diameter.
作者
李涛
倪羽
王志亮
LI Tao;NI Yu;WANG Zhiliang(School of Civil Engineering,Hefei University of Technology,Hefei 230009,Anhui,China)
出处
《高压物理学报》
北大核心
2026年第2期59-72,共14页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(12272119,U1965101)。
关键词
岩石
空孔效应
损伤演化
动力响应
地应力
裂纹
rock
empty hole effect
damage evolution
dynamic response
geostress
crack
