强冲击载荷下巷道围岩变形破坏特征及控制技术

Characteristics of deformation and failure of surrounding rock in roadway under strong impact load and control technology

针对冲击地压巷道围岩及支护结构变形破坏难题,采用数值计算、现场实测、现场试验等研究方法,分析了强冲击载荷下巷道围岩及支护结构变形破坏特征,研究了冲击载荷、采动应力等对巷道围岩和支护结构动态力学响应的影响,开发了抗冲击支护材料,提出了支护-卸压联合控制技术,并选择典型冲击地压矿井进行了应用。研究结果表明:巷道顶板发生冲击时,巷道顶板、两帮和底板质点最大振速分别为1.41、0.63、0.25 m/s,迎波侧巷表围岩受冲击影响最大,侧向次之,背波侧最小。在采动应力与冲击载荷叠加作用下巷道破坏范围更大,塑性区面积达到原岩应力时的2.1倍。随着冲击能量的增加,巷道变形量和质点振动速度峰值均急剧增大,且锚杆(索)受力也出现明显波动。爆破卸压对巷帮锚杆锚固力影响不大,而对锚索锚固力有明显影响,锚索锚固力平均降低26.7%。高冲击韧性锚杆屈服强度800 MPa,断后伸长率20%,冲击吸收功150 J;高延伸率锚索最大力延伸率8%,抗拉强度1770 MPa。联合控制技术在宽沟煤矿进行了现场应用,巷帮锚杆受力53~84 kN,顶板锚索受力122~219 kN,锚杆(索)受力均处于安全允许范围之内,顶板浅部和深部未发生离层,在大能量微震事件作用下,支护系统也能保持稳定。

In response to the challenging problem of deformation and failure of surrounding rock and support structures in roadways under rock burst,a comprehensive research approach involving numerical calculations,field measurements,and laboratory experiments was employed.The study analyzed the characteristics of deformation and failure of surrounding rock and support structures in roadways under strong impact load,investigated the influence of impact load and mining-induced stress on the dynamic mechanical response of surrounding rock and support structures,developed impact-resistant support materials,and proposed a support-unloading coordination control technology,and selected typical rockburst mines for application.The research findings indicate that when the roadway roof is impacted,the maximum particle velocities of the roof,sidewalls,and floor are 1.41 m/s,0.63 m/s,and 0.25 m/s,respectively.The surrounding rock on the advancing side of the roadway is most affected by the impact,followed by the lateral side,with the retreating side being the least affected.The combined effect of mining-induced stress and impact load results in a larger range of roadway damage,with the plastic zone area reaching 2.1 times the original rock stress.With increasing impact energy,the deformation and peak particle vibration velocities of the roadway increase sharply,and there is noticeable fluctuation in the force on the bolts(cables).Blast destressing has little effect on the anchoring force of the roadway sidewall bolts but significantly affects the anchoring force of the anchor cables,with an average reduction of26.7%in anchoring force of the anchor cables.The yield strength of high impact toughness anchor rod is 800 MPa,the elongation at break is 20%,and the impact absorption energy is 150 J;The maximum force extension rate of the high elongation anchor cable is 8%,and the tensile strength is 1770 MPa.The coordination control technology was field-tested in a Kuangou coal mine,where the forces on the sidewall bolts ranged from 53 to 84 kN,and the forces on the roof anchor cables ranged from 122 to 219 kN,all within the safe allowable range.The shallow and deep separation layers of the roof have not occurred,and even in the event of a large energy microseismic event,the support system remained stable.