锚网喷注联合支护技术在硐室修复加固中的应用

Application of bolt and grouting combined support in chamber repair and reinforcement

随着国家对矿产资源的开采逐渐向深地延伸,如何控制硐室大变形,确保支护结构的有效性成为深部软岩硐室支护的首要问题。本文以广西某复杂地质条件地下锰矿大断面硐室为工程背景,基于现场监测硐室大变形破坏及支护失效,运用FLAC3D精细化模拟了硐室围岩破坏变形的演化规律,讨论了地层侧压力、岩体软化系数、不同支护形式3个因素对硐室围岩变形、塑性区范围等的影响规律,基于此,论证了锚网喷支护对深部硐室支护具有明显的局限性,而锚网喷+锚注联合迭加支护技术是一种行之有效的围岩控制方式。监测结果表明:采用锚网喷+锚注联合迭加支护技术能够有效地控制深部硐室大变形,能保持硐室的长期稳定与安全。

With the mining of mineral resources gradually extending to deep ground,how to control the large deformation of the chamber and ensure the effectiveness of the supporting structure has become the primary problem of chamber supporting of deep soft rock.Taking a large-section chamber of underground manganese ore under complex geological condition in Guangxi as engineering background,based on the field monitoring results of large deformation occurred in the chamber and the supporting structure also failed,the law of surrounding rock failure and deformation is simulated by FLAC3D,the influence of formation lateral pressure,rock softening coefficient and different support forms on the deformation of surrounding rock of the chamber and plastic zone range is discussed.Based on that,it is proved that the anchor net spray supporting has clear limitations on deep chamber supporting,but anchor net spray+anchor-grouting combined support technology is an effective method for surrounding rock controlling.The monitoring results show that anchor net spray+anchor-grouting combined support technology can effectively control deep chamber deformation,and can maintain the long-term stability and safety of the chamber.