摘要
为有效解决深井软弱围岩巷道稳定控制技术难题,以淮南某矿-962 m轨道大巷为工程背景,依据软岩应力-应变曲线及围岩应力变化和强度之间的关系,建立圆形巷道围岩破坏分区力学模型,将开挖后的巷道由表及里依次划分为残余区、塑性软化区、塑性硬化区及弹性区,以阐明锚杆(索)锚固系统变形失稳机制,并提出深井软弱围岩的控制要点及关键技术。在此基础上,提出高预应力支护构件遏制残余区扩展、有效的支护承载区发挥围岩承载能力、极大提高软弱围岩承载强度及完整性、薄弱部位补强支护形成完整承载圈等4个围岩控制要点,进而提出“以高强预应力锚杆(索)为核心,浅、深孔分次注浆为基础,底角与底板锚注加固为关键”的全断面强化联合控制方案。结合支护方案特点提出实现内、外承载的“耦合叠加承载拱”结构。该耦合承载拱将支护体与围岩的相互作用和所提供的径向支护力相统一,对锚杆(索)支护阻力具有显著的放大作用。研究结果表明:围岩残余范围随硬化系数、软化系数、支护阻力及内聚力和内摩擦角的增大而减小,随扩容系数的增大而增大,而残余区、塑性软化区、塑性硬化区的边界发生渐进式扩展变换是导致围岩大规模破碎和锚杆(索)锚固失效根本原因。通过工程计算得到轨道大巷围岩屈服软化时的原岩应力阈值可达29.09 MPa,验证了支护方案的可靠性。轨道大巷经联合控制后围岩变形量仅为原支护参数下的12.6%~14.3%,在40 d后变形速率低于0.2 mm/d,实现了对巷道的稳定性控制。
In order to effectively address the stability control technology issues of soft surrounding rock roadways in deep mines,taking the-962 m track roadway of a certain mine in Huainan as the engineering background,a mechanical model for the failure zone of the circular roadway's surrounding rock was established,by examining the relationship between the stress-strain curve of soft rock and the stress change and strength of the surrounding rock.The excavated roadway was subdivided into four zones:residual,plastic softening,plastic hardening,and elastic,progressing from the surface inwards.The deformation and instability mechanisms of the bolt(cable)anchorage system were elucidated,and the control points and key technologies for soft surrounding rock in deep mines were presented.Based on these findings,four key aspects of surrounding rock control were proposed:employing high pre-stressed support components to restrain residual area expansion,optimizing support bearing area to maximize the surrounding rock's bearing capacity,significantly enhancing the bearing strength and integrity of weak surrounding rock,and reinforcing support at vulnerable locations to form a complete bearing ring.Subsequently,a comprehensive strengthening joint control strategy was proposed.This strategy centers around high-strength pre-stressed anchors(cables),with shallow and deep hole grouting as the foundation,and bottom angle and bottom plate bolting and grouting reinforcement as crucial elements.In conjunction with the support scheme's characteristics,a"coupling superimposed bearing arch"structure was introduced to achieve internal and external bearing.The coupling bearing arch integrated the interaction between the support body and the surrounding rock,as well as the radial support force supplied,resulting in a significant amplification effect on the bolt(cable)support resistance.The results show that the residual range of the surrounding rock diminishes with increasing hardening coefficient,softening coefficient,support resistance,cohesion,and internal friction angle,while it expands with an increasing expansion coefficient.The progressive enlargement and transformation of the boundary between the residual zone,plastic softening zone,and plastic hardening zone are the primary causes of large-scale crushing of the surrounding rock and bolt(cable)anchorage failure.Lastly,engineering calculations demonstrate that the original rock stress threshold reaches 29.09 MPa when the track roadway's surrounding rock yields and softens,verifying the reliability of the support scheme.Simultaneously,field monitoring data reveal that the deformation of the surrounding rock,after the combined control of the track roadway,is only 12.6%to 14.3%of the original support parameters.The proposed approach substantially improves the stability of the soft surrounding rock roadway in deep mines.
作者
王想君
李英明
赵光明
刘刚
程详
朱世奎
WANG Xiangjun;LI Yingming;ZHAO Guangming;LIU Gang;CHENG Xiang;ZHU Shikui(State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China;Key Laboratory of Safe and Effective Coal Mining,Ministry of Education,Anhui University of Science and Technology,Huainan 232001,China;Post-Doctoral Research Station,Huaibei Mining Corporation Limited,Huaibei 235000,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第6期2496-2512,共17页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52174102,51974009,52004005,52204082)
安徽省重点研究与开发计划项目(2022m07020007)
安徽省科技重大专项(202203a07020011)
安徽省高校协同创新项目(GXXT-2021-075)
安徽省“特支计划”领军人才项目(T000508)
安徽省博士后基金项目(2021B513)。
关键词
深井软弱围岩巷道
围岩破坏分区
联合支护
耦合叠加拱承载
deep soft rock roadway
surrounding rock failure zoning
combined support
bearing capacity of coupled superimposed arch
