深部软岩巷道围岩变形稳定性评价及合理支护参数选择  

Evaluation of Surrounding Rock Deformation Stability in Deep Soft Rock Roadway and Selection of Support Parameters

作　　者：吴德义 范坤 WU Deyi;FAN Kun(School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China;National and Local Joint Engineering Laboratory of Building Health Testing and Disaster Prevention Technology,Hefei 230601,China)

机构地区：[1]安徽建筑大学土木工程学院,安徽合肥230601 [2]建筑健康检测与灾害预防技术国家地方联合工程实验室,安徽合肥230601

出　　处：《厦门理工学院学报》2025年第1期77-84,共8页Journal of Xiamen University of Technology

基　　金：国家自然科学基金“深部煤岩稳定性量化判别研究”(51374009);国家自然科学基金“深部煤巷帮部预应力锚索压缩拱合理承载机制及计算理论研究”(51674005)。

摘　　要：为保障深部软岩巷道围岩的安全、稳定,基于典型工程实例,以巷道开挖后围岩表面变形呈现二次蠕变快慢和二次蠕变速度衰减系数为评价指标,开展深部软岩巷道围岩变形稳定性评价及合理支护参数选择。研究表明:巷道围岩表面变形的一次蠕变作用时间为15~30 d,其二次蠕变系数与一次蠕变作用时间和围岩变形稳定性密切相关。极稳定状态围岩仅产生一次蠕变;稳定状态、基本稳定状态及不稳定状态下围岩的二次衰减系数分别为≥0.05、0.04~0.05、<0.04,极不稳定状态巷道开挖后仅在5~15 d内围岩变形即进入加速变形阶段;处于破坏碎胀变形阶段围岩的二次蠕变时点为≤30 d;需在一次蠕变结束后立即进行二次支护(二次支护时间T=20~25 d)。锚杆(索)支护选择应依据松动圈厚度R确定,R>2.5 m部位,锚索长度取L=R+(0.5~1.0 m);R<2.5 m部位,锚杆长度取L=R+(0.3~0.5 m)。To ensure the safety and stability of deep soft rock roadway surrounding rock,the evaluation of the deformation stability of deep soft rock roadway surrounding rock and the selection of reasonable support parameters were carried out based on typical engineering examples,taking as the evaluation indicators the speed of secondary creep and the attenuation coefficient of secondary creep speed of the surrounding rock surface deformation after roadway excavation.The research shows that the time of primary creep of the surrounding rock surface deformation is 15 to 30 days,and the secondary creep coefficient is closely related to the time of primary creep and the stability of surrounding rock deformation.The surrounding rock in the extremely stable state undergoes only primary creep,while the secondary attenuation coefficients of the surrounding rock in the stable state,basically stable state and unstable state are≥0.05,0.04 to 0.05 and<0.04 respectively.In the extremely unstable state,the surrounding rock deformation enters the accelerated deformation stage within 5 to 15 days after the roadway excavation.The secondary creep time point of the surrounding rock in the destruction and expansion deformation stage is≤30 days,and secondary support is required immediately after the end of primary creep(the secondary support time T=20 to 25 days).The selection of anchor bolt(cable)support should be based on the thickness of the loosening zone R.For parts with R>2.5 m,the length of the anchor cable is L=R+(0.5 to 1.0 m),and for parts with R<2.5 m,the length of the prestressed anchor bolt is L=R+(0.3 to 0.5 m).

关 键 词：深部软岩巷道 围岩蠕变 围岩失稳 巷道表面变形 支护参数 二次支护 松动圈 

分 类 号：TD322[矿业工程—矿井建设]