摘要
针对强动压巷道顶板离层问题,基于弹塑性及断裂力学原理,从理论角度分析了强动压巷道顶板离层全程演化机制,建立了两端固支岩梁力学模型,系统分析了反映离层机制的5大类表征量,对比论述了高静载及强动压2种应力条件下的离层演化机制,探讨了层间离层与岩梁不同破裂形态的共生关系。研究表明:强动压巷道在高地应力和强动压作用下,顶板岩梁由弹性状态向塑性或破裂性态进行不可逆的渐进演变或突变失稳,层间离层持续萌生扩展并与岩层自身累积的损伤裂缝交合贯通,顶板被迫进入“离层-破裂”“破裂-离层”及“离层-震荡-震裂”的恶性循环,产生极大的安全隐患;强动压巷道顶板岩梁结构必须保持较好的完整性、较大的厚跨比及较大的强度,形成“厚-硬-小”的强力承载结构,使顶板岩梁尽量保持弹性、控制塑性、防止破裂,确保顶板结构稳定及离层可控。
Based on the principle of elastic-plasticity and fracture mechanics,we analyzed the evolution mechanism of roof separation in the roadways with strong dynamic pressure,established a mechanical model of a rock beam with fixed supports at both ends,and analyzed five indicators reflecting the separation mechanism.The study compares the separation evolution mechanisms under high static load and strong dynamic pressure,exploring the symbiotic relationship between interlayer separation and various fracture patterns of the rock beam.Results show that under high geostress and strong dynamic pressure,the roof rock beam undergoes irreversible gradual evolution or catastrophe instability from an elastic state to a plastic or fractured state.The interlayer separation continuously initiates and expands,merging with accumulated damage cracks within the rock layer,which forces the roof into a vicious cycle of“separation-fracture,”“fracture-separation,”and“separation-oscillation-shock fracture,”posing significant safety risks.The roof rock beam structure in roadways under strong dynamic pressure must maintain good integrity,large thickness-span ratio,and high strength.Forming a"thick-hard-small"strong load-bearing structure allows the roof rock beam to remain elasticity,control plasticity,and prevent fracturing,ensuring roof structure stability and controllable separation.
作者
刘亚明
LIU Yaming(Jinhuagong Mine,Jinneng Holding Coal Industry Group,Datong 037016,China)
出处
《山西煤炭》
2024年第3期115-122,共8页
Shanxi Coal
关键词
顶板离层
高地应力
离层表征量
顶板破裂演化机制
顶板岩梁结构
roof separation
high geostress
separation indicators
roof cracking evolution mechanism
rock beam structure
