9 / 2025-11-14 15:36:11

周期应力扰动下岩石蠕变宏-微观损伤规律研究（Macro-micro response characteristics of sandstone creep under the influence of periodic stress disturbance）

应力扰动，蠕变，损伤

本研究针对砂岩在高频扰动作用下的蠕变特性进行了系统分析，并采用核磁共振（NMR）技术研究砂岩在扰动蠕变前后的孔隙结构变化。通过横向弛豫时间（T₂）谱分布、孔隙度变化以及大孔（T₂>10 ms）与微孔（T₂<10 ms）比例变化等参数，对其演化特征进行了定量分析。同时，研究了扰动前后蠕变应变的变化规律，以及每次扰动后稳定应变的变化特性。试验结果表明：（1）蠕变作用与应力扰动均会促进砂岩孔隙度的增加，且加载比越大，应力扰动对孔隙度变化的影响越显著；（2）在扰动蠕变过程中，大孔比例的变化趋势与孔隙度变化一致；（3）扰动前后应变增量的变化趋势与孔隙度变化规律相似，扰动频率越高，应变增量越小，稳定蠕变阶段的应变速率也越低；（4）蠕变应变与孔隙度增量之间呈正相关关系。本研究成果可为高强度采动条件下围岩稳定性分析和矿山安全防护提供理论支撑。



This work studied the creep characteristics of sandstone under high-frequency disturbance. The Nuclear magnetic resonance (NMR) technology was used to investigate the characteristics of pore changes in sandstone before and after disturbance creep. Quantitative analysis was conducted on the transverse relaxation time (T₂) distribution, changes in porosity, and percentage changes in macropores (T₂ > 10 ms) and micropores (T₂ < 10 ms). Moreover, the variation characteristics of creep strain before and after disturbance creep, as well as the corresponding changes in steady-state creep strain and creep strain rate after each disturbance, were also studied. The experimental results first showed that the creep behavior and stress disturbance both promoted the increase of sandstone porosity. The larger the loading ratio, the more significant the impact of stress disturbance on porosity changes. Second, during the disturbance creep process, the percentage change of macropores was consistent with the change of porosity. Third, the steady-state creep strain and creep strain rate after each disturbance increase with the increase of loading ratio, while the steady-state creep strain and creep strain rate after each disturbance decrease with the increase of disturbance frequency. Final, a positive correlation between creep strain and porosity increment was found. The study can provide theoretical support for the stability analysis of surrounding rock and mine safety protection under high-intensity mining.