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为探讨在采动应力反复扰动下煤的变形及渗透特性,利用自主研发的含瓦斯煤岩热流固耦合三轴伺服渗流装置,进行不同稳定时间条件下煤的循环荷载试验。研究结果表明:(1)不同稳定时间条件下煤的循环加卸载应力–应变曲线不相重合,形成塑性滞回环;随着稳定时间的增加,渗透率有相同的变化趋势,初始渗透率下降幅度亦减小。渗透率与轴向应变随主应力差增加呈负相关变化,轴向应变增大渗透率减小,反之亦然。(2)煤的轴向应变最大值随稳定时间增加先减小后增大,并在稳定时间为100 s时到达最小;渗透率最小值随稳定时间增加先增大后减小,并在稳定时间为100 s时到达最大。煤的渗透率变化与轴向变形的发展密切相关。(3)不同稳定时间条件下煤的渗透率变化均滞后于体积应变变化,且随稳定时间的增加,滞后量有增大的趋势。
In order to discuss the deformation and infiltration characteristics of coal under the repeated disturbance of mining stress, the cyclic load test of coal under different steady time conditions was carried out by using self-developed thermal-solid-fluid coupling three-axis servo seepage device. The results show that: (1) The cyclic loading-unloading stress-strain curves of coal under different stabilization time do not coincide to form plastic hysteresis loop; with the increase of stabilization time, the permeability has the same trend of change, and the initial permeability decrease Also reduce. Permeability and axial strain are negatively correlated with the increase of the principal stress, while the permeability with increasing axial strain is decreased, and vice versa. (2) The maximum axial strain of coal decreases first and then increases with increasing stabilization time, and reaches its minimum when the stabilization time is 100 s. The minimum value of permeability increases first and then decreases with increasing stabilization time, The maximum time is 100 s. The change of coal permeability is closely related to the development of axial deformation. (3) The change of coal permeability lags behind the change of volumetric strain under different stabilization time conditions, and with the increase of stabilization time, the hysteresis tends to increase.