针对中高地应力条件下节理岩体地下洞室的爆破开挖引发的节理松动问题,基于应力波理论建立了节理岩体的瞬态卸荷力学模型,证明了简单条件下节理卸荷松动效应的存在.其次,运用离散元数值模拟方法,研究了考虑地应力瞬态调整过程的圆形隧洞节理围岩松动过程.研究表明,地应力瞬态调整过程中,圆形隧洞岩体径向应力的调整过程较直接简单,而切向应力则较为复杂;洞壁附近的节理岩体中可能形成远大于静态塑性区的松动损伤区,使最终屈服区以外的节理面强度和渗透性等力学参数发生劣化;地应力瞬态调整将在节理岩体中诱发质点的振动,是节理面损伤的主要来源.%Loosing mechanism of jointed rock mass caused by transient adjustment of in-situ stress was analyzed. The Mathematical model to simulate the dynamic unloading process of the jointed rock mass was built. With this model, it was found that rock mass joints loose when normal stress unloads transiently. And the loosing process of jointed rock mass in a circular tunnel was analyzed with the distinct element method (UDEC 4.0). It was proposed that the radial stress adjustment process of rock blocks is direct and simple, and that of the tangential stress is more complicated; a loosing zone is formed in a jointed rock mass, it is probably much larger than the static plastic zone; the mechanical parameters of joints in the loosing zones, such as, strength and permeability decrease; transient adjustment of in-situ stress induces particle vibration which is an important damage source of jointed rock mass.
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