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通过对伯格斯模型和西原模型的分析比较,选取西原模型研究岩体结构面的蠕变损伤特性。在τ0<τs情况下,由西原模型推出剪切模量的表达式,以剪切模量为变量定义损伤变量,得到结构面的损伤变量表达式。并以泥岩剪切试验为例,计算了相同正压力作用下的结构面剪切模量和损伤量。结果表明:当τ0<τs时,剪切模量、损伤量均随时间趋于稳定,且结构面蠕变的前两个阶段损伤量较小,而当τ0≥τs时,一段时间后,其损伤量开始突变;剪应力越大,其初始剪切模量越大,随时间降低越快,达到稳定蠕变阶段时降低量也相应越大;剪应力越大,结构面损伤量随时间增长越快,在达到稳定蠕变阶段时,损伤量也越大。
By analyzing and comparing the Burgers model and the Nishihara model, the Nishihara model is selected to study the creep damage characteristics of rock mass structural plane. In the case of τ0 <τs, the expression of shear modulus is deduced from Nishihara model, and the damage variable is defined by using shear modulus as a variable to obtain the expression of damage variable of structural plane. Taking the shear test of mudstone as an example, the shear modulus and damage of the structural plane under the same positive pressure are calculated. The results show that when τ0 <τs, the shear modulus and the damage amount tend to be stable with time, and the damage in the first two stages of the structural plane creep is small. When τ0 ≥ τs, after a period of time, The damage amount begins to change suddenly. The larger the shear stress, the bigger the initial shear modulus, the faster the time decreases, and the lower the amount reaches the stable creep phase. The larger the shear stress, the more damage the structural surface increases with time The faster, the more damaging the amount is when the steady creep phase is reached.