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为揭示冻融循环作用对板岩弹性参数及单轴抗压强度的影响,采用DX-40型低温数控箱、DNS100微型控制电子万能试验机进行7种层理倾角(?)、6种冻融循环次数的单轴压缩试验,对其5个弹性参数、单轴抗压强度及破坏类型的变化规律进行分析。试验结果表明:板岩弹性模量、剪切模量和单轴抗压强度随冻融循环次数增加呈指数下降趋势,泊松比随冻融循环次数增加呈线性增加趋势;板岩单轴抗压强度随层理倾角增加呈先减后增的变化趋势;冻融循环作用下板岩破坏类型有3种:当0°≤?≤26.6°时,沿与竖直轴线呈一定角度方向发生剪切破坏;当26.6°≤?≤83.0°时,沿层理面发生剪切破坏;当83.0°≤?≤90°时,沿垂直方向发生劈裂破坏。在Jaeger单弱面理论的基础上,建立了以冻融循环次数和层理倾角为控制变量的板岩单轴抗压强度预测模型,并通过试验数据验证了模型的合理性,表明该模型能较好地描述冻融循环次数和层理倾角对冻融板岩单轴抗压强度的影响。
In order to reveal the influence of freeze-thaw cycles on slate elastic parameters and uniaxial compressive strength, seven kinds of bedding inclination (?) And six kinds of freezing and thawing (?) Were carried out by DX-40 low temperature numerical control box and DNS100 micro-control electronic universal testing machine Uniaxial compression tests of the number of cycles, the variation of five elastic parameters, uniaxial compressive strength and failure types were analyzed. The experimental results show that the elastic modulus, the shear modulus and the uniaxial compressive strength of the slate decline exponentially with the increase of the number of freeze-thaw cycles, and the Poisson’s ratio increases linearly with the increase of the number of freeze-thaw cycles. The compressive strength decreases with the increase of bedding inclination and then increases. The type of slate failure under freeze-thaw cycling is three types: when 0 ° ≤? ≤26.6 °, shearing occurs along an angle with the vertical axis When the angle is 26.6 ° ≤Δ83.0 °, shear failure occurs along the bedding plane. When 83.0 ° ≤≤90 °, splitting failure occurs in the vertical direction. Based on the Jaeger theory of single weak surface, the prediction model of uniaxial compressive strength of slate with the numbers of freeze-thaw cycles and bedding inclination as control variables is established. The experimental data verify the rationality of the model, The effects of freeze-thaw cycles and bedding inclination on the uniaxial compressive strength of frozen-thawed slate are well described.