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在进行多组不同配比类岩石材料单轴压缩试验和巴西试验的基础上,详细分析了石膏水泥比和石英砂含量对类岩石材料的单轴抗压强度、抗拉强度及弹性模量等力学参数的影响规律,力图找到适合模拟现场砂质泥岩的类岩石材料及配合比。利用颗粒流程序(PFC)模拟,进一步研究了高径比和围压对类岩石材料力学特性的影响。结果表明:随着石膏水泥比的增大,抗压强度和弹性模量均逐渐减小,而抗拉强度逐渐增大;随着石英粉含量的增大,抗压强度和弹性模量均先增大后减小,而抗拉强度则为先减小后增大。结合单轴压缩过程的声发射特征,揭示了裂纹扩展与声发射有密切的关系。PFC2D模拟获得的力学参数与室内试验相近,破裂模式也与实际情况相似。通过尺寸效应的研究可知试样的高径比在2.0~2.5较合理。随着围压的增大,试样的峰值强度、残余强度、峰值应变及弹性模量等力学参数均增大,且围压会改变试样的破裂模式。
Based on the uniaxial compression tests of several groups of rock materials with different proportions and the Brazilian tests, the uniaxial compressive strength, tensile strength and modulus of elasticity of the rock-like materials were analyzed in detail in terms of gypsum cement ratio and quartz sand content Mechanical parameters of the law of influence, trying to find suitable for simulating the site of sandy rock-like rock materials and mix ratio. The effect of height-diameter ratio and confining pressure on the mechanical properties of rock-like materials was further studied by the particle flow program (PFC) simulation. The results show that with the increase of gypsum cement ratio, the compressive strength and elastic modulus decrease gradually, while the tensile strength increases gradually. With the increase of quartz powder content, both the compressive strength and elastic modulus Increase and then decrease, while the tensile strength is reduced first and then increased. Combined with the acoustic emission characteristics of uniaxial compression process, it is revealed that there is a close relationship between crack propagation and acoustic emission. The mechanical parameters obtained by PFC2D simulation are close to those of laboratory tests. The rupture mode is also similar to the actual situation. Through the size effect of the study shows that the sample height to diameter ratio of 2.0 to 2.5 is more reasonable. As the confining pressure increases, the mechanical parameters such as peak strength, residual strength, peak strain and elastic modulus increase, and the confining pressure will change the rupture mode of the specimen.