裂隙倾角对泥质白云岩强度影响试验研究

地下岩体中普遍存在的裂隙是影响岩体拉压性能的重要因素之一。依托贵阳轨道交通工程,采集泥质白云岩,开展劈裂试验和单轴压缩试验,分析了不同裂隙角度对泥质白云岩拉、压性能的影响。结果表明:(1)劈裂试验中,泥质白云岩抗拉强度为3～7 MPa,平均值为5. 03 MPa,抗拉强度随裂隙角度的增大呈下降趋势,劈裂模量为0. 1～2. 84 GPa,整体呈幂函数下降趋势;(2)泥质白云岩的抗压强度较高,分布在60～130 MPa之间,平均抗压强度为87. 25 MPa;随裂隙角度的增大,试样抗压强度呈先减小后增大趋势;通过理论推导,得出岩体中最易破裂裂隙角度为22. 5°～45°,与试验结果相符;弹性模量随裂隙倾角整体呈上升趋势;(3)通过对泥质白云岩拉压强度对比,得出泥质白云岩抗压强度平均值与抗拉强度平均值之比为18. 97。

Experimental study on influence of fissure dip angle on strength of argillaceous dolomite

Generally exists in underground rock mass fracture is one of the important factors that affect tension and compression properties of rock mass. Relying on the guiyang railway traffic engineering, to collect argillaceous dolomite for splitting and uniaxial compression test specimens,analysis of the different fracture angle effect on the properties of argillaceous dolomite and compressive.The results showed that: 1)Splitting test of argillaceous dolomite tensile strength concentrated in 3~7 MPa range, with a mean of 5.03 MPa, the whole into a downward trend with the increase of fracture angle, splitting modulus is concentrated in 0.1~2.84GPa, the overall decline in power function;2)By uniaxial compression test of argillaceous dolomite of high compressive strength, distribution between 60~130MPa, the average compressive strength of 87.25 MPa.With the increase of fracture angle, compressive strength of the sample generally presents a trend of increase with the decrease of the first.Through theoretical derivation, it is concluded that the most easily broken rock mass fissure Angle is 22.5°to 45°,consistent with experimental results.The modulus of elasticity with the crack angle integral into a rising trend;3)By means of argillaceous dolomite and compressive strength contrast, argillaceous dolomite average compressive strength and tensile strength ratio of the average of 18.97.