层理角度对砂岩力学特性及断裂破坏规律影响研究

Study on the Influence of Bedding Angle on the Mechanical Properties and Fracture Failure Behavior of Sandstone

为探究不同层理角度下砂岩的力学特性以及裂纹扩展规律,对五种层理角度砂岩试样进行抗压强度和抗拉强度测试,并采用半圆盘试样进行Ⅰ型断裂韧度测试,获得其破坏荷载,借助有限元分析软件计算其断裂韧度,研究层理角度对砂岩力学特性的影响。研究表明:层理角度对砂岩抗压强度、弹性模量以及抗拉强度的影响非常显著,且随着层理角度的增加,其断裂韧度呈逐渐减小的趋势。裂纹的扩展路径分析结果表明,层理角度为0°和30°的试件破坏状态受层理面影响较小;当层理角度大于45°时,试样破坏主要受层理角度影响,其破坏路径沿层理角度方向扩展。研究结果为层理角度对砂岩断裂破坏和裂纹扩展路径的影响提供了新的思路。

To investigate the mechanical properties and crack propagation behavior of sandstone under varying bedding angles,compressive strength and tensile strength tests were conducted on sandstone samples with five bedding angles.And semi-circular sandstone specimens were used to test the type I fracture toughness and to obtain its failure load.The fracture toughness was calculated using finite element analysis software,and the influence of bedding angle on the mechanical properties of sandstone was studied.Research results show that the bedding angle has a significant influence on the compressive strength,elastic modulus,and tensile strength of sandstone,and as the bedding angle increases,its fracture toughness gradually decreases.The analysis of crack propagation path shows that the failure states of specimens with bedding angles of 0°and 30°are less affected by bedding planes.When the bedding angle exceeds 45°,the failure of the specimen is mainly affected by the bedding angle,leading to an expansion of the failure path along the bedding angle.The study provides new ideas for the influence of bedding angle on fracture failure and crack propagation path of sandstone.