不同加载速率下X型节理间相互干涉对岩体力学特性影响

Influence of Mutual Interference between X-shaped Joints on Mechanical Properties of Rock Mass under Different Loading Rates

X型节理岩体广泛分布于自然界,准确认识不同加载速率下X型节理岩体破裂失效机制对相关岩体工程的科学评价至关重要。文中通过制作X型节理岩体相似材料试件,改变主次相交节理的几何特征及加载速率,采用DIC技术实时监测主次节理尖端扩展,研究X型节理间相互干涉对岩体力学特性的影响规律。结果表明,不同加载速率下X型节理间的干涉效应对弹性变形阶段及屈服阶段的力学特性具有显著影响。对于含45°主节理的同倾向X型节理岩体,随着次节理倾角的增大,岩体起裂强度先减小后增大;而对于反倾向X型节理岩体,随着次节理倾角的增大,岩体起裂强度先增大后减小,且β=120°时干涉效应最强,其加载速率效应也先增大后减小。

X-type jointed rock mass is widely distributed in nature.It is very important to accurately understand the failure mechanism of X-type jointed rock mass under different loading rates for the scientific evaluation of related rock mass engineering.By making X-joint rock mass similar material specimens,changing the geometric characteristics and loading rate of primary and secondary intersecting joints,using DIC technology and ultrasonic real-time monitoring of primary and secondary joint tip extension,the influence of mutual interference between X-joints on the mechanical properties of rock mass is studied.The results show that the interference effect between X-joints under different loading rates has a significant impact on the mechanical properties of elastic deformation stage and yield stage.For the same dip X-type jointed rock mass with 45°main joints,with the increase of secondary joint dip angle,the initial crack strength of rock mass first decreases and then increases,while for the anti dip X-type jointed rock mass,with the increase of secondary joint dip angle,the initial crack strength of rock mass first increases and then decreases,andβ=The interference effect is the strongest at 120°,and the loading rate effect also increases first and then decreases.