基于长期强度的节理岩体洞室蠕变特性研究

摘要

In order to reveal the creep properties of tunnel opening in joint rock mass, the Rock Failure Process Analysis System is used by the introduction of long-term strength of rock and the elastic-brittle consid-ered constitutive for meso-unit, which is different from the traditional methods of elastic-plastic or viscoelastic plastic constitutive to analyze the rheological properties of jointed rock on the view of macroscopic. The numer-ical simulations of jointed rock cavern under different conditions are investigated, and the effects of joint inter-val and joint angle on the creep and failure characteristics are analyzed. The calculation results show that the uniaxial creep deformation for rock mass decreases with the increase of joint interval and it increases with the increase of dip angle of joint plane if the angle is smaller than 45 ° , while the result will be quite on the contra-ry if the angle is larger than 45 ° . If the angle is 45 ° , a large number of failures in surrounding rock emerge and the characteristic accelerating creep stages are exhibited.%为了进一步探究节理岩体蠕变特性，摆脱传统意义上从宏观弹塑或粘弹塑本构的角度分析岩体流变特性的方法，将细观单元视为弹脆性的本构关系，采用考虑岩石长期强度的岩石破裂过程分析系统，通过对不同工况下的节理岩体洞室数值模拟，得到了节理间距和节理夹角对围岩蠕变特性及其破坏特征的影响规律。结果表明：节理岩体洞室围岩的蠕变量随着节理面间距的增大而减小；当节理面的水平夹角小于45°时，节理岩体洞室围岩蠕变量随着节理面夹角的增大而增大，但当节理面倾角大于45°时，蠕变量反而随着节理面倾角的增大而减小，当节理面倾角等于45°时，围岩出现大量破坏，并表现出加速蠕变的特征。