不同倾角节理岩体损伤演化特征分析

为研究节理倾角对岩体损伤的影响规律,运用损伤力学理论建立考虑节理与荷载共同作用的岩体损伤演化模型及损伤本构模型;通过单弱面理论对模型试验进行验证,同时探讨节理岩体损伤演化特征.结果表明:单弱面理论结果与试验结果较为吻合,模型试验能较好地表征含单一结构面的岩体在荷载作用下的力学特征及损伤演化规律;当节理倾角从0增大到90°过程中,初始节理损伤先增后减,在倾角为60°时至最大值,总体呈倒"U"型分布规律;不同倾角节理岩体总损伤演化规律基本一致,均呈"S"型分布规律,先缓慢增加,而后快速增加,最后再缓慢增加其值趋于1;节理倾角只影响总损伤率数值大小不影响其演化规律,总损伤率随应变增加呈正态分布;总损伤率受控于节理面分布规律,当节理倾角从0增大至90°的过程中,总损伤率先减小后增大.

Analysis of damage evolution characteristics of jointed rock mass with different joint dip angles

To study the influence of joint dip angle on rock mass damage, the damage evolution model and damage constitutive model of jointed rock mass were built considering the combined action of joint and load based on damage mechanics theory. The model test was verified by the single weak surface theory, and the damage evolution characteristics of the jointed rock mass were investigated. Results showed that the theoretical results of single weak surface theory were in good agreement with the experimental results. The model test could better characterize the mechanical characteristics and damage evolution law of the rock mass with single structural plane under load. The initial jointed damage showed an inverted U-type distribution that it increased first and then decreased with the increase of the joint dip angle, and it reached the maximum value when the dip angle was 60°. The total damage curve showed an S-type distribution that it grew slowly first, then rapidly, and finally slowly approached 1. The joint dip angle only affected the magnitude of the total damage rate instead of its evolution trend. The total damage rate curve showed a normal distribution that it increased first and then decreased with the increase of the strain. The total damage rate was affected by the distribution of the joint plane, which decreased first and then increased when the joint dip angle increased from 0° to 90°.