隐伏非贯通软弱夹层岩质边坡剪切蠕变特征及稳定性研究

Shear creep characteristics and stability of rock slopes with concealed noninterpenetrated weak interlayer

针对隐伏非贯通软弱夹层岩质边坡滑移机理复杂这一关键科学问题。设计一种隐伏非贯通软弱夹层缩尺制备方法,开展考虑夹层埋深、岩层倾角、含水率因素影响下岩体剪切蠕变特性试验。引入多参数岩体渐变损伤变量,分阶段建立剪切蠕变损伤本构模型,并通过相似模拟试验验证模型的合理性,分析此类边坡的稳定性。研究表明:(1)隐伏非贯通含软弱夹层岩体随夹层埋深增加、倾角减小、含水率减小而稳定性升高,反之稳定性降低,且夹层含水率对岩体稳定性影响最大,埋深影响相对较小;(2)考虑多参数渐变损伤本构模型能够反映隐伏非贯通软弱夹层岩体剪切蠕变全过程,且加速蠕变阶段拟合效果优于西原模型;(3)隐伏非贯通软弱夹层缩尺制备方法较为合理,所推剪切蠕变本构模型能够较好拟合边坡蠕变滑移各阶段情况,边坡滑移呈坡脚剪胀、后缘拉裂的整体性滑移,对隐伏非贯通含软弱夹层岩体蠕变滑移具有参考意义。

This study aims to address the key scientific problem of the complex slip mechanism of rock slopes with concealed noninterpenetrated weak interlayer.A scaled preparation method for a concealed noninterpenetrated weak interlayer is designed,and the shear creep characteristics of a rock mass under the influences of the burial depth of interlayer,dip angle of rock and water content are tested.The variable of gradual damage of the multiparameter rock mass is introduced,and the constitutive model for shear creep damage is established in stages.The rationality of the model is verified through the similar simulation experiments,and the stability of this kind of slope is analyzed.The research shows that:(1)The stability of the rock mass with a concealed noninterpenetrated weak interlayer increases as the burial depth of the interlayer increases,the dip angle and water content decrease,the stability otherwise decreases,the water content of the interlayer has the greatest influences on the stability of the rock mass,and the burial depth has a relatively small influence.(2)Considering that the multiparameter gradual damage constitutive model can reflect the whole process of the shear creep of rock masses with concealed nonpenetrated weak interlayer,the fitting effects of the accelerated creep stage are better than those of the Nishihara model.(3)The scaled preparation method for the concealed noninterpenetrated weak interlayers is more reasonable.The constitutive model for shear creep can better fit the creep slip of the slope at each stage.The slope slip shows the overall slip of the shear expansion of the slope toe and trailing edge tension,which has reference significance for the creep slip of concealed noninterpenetrated rock masses with weak interlayers.