考虑渗流和剪胀特性的Z-P准则及巷道稳定性分析

Z-P Criterion for Considering Seepage and Shear Expansion Properties and Analysis of Roadway Stability

在地下工程结构中,渗流和剪胀特性严重影响了巷道的稳定性。为了研究渗流和剪胀特性下巷道围岩的稳定性,基于Zienkiewicz-Pande准则和弹塑性理论,分析了受渗透水压力作用下的巷道围岩弹塑性解;推导了渗透水压力作用下的巷道围岩塑性区半径、位移和应力分布的解析解;分析了中间主应力和剪胀角对巷道围岩塑性区的影响规律。结果表明:基于Z-P准则的塑性区半径、位移和围岩应力公式能够很好地反应规律;随着中间主应力的增大,塑性区半径、位移和弹性区应力先减小后增大,塑性区应力先增大后减小;渗流作用下的塑性区半径和位移显著增加;围岩的剪胀特性对巷道应力分布和塑性区半径影响较小,但对位移分布有显著影响,随着剪胀角的增加,塑性区位移逐渐提高。

In underground engineering structure,the seepage and dilatancy characteristics seriously affect the stability of roadway.In order to study the stability of roadway surrounding rock under seepage and dilatancy characteristics,based on Zienkiewicz-Pande criterion and elastoplastic theory,the elastoplastic solution of roadway surrounding rock under osmotic water pressure is analyzed.The analytical solutions of the radius,displacement and stress distribution of the plastic zone in the surrounding rock of roadway under osmotic water pressure are derived.The influence law of intermediate principal stress and dilatancy Angle on the plastic zone of roadway surrounding rock is analyzed.The results show that the formulas of radius of plastic zone,displacement and surrounding rock stress based on Z-P criterion can reflect the law well.With the increase of the intermediate principal stress,the radius,displacement and elastic stress of the plastic zone first decrease and then increase,while the plastic zone stress first increases and then decreases.The radius and displacement of plastic zone increase significantly under seepage.The dilatancy characteristics of surrounding rock have little influence on the stress distribution and plastic zone radius of roadway,but have significant influence on the displacement distribution.With the increase of dilatancy Angle,the plastic location shift gradually increases.