考虑软弱夹层蠕变特性的某矿山边坡稳定性研究

为研究软弱夹层的存在状态对岩土体强度变形特性的影响，选用PFC3D离散元软件进行不同条件下的复合岩样标准三轴试验模拟，深入分析其强度变化规律及变形破坏特征；借助FLAC3D软件建立了依托实际工程的三维模型，选用考虑蠕变特性的Burgers模型，对露天矿山边坡的稳定状态进行深入分析，得到如下结论:（1）软弱夹层的倾角、厚度、层数等参数均对复合岩样的强度有显著影响；（2）随着夹层倾角增大，三轴试样产生大量剪切裂缝；随着夹层厚度增大，三轴试样由剪切破坏向张拉破坏转变；随着夹层层数增加，三轴试样呈现中间部位的张拉破坏；（3）当考虑露天矿山软弱夹层的蠕变特性时，其强度折减系数为1.16，比不考虑蠕变特性降低了约10%，可为实际工程提供更高的安全存储。

Study on slope stability of a mine considering creep characteristics of soft and weak interlayer

In order to study the influence of the existence state of weak interlayer on the strength and deformation characteristics of geotechnical body, PFC3D discrete element software is selected to carry out standard triaxial test simulation of composite rock samples under different conditions to deeply analyze its strength change law and deformation damage characteristics. With the help of FLAC3D software, a 3D model based on the actual project was established, and the Burgers model, which takes creep characteristics into account, was selected to conduct an in-depth analysis of the stability state of the slope of the open pit mine. The following conclusions were obtained:(1) Parameters such as dip angle, thickness and number of layers of the soft and weak interlayer all have significant effects on the strength of composite rock samples. (2) With the increase of the interlayer inclination, the triaxial specimens produce a large number of shear cracks; with the increase of the interlayer thickness, the triaxial specimens change from shear damage to tensile damage; with the increase of the number of interlayer layers, the triaxial specimens show tensile damage in the middle part. (3) When considering the creep characteristics of the soft and weak interlayer in the open pit, the strength reduction factor is 1.16, which is about 10% lower than not considering the creep characteristics and can provide higher safe storage for the actual project.