红砂岩剪切蠕变特性试验研究与边坡失稳机理分析

以标准红砂岩试样为研究对象，运用自行研制开发的软弱煤岩材料剪切蠕变实验装置结合自行开发的煤岩 细观力学特性测控软件，对处于不同载荷水平作用下的红砂岩试样剪切蠕变力学特性进行了系统的研究,并 基于试验结果尝试解释了一些边坡失稳发生时的现象。结果表明:载荷大小对红砂岩剪切蠕变力学特性具有 明显的影响，直接决定着加速剪切蠕变阶段的有无、试样的破坏与否和试验时间对其剪切蠕变力学特性的 影响程度；存在2个特殊的临界剪切蠕变载荷值τ₁、τ₂，它们将红砂岩剪切蠕变类型分为3种， 即肯定不破坏、不一定破坏和肯定破坏；红砂岩试样破裂带的形成过程表现为渐进式，破坏过程表现为渐 进式与突发式结合，破裂面附近区域为裂纹结构丰富区且该面为非平直剪切面;不同载荷水平作用下岩石剪 切蠕变力学特性可以用来解释边坡失稳发育过程中的现象，认为边坡内潜在滑移带内岩石发生的剪切蠕变 破坏是边坡发生失稳的力学机理。

Experimental Research on Shear Creep Properties of Red Sandstone and Analysis on Slope Stability Mechanism

Taking the standard red sandstone samples as research objects，both the self-designed shear creep experimental device of coal or weak rock and the monitor software of coal or rock micromechanics properties were used to make the systematic studies on shear creep properties of red sandstone under different load levels.The phenomena and mechanisms of slope stability occurrence are trial to be revealed based on the conclusions from experiments.The results show：load levels have a significant effect on the shear creep mechanical properties of red sandstone，which will mainly determine the presence of accelerated shear creep stage or not， the destruction of the sample or not and the affect extent of creep test time on mechanical properties.There are two special shear creep stress，τ₁、τ₂,which divides the shear creep of sandstone into three types，certainly not fracture，uncertainly fracture and certainly fracture.The formation process of damage area of red sandstone was showed as a progressive type，and the damage process was showed as a progressive type combined with burst type.There is crack-rich area near the fracture surface，and the fracture surface is not flat shear plane in structure.Shear creep properties of red sandstone under different load may be used to reveal the phenomena and mechanisms of slope stability occurrence.It is considered that rock shear creep of potential slip area in slope is the physical mechanism of slope instability.