Deformation and failure mechanism of horizontal soft and hard interlayered rock under uniaxial compression based on digital image correlation method
Deformation and failure mechanism of horizontal soft and hard interlayered rock under uniaxial compression based on digital image correlation method
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DOI：
10.1016/j.engfailanal.2022.106823
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发表时间：
2022-09-28
影响因子：
4
通讯作者：
Lv, Xinxin
中科院分区：
文献类型：
--
作者：
Luo, Pingkuang;Wang, Lichuan;Lv, Xinxin
在软硬互层缓倾岩层中修建隧道时，隧道底部围岩的变形会导致运营期间的底板隆起、结构破坏和轨道不平顺。为此，为了研究软硬互层岩石的变形行为，设计了一种特殊的金属模具，对试样的某一侧进行了单轴压缩试验的位移约束。制备了一系列不同高长比的软硬互层类岩石试样。研究了水平软硬互层类岩石试样在单轴压缩条件下的变形特征和破坏特性。试验结果表明，水平软硬互层类岩石试样的单轴抗压强度峰值随高长比的增大而减小。水平软硬互层类岩石试样的破坏是软硬层材料在压应力作用下的耦合破坏过程。试件的破坏过程以轴向劈裂和屈曲为主。基于数字图像相关技术（DIC），分析了试件的位移与应力之间的关系。在相同的应力值下，外层的位移大于内层的位移。软岩层的应变和位移大于硬岩层。试验结果与工程实际相吻合，较好地解释了隧道底部软硬互层围岩抬升的机理。
The deformation of bottom rock masses surrounding a tunnel may lead to floor upheaval, structural damage and track irregularity during operation when the tunnel is constructed in soft and hard interlayered rock strata with gently dipping layers. Therefore, in order to study the deformation behavior of soft and hard interlayered rock, a special metal mold was designed to restrain the displacement of a certain side of the samples for the uniaxial compression test. A series of soft and hard interbedded rock-like samples with different height-length ratios were prepared. The deformation characteristics and failure properties of horizontal soft and hard interbedded rock-like samples were studied under uniaxial compression. The test results show that the peak uniaxial compressive strength of the horizontal soft and hard interbedded rock-like samples decreases with the increasing of the height-length ratios. The failure of the horizontal soft and hard interlayered rock-like samples is a process of coupling failure of the soft layer material and the hard layer material under compressive stress. The failure process of the sample is dominated by axial splitting and buckling. Based on the digital image correlation (DIC) tech-nology, the relationship between the displacement and stress of the sample was analyzed. Under the same stress value, the displacement of the outer layer is greater than that of the inner layer. The strain and the displacement of the soft rock layer are greater than those of the hard rock layer. The test results are consistent with the engineering reality and explain well the mechanism of the soft and hard interlayered surrounding rock lifting at the bottom of the tunnel.