In the process of tunnel construction, gypsum rock is often encountered, and the volume of gypsum rock expands when encountering water, which is easy to cause the occurrence of rock fall, collapse, and other disasters, bringing serious challenges to the safe construction of the tunnel. Therefore, in this paper, four groups of samples under different moisture content are tested by ultrasonography, uniaxial compression, conventional triaxial compression, Brazilian splitting, X-ray diffraction, and SEM, and then the physical and mechanical properties of gypsum rock are studied, and the conclusion is as follows: the density of the water saturated sample, and the longitudinal wave velocity of the natural sample are the highest. Both the water saturation and dehydration conditions have a weakening effect on the remolded sample of high-strength gypsum powder. The peak intensity of the sample gradually increases with the increase of confining pressure, and the relationship between the peak intensity and confining pressure of the sample conforms to the Coulomb strength criterion. After high-temperature dehydration, the sample showed obvious plastic softening characteristics. The cohesion and internal friction angle of the sample are closely related to the water content. The cohesion is the largest in the 45°C dehydrated sample, the internal friction angle is the smallest in the saturated sample, whereas the cohesion is the smallest and internal friction is the largest in the high-temperature dehydrated sample. The characteristics of failure for the natural and 45°C dehydrated samples are almost the same and most samples show shear or shear-tensile failure. The shear plane begins at the edge of the end face of the sample and exhibits a typical diagonal shear failure. The high-temperature dehydrated samples are completely broken under uniaxial and triaxial compression conditions. After high-strength gypsum powder was used to make the remolded sample, the calcium sulfate disappeared, the water content increased, and the main mineral components of the natural and saturated samples were the same. After dehydration at 45°C, the sample began to release structural water and generate SiO₂. After high-temperature dehydration, the hemihydrate gypsum continued to dehydrate and become soluble anhydrous gypsum.

中文翻译：

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石膏样岩石材料的物理力学性能

在隧道施工过程中，经常遇到石膏岩，遇水时石膏岩的体积会扩大，容易引起岩崩，倒塌等灾害的发生，给安全施工带来了严峻的挑战。隧道。因此，本文通过超声，单轴压缩，常规三轴压缩，巴西劈裂，X射线衍射和SEM对四组不同水分含量的样品进行了测试，然后研究了石膏岩石的物理和力学性能，结论如下：饱和水样的密度和自然样的纵波速度最高。含水饱和度和脱水条件都对高强度石膏粉的重塑样品具有弱化作用。样品的峰值强度随围压的增加而逐渐增大，且峰值强度与围压的关系符合库仑强度准则。高温脱水后，样品表现出明显的塑性软化特性。样品的内聚力和内摩擦角与水含量密切相关。在45°C脱水样品中，内聚力最大，在饱和样品中，内摩擦角最小，而在高温脱水样品中，内聚力最小，内摩擦最大。天然样品和45°C脱水样品的破坏特性几乎相同，大多数样品都显示出剪切或剪切拉伸破坏。剪切平面始于样品端面的边缘，并表现出典型的对角剪切破坏。高温脱水后的样品在单轴和三轴压缩条件下会完全破裂。使用高强度石膏粉制作重塑样品后，硫酸钙消失，含水量增加，天然样品和饱和样品的主要矿物质成分相同。在45°C脱水后，样品开始释放结构水并生成SiO 剪切平面始于样品端面的边缘，并表现出典型的对角剪切破坏。高温脱水的样品在单轴和三轴压缩条件下会完全破裂。使用高强度石膏粉制作重塑样品后，硫酸钙消失，含水量增加，天然样品和饱和样品的主要矿物质成分相同。在45°C脱水后，样品开始释放结构水并生成SiO 剪切平面始于样品端面的边缘，并表现出典型的对角剪切破坏。高温脱水后的样品在单轴和三轴压缩条件下会完全破裂。使用高强度石膏粉制作重塑样品后，硫酸钙消失，水含量增加，天然样品和饱和样品的主要矿物质成分相同。在45°C脱水后，样品开始释放结构水并生成SiO 天然和饱和样品的主要矿物质成分相同。在45°C脱水后，样品开始释放结构水并生成SiO 天然和饱和样品的主要矿物质成分相同。在45°C脱水后，样品开始释放结构水并生成SiO₂。高温脱水后，半水石膏继续脱水并变成可溶的无水石膏。