Abstract To investigate the influence of water on the mechanical behavior of rock surrounding hard-rock tunnels, a series of uniaxial and true-triaxial compression tests were performed on red sandstone samples with two different water contents (natural water content (NWC) and saturated water content (SWC)). The samples taken were cubic samples containing a circular hole and cylindrical samples. During the true-triaxial tests, hole failure was monitored and recorded in real-time with in-house developed monitoring equipment. The effects of water on the stress, energy, and fracture characteristics of rock failure in hard-rock tunnel were determined. The results indicate that, after reaching the SWC state, the strength and elastic modulus of red sandstone were reduced, and the shear characteristics became more obvious. The failure mode of the NWC holes was primarily slab ejection, while the failure mode of the SWC holes was primarily slab flaking. Water changes the mesoscopic mechanism of spalling and exhibits a double effect on hard-rock tunnels. The mechanisms of water on rockburst prevention are to reduce residual elastic strain energy, avoid excessive concentration of strain energy, and increase rockburst resistance. The ratio of the far-field maximum principal stress to the uniaxial compressive strength can be used as an index to evaluate the stability of hard-rock tunnels. The results help to rethink the influence of water on underground hard rock engineering, such as the failure mechanism of surrounding rock and the analysis of tunnel (or caverns) stability in water-rich stratum, and the mechanism of water on the rockburst prevention.

中文翻译：

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水对硬岩隧道围岩力学行为的影响：实验模拟

摘要 为研究水对硬岩隧道围岩力学行为的影响，对具有两种不同含水量（天然含水量（NWC）和饱和水）的红砂岩样品进行了一系列单轴和真三轴压缩试验。内容 (SWC))。所取样品为包含圆孔的立方体样品和圆柱形样品。在真三轴试验期间，使用内部开发的监测设备实时监测和记录孔洞故障。确定了水对硬岩隧道岩石破坏的应力、能量和断裂特性的影响。结果表明，达到SWC状态后，红砂岩的强度和弹性模量降低，剪切特性更加明显。NWC 孔的破坏模式主要是板坯弹出，而 SWC 孔的破坏模式主要是板坯剥落。水改变了剥落的细观机制，并对硬岩隧道表现出双重影响。水对防止岩爆的作用机制是降低残余弹性应变能，避免应变能过度集中，增加抗岩爆能力。远场最大主应力与单轴抗压强度的比值可作为评价硬岩隧道稳定性的指标。研究结果有助于重新思考水对地下硬岩工程的影响，如围岩破坏机制和富水地层隧道（或洞室）稳定性分析，以及水对岩爆预防的作用机制。