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湿度对岩体结构性能的影响显著,不仅造成岩体物理力学性能弱化,还在一定程度上产生湿涨变形,进而改变岩体的应力状态,大大增强岩体的时效变形特性。为了分析节理岩体在高湿度环境下的时效变形,采用湿度-应力-损伤耦合数值模型对水敏感岩体隧洞开挖后的变形量、围岩内的湿度扩散,以及应力演化进行了数值分析。通过对单组和2组节理岩体的变形、应力、湿度扩散的分析,揭示了节理弱面对湿度扩散和岩体变形的强化作用。开挖隧洞拱顶和底板变形量的分析结果表明高湿度环境是水敏感岩体隧洞产生底鼓的重要原因之一。湿度扩散引起隧洞顶部和底部围岩产生大量破坏,致使相应部位的位移量陡增。此外,单组节理对岩体的湿度扩散的方向起到明显的导向作用,而多组相互斜交的节理则在一定程度上削弱了湿度扩散的各向异性。
Humidity has a significant impact on the structural properties of rock mass, which not only weakens the physical and mechanical properties of the rock mass, but also produces wet deformation to a certain extent, which in turn changes the stress state of the rock mass and greatly enhances the aging deformation characteristics of the rock mass. In order to analyze the age-dependent deformation of jointed rock masses in high-humidity environment, the numerical analysis of the deformation after water-sensitive rock tunnel excavation, the moisture diffusion in the surrounding rock and the stress evolution are carried out by using the coupled numerical model of humidity-stress-damage . Through the analysis of the deformation, stress and humidity diffusion of single and two groups of jointed rock mass, the strengthening effect of joint weakness on the diffusion of moisture and the deformation of rock mass is revealed. The results of excavation tunnel dome and floor deformation analysis show that high humidity environment is one of the important reasons for the bottom drum of water-sensitive rock tunnel. Moisture diffusion caused a great deal of damage to the rock at the top and bottom of the tunnel, resulting in a sharp increase in the displacement of the corresponding part. In addition, the single set of joints plays a significant guiding role in the direction of rock mass moisture diffusion, while the groups of skewed joints weaken the anisotropy of humidity diffusion to a certain degree.