考虑软化效应的隧道围岩自稳时间解析模型

发布时间：2018-04-27 23:37

本文选题：自稳时间 + 岩体分级　；参考：《工程科学与技术》2017年03期

【摘要】：现行隧道自稳时间解析法中未考虑地下水的软化作用,导致过高估计亲水软化性岩石的围岩质量。以具有典型软化特性的石膏岩为研究对象,探索水的软化作用对隧道围岩自稳时间的影响。采用试验和理论相结合的方法研究围岩自稳时间。首先,进行不同浸水时间下的石膏岩软化试验,研究其软化规律;通过试验获得石膏岩吸水率、弹性模量和泊松比分别与浸水时间之间的定量关系;在弹性模量与浸水时间及泊松比与浸水时间的定量关系中,引入完整性系数和富水系数,建立岩体力学参数软化方程。然后,基于经典的圆形轴对称隧道弹性解,考虑掌子面对隧道轴向位移的影响,推导出隧道临空面处无支护状态下的位移公式;把岩体力学参数软化方程嵌入此位移公式中,获得考虑软化效应的临空面位移解。最后,在此位移解中引入活跃跨度和围岩的临界位移值,建立考虑软化效应的隧道围岩自稳时间解析模型。该模型考虑了围岩体工程特性、岩石力学特性及岩石软化特性,能输出自稳时间与活跃跨度之间的关系曲线。经自洽分析法检验,该模型中自稳时间随各参数的变化规律与实际情况相符,模型具有自洽性。模型被应用于评价礼让隧道石膏围岩的自稳时间,现场反馈结果表明该模型更适合于现场应用。
[Abstract]:In the present analytical method of tunnel self-stability time, the softening of groundwater is not considered, which leads to overestimation of surrounding rock mass of hydrophilic softening rock. Taking gypsum rock with typical softening characteristics as the research object, the influence of water softening on the time of self-stabilization of tunnel surrounding rock is explored. The time of self-stability of surrounding rock is studied by combining test and theory. Firstly, the softening test of gypsum rock under different soaking time was carried out, and the quantitative relationship between water absorption, elastic modulus and Poisson's ratio of gypsum rock and soaking time was obtained. In the quantitative relationship between elastic modulus and soaking time and Poisson's ratio with soaking time, the integral coefficient and water-rich coefficient are introduced, and the softening equation of mechanical parameters of rock mass is established. Then, based on the classical elastic solution of circular axisymmetric tunnel, considering the influence of the face on the axial displacement of the tunnel, the displacement formula is derived under the condition of no support on the face of the tunnel, and the softening equation of the mechanical parameters of rock mass is embedded in the displacement formula. The solution of face displacement considering softening effect is obtained. Finally, the critical displacement values of active span and surrounding rock are introduced into the displacement solution, and an analytical model of tunnel surrounding rock self-stability time considering softening effect is established. The model takes into account the engineering characteristics of surrounding rock, the mechanical properties of rock and the softening of rock, and can output the curve between the self-stability time and the active span. The results of self-consistent analysis show that the variation of self-stability time with each parameter is consistent with the actual situation, and the model has self-consistency. The model is applied to evaluate the self-stability time of gypsum surrounding rock in Licheng tunnel. The field feedback results show that the model is more suitable for field application.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;
【基金】：国家自然科学基金资助项目(51074198) 重庆市研究生科研创新项目资助(CYB15011)
【分类号】：U451.2

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