深埋软岩非线性流变模型及隧道施工时效性规律研究

项目名称： 深埋软岩非线性流变模型及隧道施工时效性规律研究

项目编号： No.51508037

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑科学

项目作者： 陈亮

作者单位： 长沙理工大学

项目金额： 20万元

中文摘要： 弹塑性理论是常用的隧道力学分析的主要手段之一，然而它无法解释和预测隧道围岩变形所表现出的时效性特征，流变理论能较好的克服这一缺点。现有流变本构模型存在一定的描述偏差和参数不确定性，难以推广应用到实际工程中。因此，需要更为准确且易于使用的本构模型及分析方法。本课题在引入分数阶微积分理论和损伤理论的基础上，探索一种新的基于分数阶非线性蠕变损伤模型。主要研究内容为：（1）建立基于分数阶非线性蠕变损伤的本构模型，并推导出本构方程和蠕变方程；（2）研究本构方程的有限差分转化形式及其在数值分析中的应用方法；（3）考虑深埋软岩隧道施工过程，研究围岩蠕变位移的数学解析表达；（4）建立深埋软岩隧道三维仿真模型，研究其流变特征和开挖预留变形量设计方法。研究手段包括等围压三轴蠕变压缩试验、理论解析和数值分析。研究成果有助于深入揭示深埋软岩隧道施工时效性规律，促进流变理论的发展及其在隧道工程中的应用。

中文关键词： 软岩隧道；本构模型；分数阶微积分；解析解；数值分析

英文摘要： The elastoplastic theory is often one of the main methods for tunnel mechanical analyses so far, but it can’t be used for interpretation and prediction of the time-dependent behavior of rock deformation that can usually be well overcome by the rheological theory. The existed rheological constitutive models have disadvantages of description error and parameter uncertainty, and are very difficult to be utilized in actual projects. A more accurate and easy-used constitutive model and analysis method is obviously needed. This study is to investigate a new constitutive model based on the fractional calculus theory and damage theory. The main research of this study is as follows. Firstly, a new rheological constitutive model is to be established based on the fractional calculus theory and damage theory, and the constitutive equation and creep equation is derived. Secondly, a finite difference transforming form of the constitutive equation and its application in numerical analysis is then studied. Thirdly, a study on analytical solution of time-dependent deformation is carried out by taking account of the construction process of the soft rock tunnel with a deep overburden. Finally, a three-dimensional simulation model of soft rock tunnel with deep overburden is established in order to examine the rheological characteristics and the design method of reserved rock deformation. The research method to be used in this study includes three-dimensional rheological compression test, theoretical analysis and numerical modeling. The research achievement helps to reveal the time-dependent pattern of soft rock tunnel with a deep overburden, and to promote the development of rheological theory and its application in tunnel engineering.

英文关键词： soft rock tunnel;constitutive model;fractional calculus;analytical solution;numerical analysis