Ground response curves for rock masses exhibiting strain-softening behaviour
Ground response curves for rock masses exhibiting strain-softening behaviour
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DOI：
10.1002/nag.315
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发表时间：
2003-11-01
影响因子：
4
通讯作者：
Carranza-Torres, C
中科院分区：
文献类型：
--
作者：
Alonso, E;Alejano, LR;Carranza-Torres, C
文献综述表明，有足够的技术来获得在弹脆性和理想塑性材料中开挖的隧道的地面反应曲线。然而，对于应变软化材料，似乎没有充分分析这个问题。本文提出了一种求解在应变软化材料中开挖的圆形隧道的地基反力曲线（GRC）的一维数值解法，该问题以非常一般的形式表示，并归结为一个常微分方程组。通过适当地定义一个虚拟的“时间”变量和重新标度一些变量，将问题转化为一个初值问题，并在MATLAB环境下实现了Runge-Kutta-Fehlberg方法，该方法已被开发用于各种常见的特殊行为模型，包括Tresca，Mohr-Coulomb和Hoek-Brown破坏准则，在所有情况下，采用非关联流动规则和与主应变相关塑性参数相关的两段分段线性函数来模拟峰值和剩余失效准则之间的过渡。其与封闭形式的解（如果存在的话）或基于FDM的代码结果很好地一致。参数的研究和具体的图表创建突出不同parameters.The建议的方法的影响，旨在成为一个更广泛的和一般的数值基础，标准和新功能的行为模式，专注于获得GRC隧道开挖应变软化材料可以实施。这种解决此类问题的方法已被证明比使用基于FEM或FDM的数值2D代码更有效且耗时更少。版权所有（C）2003约翰威利父子有限公司。
A literature review has shown that there exist adequate techniques to obtain ground reaction curves for tunnels excavated in elastic-brittle and perfectly plastic materials. However, for strain-softening materials it seems that the problem has not been sufficiently analysed. In this paper, a one-dimensional numerical solution to obtain the ground reaction curve (GRC) for circular tunnels excavated in strain-softening materials is presented.The problem is formulated in a very general form and leads to a system of ordinary differential equations. By adequately defining a fictitious 'time' variable and re-scaling some variables the problem is converted into an initial value one, which can be solved numerically by a Runge-Kutta-Fehlberg method, which is implemented in MATLAB environment.The method has been developed for various common particular behaviour models including Tresca, Mohr-Coulomb and Hoek-Brown failure criteria, in all cases with non-associative flow rules and two-segment piecewise linear functions related to a principal strain-dependent plastic parameter to model the transition between peak and residual failure criteria.Some particular examples for the different failure criteria have been run, which agree well with closed-form solutions-if existing-or with FDM-based code results. Parametric studies and specific charts are created to highlight the influence of different parameters.The proposed methodology intends to be a wider and general numerical basis where standard and newly featured behaviour modes focusing on obtaining GRC for tunnels excavated in strain-softening materials can be implemented. This way of solving such problems has proved to be more efficient and less time consuming than using FEM- or FDM-based numerical 2D codes. Copyright (C) 2003 John Wiley Sons, Ltd.