Cosserat介质理论针对节理岩体的应用

Cosserat theory and its application to jointed rockmasses

由于考虑了内在尺度的影响,Cosserat 介质理论较传统连续介质力学更精确和一般化,在考虑具有微结构介质的力学行为时拥有优势。节理岩体的力学性质明显受结构面影响控制,传统连续介质理论对于认识结构应力、应变的真实状况是有限度的。Cosserat 理论应用于岩土介质模拟时,根据具体情况有三种方式:一种是将岩土介质视为粒状材料,第二种则是将节理岩体看作是层状材料,此种模型应用最为常见;另一种则是将高度节理化岩体看作是块体结构。与试验或其它数值计算的对比表明,采用层状和块状模型对节理岩体进行数值模拟得到的分析成果是合理可信的。空间模型的应用也作了讨论。

With considering the influence of characteristic length of the medium, Cosserat continuum theory is superior to classical continuum theory to describe the mechanical behaviors of the materials with microstructure; and it becomes hotspots and has caught attention of the researchers widely. Classical continuum theory is its special case when characteristic length reduces to zero. Since the mechanical behavior of jointed or layered rockmasses have been effected and controlled by joints and faults, and rockmasses can’t be taken as traditional continuum any longer; it is limited for understanding the mechanical behaviors fully if still dealing them with classical continuum theory. There are three kinds of models, known as layered model, granular model and blocky model, when Cosserat theory adopted in geomechanics according to idiographic conditions and the shapes of the material microstructure. The layered model and blocky model are used widely when considering jointed rockmasses. The Cosserat numerical results, obtained with Cosserat layered or blocky model, have been compared with tests or other numerical outcome; and it shows that Cosserat theory is effective. Three-dimension model has been discussed too.