基于自锁概念的岩体弱面破坏模型与规律研究  

Rock mass failure with self-locking concept

作　　者：张广清[1] 陈勉[1] 

机构地区：[1]中国石油大学(北京)石油天然气工程学院,北京102249

出　　处：《岩土工程学报》2009年第7期1052-1058,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(90510005);高等学校博士学科点专项科研基金项目(20070425026)

摘　　要：采用摩擦学中的自锁概念提出了确定弱面破坏的模型和分析方法,物理概念简单明确。采用自锁概念分析二维弱面破坏与采用莫尔–库仑定律得到的结果一致。三维弱面模型在弱面与中间主应力平行和中间主应力等于最小主应力两种情况下,可退化为二维弱面问题。研究结果表明:主应力、弱面力学参数对空间弱面破坏角度范围的影响显著,包括破坏角度范围大小和形态变化两个方面。随着弱面力学参数的增加,空间弱面破坏角度范围有变小的趋势,当弱面力学参数达到一定数值后,岩体中的弱面倾角和走向取任意值,岩体均不会发生弱面破坏。随着中间主应力和最小主应力的增加,空间弱面破坏角度范围具有变小的趋势。通过建立局部坐标系,得到了裂缝性地层井壁发生失稳的弱面角度随井底压力变化的规律。A three-dimensional model for rock mass failure is proposed based on the self-locking concept in friction analysis. In case of two-dimensional problems, the model gives the same results as those of Mohr-Coulomb criterion. And the three-dimensional model can be reduced to traditional two-dimensional model if the weak plane is parallel to the middle principal stress and/or the middle stress is equal to the minimum principal stress. The results indicate that the influences of the principal stresses and mechanical parameters of the weak plane on the spatial failure region are remarkable in terms of shape and range, that the spatial failure region becomes smaller as the mechanical parameters increase, and that the weak plane will never fail when some threshold of mechanical parameters is reached, no matter what values of weak plane strike and dip will be And the spatial failure region becomes smaller with the increased values of the middle and minimum principal stresses. Then, the influence of bottom hole pressure on the failure range of weak plane is analyzed for bore holes in naturally fractured formation, with the help of the local coordinate system.

关 键 词：自锁 摩擦锥 三维弱面 莫尔-库仑定律 

分 类 号：TU458[建筑科学—岩土工程]