摘要
本文介绍了节理的断裂力学机制研究进展.从岩石断裂力学观点出发,节理是以张开位移为主的断裂构造,节理面结构可以通过由裂源点、羽纹和奋状标志组成的羽状构造表征.研究表明,节理起源于局部张应力.在压应力场下,颗粒接触面、包裹体、孔隙及微裂隙等均可产生局部张应力,因而在这些部位都可能成为节理的起始点.孔隙液压的存在是节理形成的重要因素.节理扩展特性可通过岩体应力强度因子(K)或应变能释放率(G)加以研究,单一型(Ⅰ型、Ⅱ型或Ⅲ型)及复合型(Ⅰ—Ⅱ型、Ⅱ—Ⅲ型或Ⅰ—Ⅲ型)节理的扩展特性主要取决于应力强度因子比 K_Ⅱ/K_Ⅰ或 K_Ⅲ/K_Ⅰ的数值.
From the view of rock fracture mechanics, joints are fractures with dominant opening displacements and the joint surface morphology features plumose structures which include the origins, hackles and rib marks. Joints are initiated from the points where the local tensile stresses are concentrated. In the compressive stress field,grain contacts,inclusions,pores and microcracks can induce local tensile stresses and thus facilitate the formation of joints. Yet, fluid pressure palys a very important role in the formation of joints. The character of joint propagation can be evaluated by the stress intensity factor (K) or the strain energy release rate (G) of rocks. The ways in which the single mode (Mode Ⅰ,Ⅱ or Ⅲ ) joints and the mixed mode (Mode Ⅰ - Ⅱ ,Ⅱ - Ⅲ or Ⅰ - Ⅲ ) joints propagate are determined by the stress intensity factor ratios KⅡ /KⅠ or KⅢ /KⅠ.
出处
《地质科技情报》
CAS
CSCD
北大核心
1991年第2期17-25,共9页
Geological Science and Technology Information
