地震作用下节理岩体的抗震稳定性分析

Seismic Stability and Permanent Displacement of Joint Rock Slope

基于统一强度理论和极限平衡原理,结合节理岩体的特点,提出一个能考虑岩体拉裂破坏及岩体种类等因素的边坡安全系数和永久位移的计算方法。初步分析了地震荷载作用下坡度、节理面倾角、拉裂深度、地震荷载及强度参数对抗震稳定性的影响。研究结果表明:随着中间主应力的发挥,边坡的安全系数相应增加,而永久变形明显地减小。在实际工程中,合理考虑中主应力效应的影响,能使岩土类材料的潜在强度得到充分发挥,也可间接地产生巨大的经济效益。

Earthquake effects are commonly considered in the stability analysis of rock slopes and other earth structures. The conventional approach is often based on the limit equilibrium method by Mohr-Coulomb or Hock -Brown failure criterion. However, experimental data shows the rock failure doesn＇t keep to simplex criterion and it is influenced by the intermediate principal stress distinctly. A new method for evaluating seismic safety factor and permanent displacement of rock slopes is proposed according to the characteristic of joint rock. The unified strength theory is introduced into the limit equilibrium method. In this method, the strength difference and tensile failure can be considered. The influences of angle of bedding slope, inclination of joint, unified strength parameter, tensile depth and seismic load are investigated. The results reveal that, with the increase of intermediate principal stress effect, the safety factor also increases, but the permanent displacement is descended obviously. In practical engineering, the potential strength of filling materials should be sufficiently developed under the guidance of the unified strength theory.