运用ANSYS法探讨软弱夹层对岩体破裂的影响

Application of ANSYS in discussing influence of weak interbed on rock fracture

徐珂 戴俊生 冯建伟 付晓龙 王硕 刘超

中国石油大学（华东）地球科学与技术学院，山东 青岛 266580

School of Geosciences, China University of Petroleum, Qingdao 266580, China

软弱夹层对岩体的稳定性有显著影响。为了探讨不同夹层特征对岩体破裂方式及规律的影响，文中首先对样品进行单轴压缩试验，得到各自的应力￣应变曲线；再利用ANSYS有限元软件进行数值模拟，生成应力、应变等参数在岩体上分布的图件；将应力￣应变曲线的特征分析与模拟结果分布图进行对比，结合岩石力学破裂理论，总结不同夹层特征下岩体的破裂规律。结果表明，软弱夹层对岩体破裂的影响主要体现在夹层的层数、厚度和间距。软弱夹层的层数越多，岩石抗压强度越大；而软弱夹层厚度越大，岩体抗压强度越低，容易破裂；夹层的间距增大，岩体的不连续性就增大，抗压强度降低，易于变形和破坏。岩石力学试验和数值模拟结果均成功验证了这个规律。这对含软层地质体的裂缝发育特征研究具有指导意义和参考价值。

Weak interbed is fundamental to the stability of rock mass. In order to discuss the crack mode and failure rules of rock mass resulted by different styles of interbeds, uniaxial compression experiment has been conducted on rock samples, various stress-strain curves are obtained. Using finite element numerical simulation with ANSYS, distribution maps of principal stress and principal strain on rock mass are generated. Comparing stress-strain curves with simulation distribution maps, combining the fracture theory of rock mechanics, the failure rules of rock mass for different features of weak interbed are summarized. The research suggests that the number of layers, thickness and spacing of weak interbed have great influence on failure of rock mass. In details, rock mass with more layers tends to be stronger than that with less layers, because weak interbed can act as a role of buffering. Rock mass with thick interbed would crack in priority, because of their redundant weak components. The discontinuity of rock mass has the positive correlation with spacing of interbeds, therefor, wide spacing would result in low compressive intensity and rock mass tends to generate fracture. Rock mechanics experiment and numerical simulation results have confirmed this rule successfully. This research provides guidance and reference for study on characteristics of fracture development of rock mass with weak interbed.

10.6056/dkyqt201506011