Matsuoka-Nakai破坏准则的拓展应用

Extended application for Matsuoka-Nakai failure criterion

Matsuoka-Nakai破坏准则有两个缺点:一是没有考虑岩土类材料的内聚力对材料的强度贡献,二是它与子午面的交线是直线,基于此,提出了一个拓展的Matsuoka-Nakai破坏准则.该准则在保持Matsuoka-Nakai破坏准则优点的基础上,考虑了岩土类材料的内聚力对其破坏强度的影响,且在子午面上呈现为外凸的曲线形状,因而能更合理地模拟岩土类材料的强度特性.红砂岩的真三轴试验资料检测了该拓展的Matsuoka-Nakai破坏准则的有效性.最后借助该拓展的破坏准则,通过寻求试验强度与预测强度之间的误差函数最小值的方法,提出了一个评估试验中难以测准的岩土类材料抗拉强度的计算方法.

The Matsuoka- Nakai failure criterion has two disadvantages： the first is the criterion not including cohesion＇ contribution to failure strength, the second is a linear meridian on meridian plane. Based on improvement about the two disadvantages, an extended Matsuoka -Nakai failure criterion is proposed. Comparison test results of red sandstone with their predicting results show that the extended Matsuoka - Nakai criterion could capture important strength characteristics such as tensile stress, friction, and curved meridian et al. of geo - material with good accuracy. At last, through searching for the minimum value of error function between test and prediction data, the extended Matsuoka -Nakai failure criterion supports a new way to obtain tensile strength of geotechnical material which is usually difficult to be measured by tests.