A nonlinear creep model of hard structural planes.

Area of Science:

• Geotechnical Engineering
• Rock Mechanics
• Civil Engineering

Background:

• Creep characteristics of hard structural planes are critical for rock slope stability.
• Traditional models exhibit limitations in adaptability and parameter interpretability for hard structural planes.

Purpose of the Study:

• To develop a novel, piecewise nonlinear constitutive model for hard structural planes.
• To improve the accuracy and physical meaning of parameters in creep behavior modeling.
• To provide a theoretical basis for enhanced rock slope stability analysis.

Main Methods:

• An element combination model was adapted and improved based on creep failure mechanisms.
• New parameters were introduced for instantaneous deformation (plastic deformation proportional coefficient n), attenuation creep (hardening coefficient C, creep index m), and viscoelastic-plastic failure (weakening factor k).
• The constitutive relationship was established, and the creep equation was derived through integration.

Main Results:

• A new piecewise nonlinear constitutive model for hard structural planes was successfully established.
• Model validation using creep test data from sandstone and marble structural planes yielded fitting results exceeding 0.95.
• The improved model demonstrated higher accuracy in nonlinear characteristics during attenuation and acceleration creep stages.

Conclusions:

• The developed piecewise model accurately captures the complex creep behavior of hard structural planes.
• The model offers clearer physical interpretations of parameters and improved adaptability compared to traditional methods.
• This research provides a robust theoretical foundation for more reliable rock slope stability assessments.