Experimental investigation and constitutive model for lime mudstone

Area of Science:

• Geotechnical Engineering
• Rock Mechanics
• Materials Science

Background:

• Understanding the mechanical properties of lime mudstone is crucial for geotechnical applications.
• Existing models may not fully capture the complex stress-strain behavior of lime mudstone during failure.

Purpose of the Study:

• To investigate the mechanical properties of lime mudstone under varying confining pressures.
• To develop and validate a new constitutive model for describing lime mudstone's axial stress-strain behavior during failure.

Main Methods:

• Conventional triaxial compression tests were conducted on lime mudstone samples at confining pressures of 0, 5, 15, and 20 MPa.
• Data analysis involved characterizing the relationship between confining pressure and peak stress, peak strain, and elastic modulus.
• A new constitutive model was proposed and compared against experimental data and an existing model (Wang's model).

Main Results:

• Axial peak stress and elastic modulus of lime mudstone increase linearly with confining pressure.
• Axial peak strain exhibits a power-law relationship with increasing confining pressure.
• The proposed constitutive model accurately simulates the strain softening and axial stress-strain response of lime mudstone during rock failure.

Conclusions:

• Confining pressure significantly influences the mechanical behavior of lime mudstone.
• The newly developed constitutive model offers improved accuracy in predicting lime mudstone's stress-strain response, particularly its strain-softening characteristics.