Tresca Model for Geotechnical Engineering

Tresca Model

1. Critical state soil mechanics Tresca model (max. Shear stress Theory) Rameez Riyaz (2021MCIVGT006) Eiqan Shafi (2021MCIVGT017) Shahid Manzoor Bhat (2021MCIVGT002)

2. Introduction

3. Failure theory models Mohr – Coulomb Model Hardening Soil Model / Hardening Mohr – Coulomb Model Modified Cam – Clay Model Drucker – Prager Model Tresca Model Hoek – Brown Model Duncan – Chang Model

4. Tresca model (max. Shear stress theory) Failure occurs when maximum shear stress in a complex stress system equals to the maximum shear stress at yield point under uniaxial loading. No failure occurs if maximum shear < Y/2

5. Pure shear case Shear Yield = 0.5x Tensile Yield

6. 3D Stress state In 3D stress state, principal stresses are => Maximum shear stress: Yield function:

7. Yield function in Principal stress space

8. Tresca hexagon

9. 2d stress state Each equation represents two lines in 2D stress space

10. Conclusion This theory is suitable for ductile materials For pure shear case it is oversafe Limitations Not applicable for materials subjected to hydrostatic loading as it says shear stress will be zero and material will never fail which is practically impossible Not applicable for brittle materials as they have different yield stress in tension and compression

11. Thank you