Permeability Coefficient of Concrete under Complex Stress States

Area of Science:

• Civil Engineering
• Geotechnical Engineering
• Materials Science

Background:

• Hydraulic structures face risks from concrete cracking and seepage failure due to long-term hydraulic loading.
• Accurate analysis of concrete failure under seepage-stress coupling is crucial for structural safety.
• Comprehending concrete permeability variations under complex stress is essential.

Purpose of the Study:

• To investigate the variation law of concrete permeability coefficients under multi-axial loading conditions.
• To establish a relationship between permeability coefficients, axial strain, confining pressure, and seepage pressure.
• To develop a scientific basis for analyzing concrete seepage-stress coupling failure processes.

Main Methods:

• Concrete samples were subjected to multi-axial loading, including confining, seepage, and axial pressures.
• Permeability experiments were conducted to measure permeability coefficients under varying stress conditions.
• The relationship between permeability and volume strain was established and applied to numerical simulations.

Main Results:

• The study revealed the relationships between concrete permeability coefficients and axial strain, confining pressure, and seepage pressure.
• A four-stage permeability variation law was identified during axial pressure application, with causes analyzed.
• An exponential relationship between the permeability coefficient and volume strain was established.

Conclusions:

• The established exponential relationship provides a scientific basis for analyzing concrete seepage-stress coupling.
• The findings are applicable to numerical simulations for assessing the safety of hydraulic concrete structures.
• Understanding permeability variations is key to preventing seepage failure and ensuring structural integrity.